MP2617H_技术文档

MP2617H

Wide input Voltage, 3A, Switching Charger

With NVDC Power Path Management

For Single Cell Li+ Battery

DESCRIPTION

FEATURES



4V to 14V Operating Input Voltage

Smart Power Path Management

Five Control Loops: Input Current Limit,

Input Voltage Limit, Constant Charge

Current, Terminal Battery Control, and

Thermal Foldback

1.6MHz Switching Frequency

Programmable Input Current Limit

Programmable Charge Current

Single Input for USB and AC Adapter

Covers USB2.0 and USB3.0 Input

Specifications

Fully Integrated Power Switches

No External Blocking Diode or Sense

Resistor Required

Charging Operation Indicator

Built-In Programmable Charging Timer

Thermal Limiting Regulation on Chip

Battery Temperature Monitor

Available in a QFN-20 (3mmx4mm)

Package

The MP2617H is a monolithic, switch-mode,

battery charger with power path management

for single-cell Li-ion batteries in a wide range of

tablets and other portable devices. The

MP2617H integrates a synchronous buck

regulator that provides regulated voltage to

power the system output and charge the battery

simultaneously. The MP2617H supports both

USB and high-power DC adapter inputs. In

USB mode, the input current limit can be

programmed to 450mA or 825mA via the logic



pins

to

cover

USB2.0

and

USB3.0

specifications. When the adapter input is

present, the input current can also be limited to

avoid overloading the DC adapter. The input

current limit can be programmed up to 3A.



Smart power path management allows the

MP2617H to regulate the system voltage for

powering an external load and charging the

battery independently and simultaneously. This

allows for immediate system operation, even

under missing or deeply discharged battery

conditions. When the input current limit is

reached, the system load is satisfied first, and

then the charger uses the remaining current to

charge the battery. Additionally, the smart

power path control allows for an internal

connection from the battery to the system to

supplement additional power to the load in the

event the system power demand increases over

the input-limited power or the input is removed.

APPLICATIONS



Smartphones

E-Books

GPS

Portable Media Players

Portable Handheld Solutions

Tablet PCs

All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive.

For MPS green status, please visit the MPS website under Quality

Assurance. “MPS” and “The Future of Analog IC Technology” are registered

trademarks of Monolithic Power Systems, Inc.

The MP2617H features high integration with all

power switches integrated internally. No

external MOSFET, blocking diode, or current

sense resistor is required.

Two status monitor output pins are provided to

indicate the battery’s charge status and power

source status. Other features include trickle

charge, battery temperature monitoring, and

timer and thermal limiting regulation on the chip.

The MP2617H is available in a QFN-20

(3mmx4mm) package.

MP2617H Rev. 1.03

1/15/2018

www.MonolithicPower.com

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1

MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

PRELIMINARY SPECIFICATIONS SUBJECT TO CHANGE

TYPICAL APPLICATION

ON

OFF

AC adapter

/USB input

VILIM

M0

M1

EN

L

SYS Load

SW

IN

R3

R4

C1

C3

C_SYS

CHGOK

BST

SYS

ACOK

VCC

R1

SYSFB

PGND

R_T1

C_IN

C2

NTC

R2

I_CHG

BATT

vBATT

TMR

AGND

R_T2

C_BATT

C_TMR

R_NTC

ISET

ILIM

MP2617H

R_ISET

R_ILIM

0

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

ORDERING INFORMATION

Part Number

Package

Top Marking

MP2617HGL*

QFN-20 (3mmx4mm)

MP2617H

* For Tape & Reel, add suffix –Z (e.g. MP2617HGL–Z)

TOP MARKING

MP: MPS prefix

Y: Year code

W: Week code

2617H: Product code of MP2617HGL

LLL: Lot number

PACKAGE REFERENCE

TOP VIEW

20 19 18 17

1

2

3

4

5

6

16

BST

NTC

15 ISET

SW

IN

14 BATT

13

SW

PGND

SYS

SYSFB

12

11

AGND

EN

7

8

9

10

QFN-20 (3mmx4mm)

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

PIN FUNCTIONS

Package

Pin #

Name Description

Bootstrap. A capacitor is connected between SW and BST to form a floating supply across

the power switch driver to drive the power switch’s gate above the supply voltage.

1

BST

Switch output. Add an external 30V/1A Schottky diode from SW to GND when V_INis higher

or equal to12V and the output power include system load and battery charging is over 10W.

2, 4

SW

IN

3

5

Power input of the IC from adapter or USB.

PGND Power ground.

_____

Function logic control of the IC. Drive EN to logic low to enable the part. Drive EN to logic

high to disable the part.

6

EN

7

8

M0

M1

Mode select input. M0 sets the input current limit mode in combination with M1.

Mode select input. M1 sets the input current limit mode in combination with M0.

_____________

Open-drain output. CHGOK is pulled low during charging. CHGOK is pulled high through

9

CHGOK

an external resistor to VCC to indicate that the charge is complete.

__________

Open-drain output. ACOK is pulled low to indicate the presence of a valid input power

__________

10

ACOK

supply. ACOK is pulled high through an external resistor to VCC to indicate an invalid or

removed input.

11

12

AGND Analog ground.

SYS voltage program. Connect a resistor divider from SYSFB to SYS and AGND to

SYSFB

program the system output voltage. Leave SYSFB floating to disable the function.

13

14

SYS DC/DC regulator output to power the system load and charge the battery.

BATT Positive battery terminal.

Charge current program. A resistor from ISET to AGND can program the charge current

during CC charging. Float ISET to disable the charge function.

15

16

17

ISET

Thermistor input. Connect a resistor from NTC to VCC and the thermistor from NTC to

ground. The thermistor is inside the battery pack.

NTC

Input current limit program. A resistor from ILIM to AGND can program the input current

limit with the adapter input.

ILIM

18

19

20

TMR Set timer-out period. Connect TMR to AGND to disable the internal timer.

VLIM Input voltage limit program.

VCC Supply voltage of the IC.

MP2617H Rev. 1.03

1/15/2018

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

ABSOLUTE MAXIMUM RATINGS ⁽¹⁾

IN, SW ......................................... -0.3V to +20V

BATT, SYS .................................... -0.3V to +6V

BST ............................................. -0.3V to +26V

All other pins.................................. -0.3V to +6V

Thermal Resistance ⁽⁴⁾θ_JA

QFN-20 (3mmx4mm) ............ 48.......11 ... °C/W

θ_JC

NOTES:

1) Exceeding these ratings may damage the device.

2) The maximum allowable power dissipation is a function of the

maximum junction temperature T_J(MAX), the junction-to-

ambient thermal resistance θ_JA, and the ambient temperature

T_A. The maximum allowable continuous power dissipation at

any ambient temperature is calculated by P_D(MAX) = (T_J

(MAX)-T_A)/θ_JA. Exceeding the maximum allowable power

dissipation produces an excessive die temperature, causing

the regulator to go into thermal shutdown. Internal thermal

shutdown circuitry protects the device from permanent

damage.

