EN23F0QI_技术文档

EN23F0QI

15A Voltage Mode Synchronous Buck PWM

DC-DC Converter with Integrated Inductor

Description

Features

The EN23F0QI is a Power System on a Chip

(PowerSoC) DC-DC converter. It integrates MOSFET

switches, small-signal control circuits, compensation

and an integrated inductor in an advanced

12x13x3mm QFN module. It offers high efficiency,

excellent line and load regulation. The EN23F0QI

operates over a wide input voltage range and is

specifically designed to meet the precise voltage and

fast transient requirements of high-performance

products. The EN23F0QI features frequency

synchronization to an external clock, power OK

output voltage monitor, programmable soft-start along

with thermal and over current protection. The device’s

advanced circuit design, ultra high switching

frequency and proprietary integrated inductor

technology delivers high-quality, ultra compact, non-

isolated DC-DC conversion.

•

Integrated Inductor, MOSFETs, Controller

Total Solution Size Estimate 308mm²

Wide Input Voltage Range: 4.5V – 14V

2% V_OUTAccuracy (Over Line/Load/Temperature)

Master/Slave Configuration for Parallel Operation

o Up to 4 Devices with 48A capability

Frequency Synchronization (External Clock)

Output Enable Pin and Power OK Signal

Programmable Soft-Start Time

•

Under Voltage Lockout Protection (UVLO)

Programmable Over Current Protection

Thermal Shutdown and Short Circuit Protection

RoHS compliant, MSL level 3, 260^oC reflow

Applications

The Enpirion solution significantly helps in system

design and productivity by offering greatly simplified

•

Space Constrained Applications

Distributed Power Architectures

board

design,

layout

and

manufacturing

Output Voltage Ripple Sensitive Applications

Beat Frequency Sensitive Applications

requirements. In addition, overall system level

reliability is improved given the small number of

components required with the Enpirion solution.

Servers, Embedded Computing Systems,

LAN/SAN Adapter Cards, RAID Storage Systems,

Industrial Automation, Test and Measurement,

and Telecommunications

All Enpirion products are RoHS compliant and lead-

free manufacturing environment compatible.

Efficiency vs. Output Current

100

90

80

70

60

50

40

CONDITIONS

V_IN= 12.0V

AVIN = 3.3V

Dual Supply

VOUT = 3.3V

VOUT = 1.8V

VOUT = 1.2V

30

20

10

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

OUTPUT CURRENT(A)

Figure 1. Simplified Applications Circuit

Figure 2. Highest Efficiency in Smallest Solution Size

(Footprint Optimized)

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EN23F0QI

Ordering Information

Part Number

EN23F0QI

EN23F0QI-E

Package Markings

EN23F0QI

Temp Rating (°C)

Package Description

92-pin (12mm x 13mm x 3mm) QFN T&R

QFN Evaluation Board

-40 to +85

EN23F0QI

Packing and Marking Information: http://www.enpirion.com/resource-center-packing-and-marking-information.htm

Pin Assignments (Top View)

Figure 3: Pin Out Diagram (Top View)

NOTE A: NC pins are not to be electrically connected to each other or to any external signal, ground, or voltage.

However, they must be soldered to the PCB. Failure to follow this guideline may result in part malfunction or damage.

NOTE B: Shaded area highlights exposed metal below the package that is not to be mechanically or electrically

connected to the PCB. Refer to Figure 14 for details.

NOTE C: White ‘dot’ on top left is pin 1 indicator on top of the device package.

Enpirion Confidential

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EN23F0QI

Pin Description

I/O Legend:

P=Power

G=Ground

NC=No Connect

I=Input O=Output

I/O=Input/Output

NAME I/O

FUNCTION

NO CONNECT – These pins may be internally connected. Do not connect them to each

1-24,

36, 81

NC

NC other or to any other electrical signal. Failure to follow this guideline may result in device

damage.