(2)

Continuous power dissipation (T_A= +25°C)

QFN-20 (3mmx4mm).................................2.6W

Junction temperature...............................150°C

Lead temperature ....................................260°C

Storage temperature..................-65°C to 150°C

Recommended Operating Conditions ⁽³⁾

Supply voltage (IN) ......................... 4.0V to 14V

Operating junction temp. (T_J) ...-40°C to +125°C

3) The device is not guaranteed to function outside of its

operating conditions.

4) Measured on JESD51-7, 4-layer PCB.

MP2617H Rev. 1.03

1/15/2018

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

ELECTRICAL CHARACTERISTICS

V_IN= 5.0V, T_A= 25°C, unless otherwise noted.

Parameters

Symbol Condition

Min

Typ

Max Units

Input Power (IN)

IN operating range

V_IN

4.0

3.65

3.35

240

40

14 ⁽⁵⁾

3.95

3.65

320

120

3.1

V

Rising

Falling

Rising

Falling

3.8

3.5

IN under voltage lockout

threshold

V

280

70

mV

V

IN vs. BATT threshold

Rising

V_BST-V_SW

2.7

2.9

BST voltage threshold

Switching frequency

Falling

2.55

1.4

2.75

1.6

2.95

1.8

V

MHz

mA

USB2.0 mode

400

750

450

825

500

900

USB3.0 mode

Input current limit

I_IN

Default mode

1840 2000 2160

Programmable mode, R_ILIM= 23kΩ

Input current limit reference

voltage

V_ILIM

1.1

1.14

1.18

V

High-side NMOS on

resistance

R_{H_DS(ON)}Include the block MOSFET

120

80

130

100

5.8

mΩ

A

Low-side NMOS on resistance R_L__DS(ON)

High-side NMOS peak current

limit

3.8

4.8

Input voltage clamp threshold

Input quiescent current

V_VLIM

Voltage on VLIM

1.49

1.52

2.4

2.8

3.8

3

1.55

V

Charger enabled, USB2.0 mode

Charger enabled, USB3.0 mode

Charger enable, programmable mode

Charger enabled, default mode

Disabled, EN = 0V

5

mA

µA

I_IN

SYS to IN reverse current

blocking

SYS = SW = 4.5V, V_IN= 0V,

monitor V_INleakage

0.01

0.2

µA

SYS Output

Minimum SYS regulation

voltage

SYS voltage at V_BATT≤ 3.4V,

SYSFB float

V_SYS

3.45

3.6

3.75

V

3.4V < V_BATT≤ 4.2V, SYSFB float,

BATT float

V_BATT+

0.2V

3.5

4.5

4.4

SYS regulation voltage

V_SYS

Programmed by SYSFB

4.08

V

SYS reference voltage

Battery Discharge

V_{SYS_REF}

1.135 1.152 1.170

BATT to SYS resistance

V_IN= 0V, I_SYS= 200mA, V_BATT= 4.2V

V_SYS> V_BATT- 800mV, V_BATT= 4.2V

SYS short

40

6.2

230

50

mΩ

A

5

7.4

BATT to SYS current limit

mA

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

ELECTRICAL CHARACTERISTICS (continued)

V_IN= 5.0V, T_A= 25°C, unless otherwise noted.

Parameters

Symbol Condition

Min

Typ

Max Units

Battery Charger Voltage Spec

V_BATT> V_RECH, I_CHG≤ I_BF,

SYSFB float

4.179

4.2

4.221

V

Terminal battery voltage

V_BATT

V_SYS

0.04 x

I_BF

-

V_SYS< 4.2V, programmed by SYSFB

SYSFB float

3.9

4.0

3.95

85

4.1

V

Recharge threshold at V_BATT

V_RECH

SYSFB programmed

3.85

4.05

Recharge hysteresis

mV

V

Trickle charge threshold

Trickle charger hysteresis

Battery Charger Current Spec

Trickle charge current

2.9

3

3.1

200

mV

I_TRICKLE

I_BF

10%

I_CC

mA

A

Termination charger current

I_BFmaximum limit

5%

10% 15%

150 200

2.475 2.75 3.025

1.26 1.4 1.54

0.405 0.450 0.495

R_ISET= 760Ω

R_ISET= 1.53kΩ

R_ISET= 4.6kΩ

Constant current mode

charge current

I_CC

A

ISET reference voltage

Battery UVLO

1.1

2.4

2.2

1.15

2.6

1.2

2.8

2.6

V

Rising

Falling

V

2.4

V

V_BATT

65mV

-

Idea diode regulation voltage

V_SYS

I_BATT

Supplement mode

mV

µA

BATT leakage current

__________ _____________

V_BATT= 4.2V, SYS float, V_IN= PGND

20

30

ACOK, CHGOK

__________ _____________

ACOK, CHGOK output low

voltage

__________ _____________

Sinking 5mA

270

0.1

350

0.5

mV

ACOK,CHGOK leakage

current

Connected to 3.3V

μA

Timer

Trickle charge time

Total charge time

C_TMR= 0.1µF, I_CHG= 1A

45

Min

6.5

Hour

Negative Temperature Coefficient (NTC) Control

NTC low temp rising

threshold

V_THL

R_NTC= NCP18XH103F, 0°C

63

32

65

35

67

35

%V_CC

mV

Hysteresis on low temp

threshold

NTC high temp falling

threshold

V_THH

R_NTC= NCP18XH103F, 50°C

33.5

70

%V_CC

mV

Hysteresis on high temp

threshold

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

ELECTRICAL CHARACTERISTICS (continued)

V_IN= 5.0V, T_A= 25C, unless otherwise noted.

Parameters

VCC Supply

Symbol Condition

Min

Typ

Max Units

Rising

Falling

3.15

2.8

3.35

3

3.55

3.2

V

VCC UVLO

VCC output voltage

VCC output current limit

Logic

0mA < I_VCC< 25mA, V_IN= 6V

4.3

4.5

40

4.6

V

mA

0.4

8

V

ENinput low voltage

ENinput high voltage

1.5

4

EN= 4V

μA

ENinput current

M0, M1

-0.5

1.5

-0.1

EN= 0V

Logic high

Logic low

V

0.4

Protection

Thermal limit temperature

Thermal shutdown

NOTE:

120

150

°C

5) A Schottky diode is required from SW to GND when Pout is higher than 10W and VIN is over 12V.

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL PERFORMANCE CHARACTERISTICS

V_IN= 5.0V, V_BATT= full range, default mode, I_INlimit = 2A, V_SYS= 4.4V, R6 and R7 are floating, I_CHG

= 2A, V_INclamp = 4.5V, L = 1.2 µH, T_A= +25°C, unless otherwise noted.

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

V_IN= 12V, V_BATT= full range, default mode, I_INlimit = 2A, V_SYS= 4.4V, R6 and R7 are floating, I_CHG

2A, V_INclamp = 4.71V, L = 2.2µH, T_A= +25°C, unless otherwise noted.

=

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

V_IN= 12V, V_BATT= full range, default mode, I_INlimit = 2A, V_SYS= 4.4V, R6 and R7 are floating, I_CHG

2A, V_INclamp = 4.71V, L = 2.2µH, T_A= +25°C, unless otherwise noted.

=

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

V_IN= 12V, V_BATT= full range, default mode, I_INlimit = 2A, V_SYS=4.4V, R6 and R7 are floating, I_CHG

2A, V_INClamp = 4.71V, L = 2.2µH, T_A= +25°C, unless otherwise noted.

=

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL PERFORMANCE CHARACTERISTICS (continued)

V_IN= 12V, V_BATT= full range, default mode, I_INlimit = 2A, V_SYS= 4.4V, R6 and R7 are floating, I_CHG

2A, V_INclamp = 4.71V, L = 2.2µH, T_A= +25°C, unless otherwise noted.

=

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

BLOCK DIAGRAM

BST

IN

HSG

SYSFB1

EAO

EA

3.6V

L

Converter

control

Max(A,B)

SW

SYS

VBATT+200mV

Driver

1

0

M

Input current

limit reference

selector

C

LSG

Iref

M

EAO

SYSFB

VBG

VREF

SYSFB

SYS

SYSFB

EA

ILIM

SYSFB1

VLIM

1.5V

mO

4 0

V_BATx 2

Charge

Pump

VIN

Ideal diode

regulation

VTH

SYS

Battery switch

current limit

BATT

EN

3.5 V coarse

LDO &

EN

3.0 V UVLO

CC/ CV linear

charger

BATTFB

VBG

VREF_CC

VCC

Bandgap

& Bias

VBG

EN

4.5 V LDO

Charger Control & Chip Logic

UVLO

.

V UVLO

3 8

VIN

ISET

CHGOK

ACOK

TMR

NTC

GND

Figure 1: Functional Block Diagram

Figure 2: Functional Block Diagram

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

control scheme to ensure that the average input

current remains below the level programmed

via ILIM or the logic inputs (M0 and M1). This

ensures compliance with the USB specifications

and prevents overloading the wall adapter.

OPERATION

The MP2617H is a switching charger IC with

integrated, smart, power path management for

powering the system and charging a single-cell

battery independently and simultaneously.

When the input voltage is higher than the

under-voltage lockout (UVLO) threshold and

The MP2617H includes an input DC/DC step-

down converter for a wide range of DC sources

and USB inputs. The MP26127H has a

precision average input current limit to make

maximum use of the allowable input power.

This feature allows for fast charging when the

charger is powered from a USB port and

ensures that the input current never exceeds

the input power specification. Additionally, the

input current limit threshold can be programmed

by the logic inputs or a resistor from ILIM to

ground.

280mV higher than the battery voltage, the

——————

input voltage OK signal is active ( ACOK

becomes low), and the DC/DC converter soft

starts. The input power is sufficient for

supplying the combination of the system load

and battery charger, and the input current limit

loop is not triggered. The converter output

voltage (V_SYS) is regulated.

If BATT is greater than 3.4V, V_SYSis

approximately 0.2V above the battery voltage to

minimize the power loss of the battery charger

during fast charging. If BATT is less than 3.4V,

V_SYSis fixed at 3.6V to power the system

immediately, even when a drained battery is

inserted to be charged (see Figure 2)_.

The MP2617H implements an on-chip 40mΩ

MOSFET, which works as a full-featured linear

charger with trickle charge, high-accuracy,

constant-current (CC) charge and constant-

voltage (CV) charge, charge termination, auto-

recharge, NTC monitor, built-in timer control,

charge status indication, and thermal protection.

The charge current can be programmed by an

external resistor connected from ISET to AGND.

The IC limits the charge current when the die

temperature exceeds thermal regulation

threshold.

The system voltage can also be regulated to

any value between 4.08V to 4.4V in the

MP2617H by using a resistor divider on SYSFB

(see R6 and R7 in Figure 10). If SYSFB is left

floating, the system program is invalid, and V_SYS

is regulated according to BATT voltage (see

Figure 2).

The 40mΩ MOSFET works as an ideal diode to

connect the battery to the system load when the

input power is not enough to power the system

load. When the input is removed, the 40mΩ

MOSFET is turned on, allowing the battery to

power up the system.

The converter adopts a fixed off-time control to

extend the duty cycle (close to 100%) when the

input of the converter is close to V_SYS.

4.4V

4.2V

With smart power path management, the

system load is satisfied first, and the remaining

current is used to charge the battery. The

MP2617H reduces the charging current or uses

power from the battery to satisfy the system

load when its demand is over the input power

capacity.

V_SYS

200mV

3.6V

V_BATT

DC/DC Step-Down Converter

The DC/DC converter is a 1.6MHz, step-down,

switching regulator to provide input power to

SYS, which drives the combination of the

system load and battery charger. The regulator

contains an input current measurement and

3.4V

4.2V

Figure 3: SYS Regulation Output

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

At near-100% duty operation, the BST refresh

2. Input-Voltage Limit: A resistor divider from

IN to VLIM to AGND is used for input

voltage limit control. When the voltage on

VLIM reaches the 1.52V reference voltage,

the output of the input voltage limit error

amplifier drops to control the operation duty.

In this mode, the input voltage is clamped

according to the value set by the resistor

divider. The control to the system voltage

and charge current is the same as the input

current limit control. The charge current

drops down to satisfy the system current

request first. This feature provides a second

protection to the input power and ensures

safe operation of the input adapter. Even if

the wrong adapter is inserted, the MP2617H

can continue operating, providing the

maximum power to its load. The input

voltage limit value can be programmed

through the resistor divider from IN to VLIM

to AGND.

operation ensures that the driver voltage of the

high-side MOSFET (HS-FET) is charged by

turning on the low-side MOSFET (LS-FET) until

the negative inductor current (I_L) reaches a

threshold.

If the input power is insufficient for supplying

the combination of the system load and battery

charger, the DC/DC converter limits the total

power requirement by restricting the input

voltage, input current, and peak current through

the MOSFET. The power path management

reduces the charge current to satisfy the

external system load first. According to this

feature, the USB specification is always

satisfied first, even if the charge current is set

higher than the USB input current limit, and the

real charge current is reduced as needed.

Input Limit State

If the input power is insufficient for supplying

the combination of the system load and battery

charger, the MP2617H implements three input

limit control loops to reduce the charge current

and satisfy the external system load first. The

input in this case might be limited with either

input current limit, input voltage limit, or DC/DC

peak current limit.

3. Peak-Current Limit: The peak current of the

high-side switch of the DC/DC converter is

sensed during every cycle and is compared

to the 4.8A reference. If the peak current

reaches the threshold, peak-current limit

mode is triggered. The control of the charge

current is the same as the input current limit

and input voltage limit.

1. Input-Current Limit: When the input current

is higher than the programmed input current

limit, the input current limit loop takes the

control of the converter and regulates the

input current at a constant value. If the

battery voltage is over 3.4V, the output

voltage (V_SYS) drops down according to the

increase of the system current, and the

charge current drops down after the BATT-

to-SYS switch (40mΩ MOSFET) is fully on

according to V_SYSdropping down. During

this process, the system voltage is slightly

higher than V_BATT. If the battery voltage is

lower than 3.4V, to maintain the minimum

system voltage and ensure system

operation, the input current limit control pulls

down the charge current directly o reduce

the load of the converter so the system

current is satisfied first.