Regulated converter output. Connect these pins to the load and place output capacitor

between these pins and PGND pins 40-42.

25-35

VOUT

O

NO CONNECT – These pins are internally connected to the common switching node of the

NC(SW) NC internal MOSFETs. They are not to be electrically connected to any external signal, ground,

or voltage. Failure to follow this guideline may result in damage to the device.

37-39,

83-92

Input/Output power ground. Connect these pins to the ground electrode of the input and

40-46

47-63

PGND

PVIN

G

P

output filter capacitors. See VOUT and PVIN pin descriptions for more details.

Input power supply. Connect to input power supply. Decouple with input capacitor to PGND

pins 43-46.

Internal 3.3V linear regulator output. Connect this pin to AVIN (Pin 73) for applications

where operation from a single input voltage (PVIN) is required. If AVINO is being used,

place a 1µF, X5R/X7R, capacitor between AVINO and AGND as close as possible to

AVINO.

64

AVINO

O

65

66

PG

BTMP

I/O Place a 0.1µF, X7R, capacitor between this pin and BTMP.

I/O See pin 65 description.

Internal regulated voltage used for the internal control circuitry. Place a 1µF, X7R, capacitor

between this pin and BGND.

See pin 67 description.

Digital Input. This pin accepts either an input clock to phase lock the internal switching

frequency or a S_OUT signal from another EN23F0QI. Leave this pin floating if not used.

Digital Output. PWM signal is output on this pin. Leave this pin floating if not used.

Power OK is an open drain transistor (pulled up to AVIN or similar voltage) used for power

system state indication. POK is logic high when VOUT is -10% of VOUT nominal. Leave

this pin floating if not used.

67

68

69

70

VDDB

BGND

S_IN

O

G

I

S_OUT

O

71

POK

O

Input Enable. Applying a logic high to this pin enables the output and initiates a soft-start.

Applying a logic Low disables the output. Do not leave this pin floating.

3.3V Input power supply for the controller. Place a 0.1µF, X7R, capacitor between AVIN

and AGND.

Analog Ground. This is the ground return for the controller. Needs to be connected to a

quiet ground.

72

73

74

75

ENABLE

AVIN

I

P

G

I

AGND

M/S

A logic level low configures the device as Master and a logic level high configures the

device as a Slave. Connect to ground in standalone mode.

External Feedback Input. The feedback loop is closed through this pin. A voltage divider at

76

77

78

VFB

EAIN

SS

I/O VOUT is used to set the output voltage. The mid-point of the divider is connected to VFB. A

phase lead capacitor from this pin to VOUT is also required to stabilize the loop.

Optional Error Amplifier Input. Allows for customization of the control loop for performance

optimization. Leave this pin floating if unused.

O

Soft-Start node. The soft-start capacitor is connected between this pin and AGND. The

I/O value of this capacitor determines the startup time. See Soft-Start Operation in the

Functional Description section for details.

Programmable over-current protection. Placement of a resistor on this pin will adjust the

over-current protection threshold. See Table 2 for the recommended RCLX Value to set

OCP at the nominal value specified in the Electrical Characteristics table. No current limit

79

RCLX

I/O

protection when this pin is left floating.

Adding a resistor (R_FS) to this pin will adjust the switching frequency of the EN23F0QI. See

I/O Table 1 for suggested resistor values on R_FSfor various PVIN/VOUT combinations to

maximize efficiency. Do not leave this pin floating.

80

FADJ

82

93

CGND

PGND

G

Connect to GND plane at all times.

Not a perimeter pin. Device thermal pad to be connected to the system GND plane for heat-

sinking purposes.

G

Enpirion Confidential

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EN23F0QI

Absolute Maximum Ratings

CAUTION: Absolute Maximum ratings are stress ratings only. Functional operation beyond the recommended operating

conditions is not implied. Stress beyond the absolute maximum ratings may impair device life. Exposure to absolute

maximum rated conditions for extended periods may affect device reliability.