Input Current Limit Setting

The ILIM current is a precise fraction of the

adapter input current. When a programming

resistor is connected from ILIM to AGND, the

voltage on ILIM represents the average input

current of the pulse-width modulation (PWM)

converter. The input current approaches the

programmed limit, and the ILIM voltage reaches

1.14V.

The average input current limit can be set

through the resistor connected from ILIM to

AGND according to Equation (1):

40000

(1)

I_{IN_LIM}=1.14

(mA)

R_ILIM(kΩ)

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16

MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

When connected to a USB power source, the

battery is unresponsive. When the battery

voltage is above 3.0V, the charger operates in

constant-current mode. The current delivered to

the battery attempts to reach the value

programmed by ISET. Depending on the

available input power and system load

conditions, the battery charger may or may not

be able to charge at the fully programmed rate.

The system load is always satisfied first over

the battery charge current. If the system load

requirement is low, the battery can be charged

at a fully constant current.

input current limit is set internally, and the

programmed value is invalid. The MP2617H

provides a typical 450mA input current limit for

USB2.0 specification, and a typical 825mA

current limit for USB3.0 specification.

The input current limit can be set through the

two logic pins (M0 and M1) according to its

input specification (see Table 1). Both M0 and

M1 are pulled to logic high when floating. Under

this condition, the input current is limited to a

default value of 2A.

When the battery voltage reaches the battery

full threshold, the charger enters constant-

voltage mode operation.

Table 1: Input Current Limit Setting by M0 and

M1

M0

Low

High

M1

Low

High

Low

Mode

End of Charge (EOC) and Indication

USB2.0 mode

USB3.0 mode

Programmable mode

Default mode

In constant-voltage charge mode, the battery

voltage is regulated at 4.2V when SYSFB is

floating or SYS is programmed higher than the

battery-full threshold, and the charge current

decreases naturally. Once the charge current

reaches the battery full threshold (I_BF, 1/10 the

programmed charge current), the battery is fully

charged, and charge cycle is terminated.

High/float High/float

Input Voltage Limit Setting

The input voltage can be limited at a value set

by a resistor divider from IN to VLIM to AGND

according to the Equation (2):

If the charge current drops below I_BFbecause of

any limit condition, the MP2617H exits CV

mode, and the charge-full detection is invalid.

R1+R2

V

_{IN_LIM}=1.52

(V)

(2)

R2

When the voltage on VLIM drops and reaches

the 1.52V reference voltage, the input voltage is

clamped to the setting value.

A safe timer starts at the beginning of each new

charge cycle and monitors whether the entire

charge period is within the programmed time

limit. After each charge cycle, when the battery

is indicated as full, the timer counter resets. If

the time expires while the charging is still

Battery Charger

The MP2617H’s complete charge operation

consists of trickle charge, automatic charge

termination, charge status indication, timer

control, NTC indication, automatic recharge,

and thermal limiting.

ongoing, the timer forces the MP2617H to

_____________

terminate charging. CHGOK blinks to indicate

the fault condition.

When the PWM converter exits soft start, the

battery charge cycle begins. The MP2617H first

determines if the battery is deeply discharged. If

the battery voltage is lower than the trickle

charge threshold (typically 3.0V), the battery

charger starts in trickle charge mode. The

trickle charge current is limited to 10% of the

programmed charge current until the battery

voltage reaches 3.0V. If the charge remains in

trickle charge mode for longer than “trickle

charge timer period”, the timer out condition is

If system voltage is programmed below 4.2V by

the resistor divider at SYSFB, the battery is

charged close to V_SYSuntil the charge current

reaches the I_BFthreshold.

Automatic Recharge

Once the battery charge cycle is completed, the

MP2617H turns off, indicating the battery-full

status. During this process, the battery power

may be consumed by the system load or self-

discharge. If the input power is always on, to

ensure that the battery is not exhausted, the

new charge cycle begins automatically when

triggered, the charge is terminated, and

_____________

CHGOK starts blinking to indicate that the

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

the battery voltage falls below the auto-

ISET can be also used to control the operation

of the charger. Floating ISET disables the

charger function, while the output of the PWM

converter continues to supply power to the

system. Conversely, a resistor from ISET to

AGND enables charging at the programmed

charge current.

recharge threshold (V_RCHG) when SYSFB is

floating, or V_RCHGminus 50mV if SYSFB is not

floating and connected to a resistor divider. The

timer restarts when the auto-recharge cycle

begins.

During the charge-off state when the battery is

fully charged, if the input power is recycled, or

the EN signal is refreshed, the charge cycle

restarts, and the timer refreshes, even if the

battery voltage is above the auto-recharge

threshold.

The logic control of the ISET pin of the

MP2617H can be set as shown in Figure 3. In

this way, logic low can be set as the off signal,

and logic high can be set as the on signal with

an N-channel MOSFET.

Charge Current Setting

ISET

The charge current of the MP2617H is

programmed using a single resistor from ISET

to ground. The program resistor and charge

current can be calculated with Equation (3):

OFF ON

R_ISET

1800

(3)

I_CHG 1.15

(mA)

Figure 3: ISET Logic Control

R_SET(k)

__________

Input Power Status Indication (ACOK)

In either constant-current mode or constant-

voltage mode, the ISET voltage is proportional

to the actual charge current delivered to the

battery (I_BATT). The charge current can be

calculated by monitoring the ISET voltage with

Equation (4):

An internal UVLO circuit monitors the input

voltage and keeps the IC in its off state until the

input rises over the rising threshold (3.8V).

When the input voltage decreases below the

lower threshold (3.5V), the IC turns off, and the

system load is powered by the battery

__________

V

^ISET×I_CHG

(4)

automatically. ACOK is an open-drain, active-

low output that indicates the status of the input

power. The input is considered valid when the

input voltage is over the UVLO rising threshold

and 280mV higher than the battery voltage to

ensure that both the converter and the charger

can operate normally. If the input voltage from

I_BATT

=

1.15

Additionally, the actual battery charge current

may be lower than the programmed current due

to the limited input power available and

prioritization of the system load.

an adapter or a USB port is indicated as OK,

The battery charge full-current threshold (I_BF) is

set internally at 10% of the programmed charge

current. However, I_BFhas a 150mA maximum

limit which cannot be exceeded.

__________

ACOK turns low.

_____

During EN off or thermal shutdown conditions,

__________

Logic Control

ACOK turns high to indicate that no power is

__________

The MP2617H has two separate enable control

provided by the input to the system. The ACOK

signal indicates whether the input is supplying

_____

pins. EN is a logic control pin that controls the

_____

power to the system load or not. Any other

operation of the entire IC. When EN is low, the

__________

condition cannot affect the ACOK indication as

long as the input power is present.

IC is enabled, and the PWM converter output

_____

powers the system and the charger. When EN

is high, both the PWM converter and the

charger are disabled. The BATT-to-SYS switch

fully turns on to connect the battery to power

the system.

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18

MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

_____________

The total charge time can be calculated with

Equation (6):

Charge Status Indication (CHGOK)

_____________

CHGOK is an open-drain, active-low output that

C_TMR

_____________

(I

(hr)

CHG

1A) (6)

t_{Total_TMR} 6.5

indicates the status of the charge. CHGOK is

0.1μF

low during normal charging operation and turns

_____________

Equation (5) and Equation (6) are based on a

1A charge current. As a result of the power path

management control, the charge current might

vary during normal operation. Under this

condition, the MP2617H takes this variation into

account automatically and adjusts the timer

period accordingly.

high after the charge is full. CHGOK blinks if a

fault condition occurs, including an NTC fault

(battery temperature is invalid) and timer out

(bad battery).

_____________

In the event of a fault condition, CHGOK

switches at 6Hz with a 50% duty cycle and

enters blinking mode. Check the application

circuit to find the root cause of the fault

When the charge current is higher than 1A, the

safe timer period is reduced accordingly with

the same TMR capacitor. If the charge current

is reduced because of insufficient input power,

the timer period is increased proportionally with

the same rate at which the charge current is

reduced.

condition if the blinking signal is asserted.

_____________

For no-battery conditions, CHGOK blinks

according to the transition between charging

and charge full. The blinking frequency is

determined by the charge and discharge cycle

of the output capacitor.

If the charge current reduces to 0 due to a high

system load, the timer is suspended temporarily.

This feature prevents falsely tripping the timer

and indicating a bad battery when there is little

charge current delivered to the battery as a

result of insufficient input power. When a timer-

If the charge current to the battery is low or if

the battery is in supplement mode caused by

_____________

insufficient input power, CHGOK remains low to

avoid providing a false charge-full indication.

__________

_____________

out condition occurs, the MP2617H terminates

Table 2 shows the ACOKand CHGOK status

under different charge conditions.

_____________

the charge immediately, and CHGOK blinks to

indicate the fault status. The timer is refreshed

Table 2: Charger Status Indication

__________

_____________

and the MP2617H restarts the charge cycle if

Charger Status

_____

ACOK

CHGOK

the input starts up again, the EN or ISET signal

is refreshed, or auto-recharge occurs.

In charging, supplement

mode

End of charge, ISET

disable charger only

Low

NTC Thermistor

High

NTC allows the MP2617H to sense the battery

Blinking at

6Hz

temperature using

a

negative thermal

NTC fault, timer out

coefficient (NTC) thermistor, usually available in

the battery pack to ensure a safe operating

environment for the battery. Connect a resistor

with an appropriate value from VCC to NTC and

the NTC resistor from NTC to AGND. The

voltage on NTC is determined by the resistor

divider whose divide ratio as the different

resistance of the NTC thermistor depends on

the ambient temperature of the battery.

_____

V_INabsent, EN disable,

thermal shutdown

High

Timer Setting

The MP2617H uses an internal timer to

terminate the charge if the timer times out. The

timer duration is programmed by an external

capacitor at TMR and related to the real charge

current.

The MP2617H has an internal NTC voltage

comparator to set the upper and lower limit of

the divide ratio. If the NTC voltage falls out of

this range, then the temperature is outside of

the safe operating range. As a result, the

The trickle-mode charge time can be calculated

with Equation (5):

C_TMR

(I

(min)

CHG

1A) (5)

t_{Trickle _ TMR} 45

0.1μF

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

MP2617H stops charging and reports this on

Battery Discharge Protection

the indication pins. Charging resumes

automatically after the temperature falls back

into the safe range.

When the input power is removed or invalid, the

system load draws power from the battery via

the battery switch. Under this condition, the

battery switch is fully on to minimize power loss.

The MP2617H integrates battery discharge

protection. If the battery discharge current is

larger than the discharge current limit threshold

(I_DIS, 6.2A), the current is regulated at the pre-

set limited value. If the current increases further,

the SYS voltage starts to decrease. When V_SYS

drops to about 800mV below V_BATT, a SYS short

condition is detected. Under this condition, the

discharge current is limited at 230mA. In the

event of a short from the system to GND, the

discharge current from the battery to the system

is also limited to 230mA.

Thermal Protection

The MP2617H implements thermal protection to

prevent thermal damage to the IC or

surrounding components. An internal thermal

sense and feedback loop decrease the charge

current automatically when the die temperature

rises to about 120°C. This function is referred to

as the charge current thermal fold-back. This

feature protects the MP2617H from excessive

temperature due to high-power operation or

high ambient thermal conditions. Another

benefit of this feature is that the charge current

can be set according to the requirement rather

than the worst-case condition for a given

application with the assurance of safe operation.

The MP2617H stops charging if the junction

temperature rises above 150°C as the IC enters

thermal shutdown protection.

The battery voltage UVLO is always monitored.

If the battery voltage is lower than the battery

UVLO threshold, the battery switch is turned off

immediately. This feature prevents the battery

from being over-discharged.

Ideal Diode Mode

Dynamic Power Path Management (DPPM)

If the system current requirement increases

such that the pre-set input current limit of the

PWM converter is reached and the charge

current has reduced to zero, the additional

current will be drawn from the battery via the

BATT-to-SYS switch. To avoid very large

currents from being drawn from the battery

which might affect the reliability of the device,

the MP2617H controls the battery MOSFET to

work in the ideal diode mode. When V_SYSdrops

to 40mV lower than V_BATT, then the MP2617H

will enter ideal diode mode and regulate V_SYSto

V_BATT- 65mV. After the system load decreases

and V_SYSis 40mV higher than V_BATT, the battery

MOSFET exits ideal diode mode, and the

charge cycle restarts softly.

In the presence of a valid input source, the

PWM converter supplies current to both the

system and the battery charger.

The voltage (V_SYS) is regulated based on the

value of the battery voltage. When V_BATTis

higher than 3.4V, V_SYSis regulated 200mV

above V_BATTto charge the battery. When V_BATT

is lower than 3.4V, V_SYSis regulated at a

constant 3.6V to ensure that the system can still

be powered up, even with a drained battery

connected.

When the input source is overloaded, either the

current exceeds the input current limit or the

voltage falls below the input voltage limit. The

MP2617H then reduces the charge current until

the input current falls below the input current

limit and the input voltage rises above the input

voltage limit. If the system current increases

beyond the power allowed by the input source,

additional power is drawn from the battery via

an on-chip 40mΩ MOSFET working as an ideal

diode. If the system current increased further,

when the discharge current times the Ron is

over 65mV, the V_SYScan not be regulated, the

BATT to SYS MOSFET just turned fully on, the

battery powers the system together with the

converter from VIN as the supplement mode.

V_BATT-40mV

Enable Ideal Diode Mode

V_SYS

Disable Ideal Diode Mode

V_BATT+40mV

Figure 4: Ideal Diode Mode Enable/Disable

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Operation Flow Chart

Additionally, if the input source is removed, the

Figure 5 shows the operation flow chart of the

MP2617H. Figure 6 shows the operation

process.