PARAMETER

Voltages on : PVIN, VOUT

SYMBOL

MIN

-0.5

MAX

15

UNITS

V

Pin Voltages – AVINO, AVIN, ENABLE, POK, S_IN, S_OUT, M/S

Pin Voltages – VFB, SS, EAIN, RCLX, FADJ

PVIN Slew Rate

2.5

-0.5

0.3

6.0

2.75

3

V

V/ms

°C

V

Storage Temperature Range

T_STG

-65

150

260

2000

500

Maximum Operating Junction Temperature

Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020A

ESD Rating (based on Human Body Model)

ESD Rating (based on CDM)

T_{J-ABS Max}

V

Recommended Operating Conditions

PARAMETER

SYMBOL

MIN

MAX

UNITS

Input Voltage Range

PVIN

4.5

14.0

V

AVIN: Controller Supply Voltage

Output Voltage Range (Note 1)

Output Current

AVIN

V_OUT

I_OUT

T_A

2.5

5.5

3.3

V

0.75

15

A

Operating Ambient Temperature

Operating Junction Temperature

-40

+85

+125

°C

T_J

Thermal Characteristics

PARAMETER

SYMBOL

TYP

UNITS

Thermal Shutdown

T_SD

160

35

13

1

°C

Thermal Shutdown Hysteresis

T_SDH

θ_JA

°C

Thermal Resistance: Junction to Ambient (0 LFM) (Note 2)

Thermal Resistance: Junction to Case (0 LFM)

°C/W

θ_JC

Note 1: RCLX resistor value may need to be raised for V_OUT> V_IN– 2.5V to increase current limit threshold. Contact

techsupport@enpirion.com for details.

Note 2: Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for

high thermal conductivity boards.

Enpirion Confidential

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EN23F0QI

Electrical Characteristics

NOTE: V_IN=12V, Minimum and Maximum values are over operating ambient temperature range unless otherwise noted.

Typical values are at T_A= 25°C.

PARAMETER

Operating Input Voltage

SYMBOL

PVIN

TEST CONDITIONS

MIN TYP MAX UNITS

4.5

14.0

V

Controller Input Voltage

AVIN

2.5

5.5

V

PVIN Under Voltage

Lock-out

Voltage above which UVLO is not

asserted

UVLO_PVIN

AVIN_UVLOR

2

V

AVIN Under Voltage

Lock-out rising

Voltage above which UVLO is not

asserted

2.3

AVIN Under Voltage

Lock-out falling

Voltage below which UVLO is

asserted

AVIN_OVLOF

I_AVIN

2.1

14

V

mA

V

AVIN Pin Input Current

Internal Linear Regulator

Output Voltage

AVINO

3.3

IPVIN_S

IAVIN_S

PVIN=12V, AVIN=3.3, ENABLE=0V

300

50

μA

Shut-Down Supply

Current

Feedback Node Voltage at:

V^IN= 12V, ILOAD = 0, TA = 25°C

Feedback Pin Voltage

V_FB

0.594

0.588

0.60

0.606

0.612

V

Feedback Node Voltage at:

4.5V ≤ V^IN≤ 14V

V

0A ≤ I_LOAD≤ 15A, TA = -40 to 85°C

VFB pin input leakage current

(Note 3)

Feedback pin Input

Leakage Current

I_FB

t_RISE

-5

5

nA

C

_SS= 47nF

V_OUTRise Time

1.96

2.8

47

3.64

ms

nF

A

(Note 3, Note 4 and Note 5)

Soft Start Capacitor

Range

C_{SS_RANGE}

Continuous Output

Current

I_{OUT_CONT}

I_OCP

0

15

Over Current Trip Level

ENABLE Logic High

ENABLE Logic Low

ENABLE Lockout Time

Reference Table 3

22.5

A

V

V_{ENABLE_HIGH}4.5V ≤ V_IN≤ 14V;