MP2617H turns on the 40mΩ MOSFET,

allowing the battery to power the system load to

maintain the operation of the portable device.

POR

Chip Enable?

No

Yes

V_IN>3.0V?

No，

POR="1"

Yes,

POR="0"

Enable BG

Yes

Battery power system

Enable discharge limit

V_BATT>V_{BATT_UVLO}

?

BGOK="0"

BGOK="1"

No

Enable VREF LDO

V_IN>V_{IN_UVLO}(V_TH)?

System shuts down

No power to system

No,

UVLO="1"

Yes,

UVLO="0"

V_IN>V_BATT+280mV?

Yes

Enable DC-DC

DC-DC soft starts

V_{SYS_REF}=max(V_BATT

+

200mV,3.6V

V_SYS>V_BATT

ISET OK?

?

No

Yes

Battery power

system switch

turns off

DC-DC starts ready?

No

Yes

Enable Battery

Charger

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Yes

Clamp DC-DC

EAOto regulate

the part

Any Limit condition

triggered?

at the limit state

No

V_BATT<3.4V?

V_BATT>3.0V?

Yes

No

Yes

No

Trickle Charge

I_CHG=10%I_CC

V_SYSdrops down,

Charge switch

is fully on

Decrease I_CHG

Keep V_SYS=3.6V

,

CC/CV Charge

Yes

No

Satisfy System current

Charge the battery with

remaining current

No

Limit condition

Removed?

I_CHG=I_BF

?

No

Yes

Disable

Ideal Diode Mode

Charge in

CV mode and

I_CHG<I_BF?

No

Charge Full, EOC=1

TMR off,

Yes

I_CHG=0?

Yes

clear the counter

DC-DC keeps work

Yes

No

V_SYS>V_BATT+40mV?

V_SYS<V_BATT-40mV?

Yes

V_SYS<V_BATT-40mV?

No

Yes

V_BATT>V_{BATT_UVLO}

?

No

Yes

V_BATT<V_RCHG

?

Ideal Diode Mode:

V_SYS=V_BATT-65mV,

Enable discharge

current limit

Battery switch shuts down,

DC-DC in over load

condition,

V_SYSdrops down

Figure 5: MP2617H Operation Flow Chart under No Fault Condition

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Normal

operation

voltage

UVLO

Threshold-Hys

UVLO

Thresohold

V_IN

0

Power Path Management

Battery

Supplement

Mode

I_SYS

0

CV Charge

CC Charge

Trickle Charge

Battery

Full

I_BATT

0

I_SYS-I_{IN_LIM}

Input Power

Current Limit

I_{IN_LIM}

I_{IN_AVE}

0

Supplement

Mode-

Discharging

Auto-

Recharging

Self-

discharging

Power off-

discharging

Charging

V

_BATT=4.0V

V_SYS

V_BATT

V_BATT=3.4V

V

_BATT=3.0V

0

Figure 6: MP2617H Operation Process under No Fault Condition

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

example, if the typical I_CHGis designed as 2A,

APPLICATION INFORMATION

Setting the Input Current Limit

then the R_SETis calculated at 1.05kΩ. The

tolerance of the I_CHGsetting is ±10%. If the

minimum or maximum charge current is

required, first the typical value should be

calculated according to the tolerance. After that,

calculate the resistor according to formula (3).

1% accuracy resistor is used for this setting.

First the input current limit can be set by the M0

and M1 pins refer to the Table 1, the exact

current value in minimum, typical and maximum

is listed in the EC table.

Under program mode, connect a resistor (R_ILIM

)

from ILIM to AGND to program the input current

limit for different input ports. The relationship

between the input current limit and resistor

value is as the following formula from Equation

(1):

For a given setting resistor, the charge current

can be calculated by the same way did in the

input current limit setting. Usually in USB mode,

the charge current is always set over the USB

input limit specification. Then the MP2617H

regulates the input current constant at the

limitation value. Therefore, the real CC charge

current is not the setting value and varies with

different input and battery voltages.

40000

(1)

I_{IN_LIM}=1.14

(mA)

R_ILIM(kΩ)

The tolerance is ±8% of the input current limit

setting.

The maximum CC charge value can be

calculated with Equation (7):

So for a required minimum input current limit

value, just calculate its typical value first, then

calculate the setting resistor based on Equation

(1). Also the maximum value can be calculated

V I_ILIM

IN

(7)

I_{CC _ MAX}



(A)

V_TC

according to the tolerance.

resistor is used for this setting.

1% accuracy

Where V_TCis the trickle charge threshold (3V),

and η is the current charge efficiency. If V_INis

5.5V, I_ILIMis 1.5A, η is 83%, then I_{CC_MAX}is

2.28A.

Also, for a given resistor of R_ILIM, the input

current limit can be calculated. Following table

is an example:

Figure 7 shows a calculating charge current

curve by limiting the input current limit based on

the MP2617H.

Table 3: Example of R_ILIMsetting

R_ILIM

I_{IN_LIM}

Resistor

8%

-8%

(kΩ)

(mA)

Typ.

Min.

Max.

54.9

830.601 897.049 764.153

906.11 771.872

55.449 822.377 888.168 756.587

3A

54.351 838.991

I_{CC_MAX}

2A

1A

Therefore, if customer selected a 54.9k in 1%

accuracy resistor for the input current limit

setting, then the typical input current limit value

is 830.6mA, the minimum is 756.6mA and the

maximum is 906mA.

Setting the Charge Current

3V

4.2V

A resistor (R_ISET) connected from ISET to AGND

sets the charge current (ICHG). The relationship

between the charge current and setting resistor

is shown in Equation (3):

Battery Voltage

Figure 7: I_CHGVariation with Different Input

Current Limit

Setting the Input Voltage Limit

1800

I_CHG 1.15

(mA)

(3)

The input clamp voltage is set using a resistive

voltage divider from the input voltage to VLIM

pin. The voltage divider divides the input

voltage down to the limit voltage with the ratio in

Equation (8):

R_SET(k)

For example, if the typical I_CHGis designed as

2A, then the R_SETis calculated at 1.05kΩ. For

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Be noted that, the minimum V_SYSis limited to be

higher than the maximum value of the auto-

recharge threshold, which is 4.05V.

R2

(8)

V_VLIM= V

×

(V)

IN_LIM

R1+R2

The input voltage can be calculated with

Equation (10):

Selecting the Inductor

Inductor selection trades off among cost, size,

and efficiency. A lower inductance value

corresponds to a smaller size, but results in

higher ripple currents, higher magnetic

R1+R2

(9)

V

_{IN_LIM}= V_VLIM

×

(V)

R2

The voltage clamp reference voltage (V_VLIM) is

1.52V, and R2 is typically 10kΩ. With this value,

calculate R1 with Equation (11):

hysteretic

losses,

and

higher

output

capacitances. From a practical standpoint, the

inductor ripple current does not exceed 30% of

the maximum load current under worst cases

conditions. For example, if the I_CHGis setting to

3A in MP2617H, then, ΔI_Lis general set at 0.9A.

V

_{IN_LIM}- V

(10)

R1=R2×

^VLIM(V)

V_VLIM

For example, for a 4.65V input limit voltage, R2

is 10kΩ, and R1 is 20.6kΩ.

However, for the light load condition, the

inductor ripple current will be very small which

may cause unstable operation due to the peak

current mode control of the IC. For stable

operation, the experienced minimum limit value

for inductor current ripple is 0.5A. Therefore, the

inductor current ripple is the maximum one of

30% times I_CHGand 0.5A.

The minimum value and the maximum value of

the input voltage limit can be calculated

according to the accuracy of the resistor and

the tolerance of V_VLIM. 1% accuracy resistors

are used for R1 and R2.

Setting the System Voltage

And the inductance can be calculated according

to Equation (13):

The system voltage can be regulated to any

value between 4.08V to 4.4V by the resistor

divider on SYSFB, shown as R6 and R7 in

Figure 10. Calculate V_SYSwith Equation (11):

V  V_BATT

I_{L _MAX}V  f_S(MHz)

V_BATT

IN

L 

(µH) (13)

IN

R6  R7

The peak current of the inductor is calculated

as Equation (14):

(11)

V_SYS V_{SYS_REF}



R7

Where V_{SYS_REF}is the reference voltage of SYS

(1.152V). With a typical value for R7 (10kΩ), R6

can be determined with Equation (12):

%ripple

I_PEAK I_LOAD(MAX)(1

)

(mA) (14)

2

Where VIN, VSYS, and fS are the input voltage,

the SYS output voltage, and the switching

frequency, respectively.

V_SYS V

^SYS_REF(V)

(12)

R6  R7

V_{SYS_REF}

Following Table 4 provides the selection guide

of the inductance based on different input

voltage.

For example, for a 4.2V system voltage, R7 is

10kΩ, and R6 is 26.5kΩ. 1% resistors are

selected for the R5 and R6.

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Table 4: Inductance Selection Guide under different Input Voltage

SPEC

V_IN

Inductance Selection

L_MIN

(uH)

L_MAX

L

Saturation

DCR

Package

(uH) (uH) Current (A)⁽⁶⁾(mΩ)

V  V_SYS

V_SYS

IN

L 

Application

Required

Application

Required

Application

Required

5V

9V

0.367 1.25

1.0

2.2

>3.95

>6⁽⁷⁾

<50

I_L

V  f_S(MHz)

IN

ΔI_L=max (0.3*I_CHG,0.5A)

ΔI_LMIN=0.5A

1.5

2.8

3.5

ΔI_LMAX=0.9A

12V

1.75

For the condition that VIN is higher or equal to

12V, and the total output power including

system load and battery charging is over 10W,

an 1A schottky diode from SW to GND is

required. The voltage rating of the schottky

diode is usually selected at 30V.

Selecting the Output Capacitor

The output capacitor (C_SYS) from the typical

application circuit is parallel with the SYS load.

C_SYSabsorbs the high-frequency switching

ripple current and smoothes the output voltage.

Its impedance must be much less than that of

the system load to ensure that it absorbs the

ripple current properly.

Selecting the Input Capacitor

The input capacitor (C_IN) from the typical

application circuit absorbs the maximum ripple

current from the PWM converter, which is given

by Equation (15):

Ceramic capacitors are recommended for their

lower ESR and smaller size, which allows the

ESR of the output capacitor to be ignored. The

output voltage ripple can be calculated with

Equation (16):

V_{SYS_MIN}(V_{IN_MAX} V_{SYS_MIN}

)

(15)

I_{RMS_MAX} I_{CC_MAX}



V

IN_MAX

V_SYS

1

V_SYS

V_SYS

V

IN

For I_{CC_MAX}= 3A, V_{SYS_MIN}= 3.6V, V_{IN_MAX}= 14V,

the maximum ripple current is 1.3A. Select the

input capacitors so that the temperature rise

caused by the ripple current does not exceed

10°C. Ceramic capacitors with X5R or X7R

dielectrics are recommended because of their

low ESR and small temperature coefficients.

For most applications, use a 10µF capacitor.

When input voltage is over 10V, 22uF capacitor

is used for C_IN.

(16)

r 



%

2

8C2 f_SL

To guarantee ±0.5% system voltage accuracy,

the maximum output voltage ripple must not

exceed 0.5% (e.g.: 0.1%). The maximum output

voltage ripple occurs at the minimum system

voltage and the maximum input voltage.

The output capacitor can be calculated with

Equation (17):

V_{SYS _MIN}

Besides, usually a small cap with at least 1uF

(C1) from IN to GND is required to be put as

much close as possible to the IC.

1

V

IN

(17)

C_SYS



2

8 f_SL r

For the input voltage is high to 14V, consider

the spike when input insert, select the input

capacitors (both the 22uF and 1uF) in 25V

rating.

When SYSFB pin is floating, output voltage

ripple is the main concern to select the output

capacitor (C_SYS), refer to Table 5 for detail

selection guide about the SYS capacitance

selection under typical inputs.

NOTE:

6) Saturation Current of the inductor should be higher than the IPEAK, add 0.5A margin here.

7) This requirement is for SYS short protection consideration. It could be >3.95A as usual if this feature is not included in the

application.

MP2617H Rev. 1.03

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26

MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

Table 5: SYS Capacitance Selection Guide

SPEC

V_IN

SYS Capacitance (C_SYS) Selection

C_{SYS_MIN}(uF) ⁸⁾

When SYSFB is

Floating

C_{SYS_MIN}(uF) ⁸⁾

When SYSFB is Characteristic

Programmed

Temperature

Package

V_SYS

1

V

IN

C_SYS



2

8 f_SL r

5V

Application

Required

13.6

13.3

15.5

20

X5R;X7R

Δr=0.1%

9V

Application

Required

L=1uH @V_IN=5V

L=2.2uH @V_IN=9V

L=2.2uH @V_IN=12V

12V

Application

Required

When SYSFB is programmed using external

resistors, the control loop function is changed.

A zero point is added around the cross over

frequency of the DC gain, and this may result in

the phase margin varied a lot, which may cause

the unstable operation. To avoid this condition,

a minimum capacitance requirement should be

satisfied to make the pole point to compensate

the zero point. This minimum capacitance is

20uF for a general application.

For a given NTC thermistor, set the NTC

window by selecting appropriate R_T1and R_T2

values with Equation (18) and Equation (19):

R_T2//R_{NTC_Cold}

R_T1R_T2//R_{NTC_Cold}VCC

V_THL

(18)



R_T2//R_{NTC_Hot}

R_T1R_T2//R_{NTC_Hot}VCC

V_THH

(19)



Where R_{NTC_Hot}is the value of the NTC resistor

at the high end of the required temperature

operation range, and R_{NTC_Cold}is NTC resistor

value at a low temperature. The two resistors

(R_T1and R_T2) allow the high temperature limit

and low temperature limit to be programmed

independently. With this feature, the MP2617H

can fit most NTC resistor types and different

temperature operation range requirements.