V_{ENABLE_LOW}4.5V ≤ V_IN≤ 14V;

T_ENLOCKOUT

1.8

0

AV_IN

0.6

V

8

4

ms

ENABLE pin Input

Current

I_ENABLE

F_SW

180kΩ Pull Down (Note 3)

RFADJ =3kΩ

μA

Switching Frequency

1.0

MHz

External SYNC Clock

Frequency Lock Range

F_{PLL_LOCK}

Range of SYNC clock frequency

0.8

1.8

1.6

S_IN Threshold – Low

S_IN Threshold – High

S_OUT Threshold – Low

V_{S_IN_LO}

V_{S_IN_HI}

S_IN Clock Logic Low Level

S_IN Clock Logic High Level

S_OUT Clock Logic Low Level

0.8

2.5

0.8

V

V_{S_OUT_LO}

S_OUT Threshold –

High

V_{S_OUT_HI}

POK_LT

S_OUT Clock Logic High Level

2.5

V

Percentage of Nominal Output

Voltage for POK to be Low

POK Lower Threshold

90

%

Enpirion Confidential

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EN23F0QI

PARAMETER

POK Output low Voltage

SYMBOL

V_POKL

TEST CONDITIONS

With 4mA Current Sink into POK

PVIN range: 4.5V ≤ V_IN≤ 15V

MIN TYP MAX UNITS

0.4

V

POK Output Hi Voltage

V_POKH

AVIN

V

POK pin V_OHleakage

current

I_POKL

V_T-LOW

V_T-HIGH

I_M/S

POK High (Note 3)

1

µA

V

M/S Pin Logic Low

M/S Pin Logic High

M/S Pin Input Current

Tie Pin to GND

0.8V

Pull up to AVIN Through an External

Resistor REXT

1.8V

V

100

VIN = 5.0V, REXT = 24.9kΩ

μA

Note 3: Parameter not production tested but is guaranteed by design.

Note 4: Rise time calculation begins when AVIN > V_UVLOand ENABLE = HIGH.

Note 5: V_OUTRise Time Accuracy does not include soft-start capacitor tolerance.

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EN23F0QI

Typical Performance Curves

Efficiency vs. Output Current

100

90

80

70

60

50

40

30

20

10

0

90

80

70

60

50

40

CONDITIONS

V_IN= 12.0V

AVIN = 3.3V

Dual Supply

VOUT = 3.3V

VOUT = 1.8V

VOUT = 1.2V

VOUT = 3.3V

VOUT = 1.8V

VOUT = 1.2V

CONDITIONS

V_IN= 10.0V

AVIN = 3.3V

Dual Supply

30

20

10

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

OUTPUT CURRENT(A)

OUTPUT CURRENT (A)

Output Current De-rating

15.0

14.0

13.0

12.0

11.0

10.0

9.0

15.0

14.0

13.0

12.0

11.0

10.0

9.0

CONDITIONS

V_IN= 10V

CONDITIONS

V_IN= 12V

T_JMAX= 125 C

8.0

T_JMAX= 125 C

8.0

VOUT = 1.2V

VOUT = 1.8V

Series1

θ

_JA= 13 C/W

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

θ

_JA= 13 C/W

7.0

13x12x3mm QFN

No Air Flow

13x12x3mm QFN

No Air Flow

6.0

5.0

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

Output Current De-rating

with Air Flow (200fpm)

Output Current De-rating

with Air Flow (400fpm)

15.0

14.0

13.0

12.0

11.0

10.0

9.0

15.0

14.0

13.0

12.0

11.0

10.0

9.0

CONDITIONS

V_IN= 12V

CONDITIONS

V_IN= 12V

T

_JMAX= 125 C

T_JMAX= 125 C

θ_JA= 9 C/W

13x12x3mm QFN

Air Flow (400fpm)