The R_T1and R_T2values depend on the type of

NTC resistor used. For example, for the

thermistor NCP18XH103, R_{NTC_Cold}is 27.445kΩ

at 0°C, and R_{NTC_Hot}is 4.1601kΩ at 50°C.

So, for the SYSFB programmed condition, the

C_SYSshould be selected as max (C_{SYS_MIN}

,

20uF), C_{SYS_MIN}is calculated from the formula of

equation (17), as shown in Table 5. For better

stability margin, select

a

47uF ceramic

capacitor with 6.3V and above voltage rating as

the output capacitor in this case.

Selecting a Resistor for the NTC Sensor

Figure 8 shows an internal resistor divider

reference circuit to limit the low temperature

threshold and high temperature threshold at

V_THHand V_THL, respectively.

Equation (18) and Equation (19) can be used to

calculate R_T1= 7.15kΩ and R_T2= 25.5kΩ,

assuming that the NTC window is between 0°C

V_THH

V_THL

and 50°C and using the

from the EC table.

and

values

VCC

Figure 8: NTC Function Block

NOTE:

8) For different voltage rating, capacitance will have different DC bias characteristic. Suppose a general condition, capacitance drops

40% under VSYS=4.4V under 10V rating, and 50% at 6.3V rating.

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

PCB Layout Guidelines

Efficient PCB layout is critical for specified

noise, efficiency, and stability requirements. For

best performance, follow the guidelines below.

1) Route the power stage adjacent to its

ground.

2) Minimize the high-side switching node (SW,

inductor) trace lengths in the high-current

paths and the current sense resistor trace.

3) Keep the switching node short and away

from all small control signals, especially the

feedback network.

4) Place the input capacitor as close to IN and

PGND as possible.

5) Place the output inductor close to the IC.

6) Connect the output capacitor between the

inductor and PGND of the IC.

7) Connect the balls for the power pads (IN,

SW, SYS, BATT, and PGND) to as much

copper on the board as possible for high-

current applications.

This

improves

thermal

performance

because the board conducts heat away

from the IC.

8) Connect the PCB ground planes directly to

the return of all components through vias.

9) Place vias inside the PGND pads for the IC

if possible.

A star ground design approach is used to keep

circuit block currents isolated (high-power/low-

power small signal), which reduces noise-

coupling and ground-bounce issues. A single

ground plane with a small layout produces no

ground bounce issues, and segregating the

components minimizes coupling between

signals.

MP2617H Rev. 1.03

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL APPLICATION CIRCUITS

ON

OFF

VILIM

M0

M1

EN

5V Input

L

SYS Load

SW

IN

1.0uH

2k

R3

R4

C1

1uF

C3

100nF

CHGOK

C_SYS

BST

SYS

R1

21k

ACOK

VCC

22uF

MP2617H

SYSFB

PGND

R_T1

C_IN

10k

NTC

10uF

C2

R2

I_CHG

10k

BATT

R_T2

10k

1uF

vBATT

TMR

AGND

C_BATT

C_TMR

100nF

ISET

ILIM

22uF

R_ISET

1.05k

R_ILIM

30.9k

0

Figure 9: Typical Charge Application Circuit for 5V input

Table 6: The Key BOM of Figure 9.

Qty

Ref

Value

Description

Package Manufacture

Ceramic Capacitor;10V;

X5R or X7R

1

C_IN

C1

10μF

1206

0603

Any

Ceramic Capacitor;10V;

X5R or X7R

1

1μF

Any

Ceramic Capacitor;6.3V;

X5R or X7R

C2

1uF

0603

Ceramic Capacitor;16V;

X5R or X7R

Ceramic Capacitor;6.3V;

X5R or X7R

1

C3

100nF

0603

Any

C_TMR

Ceramic Capacitor;10V;

X5R or X7R

2

1

C_SYS,C_BATT

R_T1,R_T2

L1

22uF

10k

1206

0603

SMD

Any

Film Resistor;1%

Inductor;1.0uH;Low

DCR;I_SAT>3.95A

1.0μH

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

TYPICAL APPLICATION CIRCUITS

ON

OFF

R5 100k

VILIM

M0

M1

EN

12V Input

L

SYS Load

SW

IN

2.2uH

D1

C3

2k

R3

R4

C1

1uF

BST

SYS

CHGOK

C_SYS

100nF

R1

21k

ACOK

VCC

22uF

C4

R6

26.5k

R7

4.7uF

MP2617H

SYSFB

PGND

R_T1

C_IN

10k

NTC

22uF

R2

C2

I_CHG

10k

BATT

R_T2

10k

1uF

vBATT

TMR

AGND

C_BATT

22uF

C_TMR

100nF

ISET

ILIM

R_ISET

1.05k

R_ILIM

15.4k

0

Figure 10: Typical Charge Application Circuit for 12V Input and 3A Total System Load

Table 7: The Key BOM of Figure 10.

Qty

Ref

Value

Description

Package Manufacture

Ceramic Capacitor;25V;

X5R or X7R

1

C_IN

22μF

1206

0603

Any

Ceramic Capacitor;25V;

X5R or X7R

1

C1

C2

1μF

Ceramic Capacitor;

6.3V; X5R or X7R

1uF

0603

Any

Ceramic Capacitor;25V;

X5R or X7R

Ceramic Capacitor;10V;

X5R or X7R

Ceramic Capacitor;

6.3V;X5R or X7R

Ceramic Capacitor;10V;

X5R or X7R

1

2

C3

C4

100nF

4.7uF

100nF

22uF

0603

1206

Any

C_TMR

C_SYS,C_BATT

1

3

R6

26.5k

10k

Film Resistor;1%

0603

Any

R_T1,R_T2,R7

Inductor;2.2uH;Low

DCR;I_SAT>6A

1

L1

2.2μH

SMD

Any

D1

30V,1A 30V,1A,schottky diode

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MP2617H – SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

PACKAGE INFORMATION

QFN-20 (3mmx4mm)

PIN 1 ID

MARKING

PIN 1 ID

0.10 X 45° TYP

PIN 1 ID

INDEX AREA

TOP VIEW

BOTTOM VIEW

SIDE VIEW

0.10 X 45°

NOTE:

1) ALL DIMENSIONS ARE IN MILLIMETERS.

2) EXPOSED PADDLE SIZE DOES NOT INCLUDE

MOLD FLASH.

3) LEAD COPLANARITY SHALL BE 0.10

MILLIMETERS MAX.

4) JEDEC REFERENCE IS MO-220.

5) DRAWING IS NOT TO SCALE.

RECOMMENDED LAND PATTERN

NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third

party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not

assume any legal responsibility for any said applications.

MP2617H Rev. 1.03

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31


型号：	MP2617H
厂家：	MONOLITHIC POWER SYSTEMS
描述：	Wide input Voltage, 3A, Switching Charger With NVDC Power Path Management For Single Cell Li Battery 电池
文件：	总31页 (文件大小：1826K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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