8.0

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

θ_JA= 10.5 C/W

13x12x3mm QFN

Air Flow (200fpm)

7.0

6.0

5.0

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

Enpirion Confidential

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EN23F0QI

Typical Performance Curves

Output Current De-rating

with Heat Sink

with Heat Sink and Air Flow (200fpm)

15.0

14.0

13.0

15.0

14.0

13.0

12.0

11.0

10.0

9.0

12.0

CONDITIONS

V_IN= 12V

T_JMAX= 125 C

CONDITIONS

11.0

10.0

9.0

V_IN= 12V

_JMAX= 125 C

_JA= 12 C/W

T

θ

_JA= 9.5 C/W

13x12x3mm QFN

No Air Flow

Heat Sink‐ Wakefield

ThermalSolutions

P/N 651‐B

8.0

AirFlow (200fpm)

Heat Sink - Wakefield

Thermal Solutions

P/N 651-B

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

7.0

6.0

5.0

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

Output Voltage vs. Output Current

Output Current De-rating

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

with Heat Sink and Air Flow (400fpm)

VIN = 8V

VIN = 10V

VIN = 12V

15.0

14.0

13.0

12.0

11.0

10.0

9.0

CONDITIONS

V_IN= 12V

T_JMAX= 125 C

θ

_JA= 8 C/W

13x12x3mm QFN

8.0

Air Flow (400fpm)

Heat Sink - Wakefield

Thermal Solutions

P/N 651-B

VOUT = 1.2V

VOUT = 1.8V

VOUT = 3.3V

7.0

CONDCIOTINODNISTIONS

V_{OUT_NIONM}==51.0.0VV

V

6.0

5.0

25 30 35 40 45 50 55 60 65 70 75 80 85

AMBIENT TEMPERATURE ( C)

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

OUTPUT CURRENT(A)

Output Voltage vs. Output Current

1.205

1.204

1.203

1.202

1.201

1.200

1.199

1.198

1.197

1.196

1.195

1.805

1.804

1.803

1.802

1.801

1.800

1.799

1.798

1.797

1.796

1.795

VIN = 8V

VIN = 10V

VIN = 12V

VIN = 8V

VIN = 10V

VIN = 12V

CONDITIONS

V_{OUT_NOM}= 1.8V

Note: Air flow or heat sink may be required for

highercurrents. See derating curves.

CONDCIOTINODNISTIONS

V_{OUT_NIONM}==51.0.2VV

V

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

OUTPUT CURRENT(A)

Enpirion Confidential

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EN23F0QI

Typical Performance Curves

Output Voltage vs. Output Current

Output Voltage vs. Temperature

2.505

1.204

1.203

1.202

1.201

1.200

1.199

1.198

1.197

1.196

VIN = 8V

VIN = 10V

VIN = 12V

2.504

2.503

2.502

2.501

2.500

2.499

2.498

2.497

2.496

2.495

CONDITIONS

V_IN= 8V

V

_{OUT_NOM}=1.2V

LOAD = 0A

LOAD = 4A

LOAD = 8A

LOAD = 12A

CONDITIONS

V_{OUT_NOM}= 2.5V

Note: Air flow or heat sink may be required for

higher currents. See derating curves.

-40

-15

10

35

60

85

30

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

AMBIENT TEMPERATURE ( C)

OUTPUT CURRENT(A)

Output Voltage vs. Temperature

1.204

1.203

1.202

1.201

1.200

1.199

1.198

1.197

1.196

1.204

1.203

1.202

1.201

1.200

1.199

1.198

1.197

1.196

CONDITIONS

V_IN= 10V

V

CONDITIONS

V_IN= 12V

V_{OUT_NOM}=1.2V

_{OUT_NOM}=1.2V

LOAD = 0A

LOAD = 4A

LOAD = 8A

LOAD = 12A

LOAD = 0A

LOAD = 4A

LOAD = 8A

LOAD = 12A

-40

-15

10

35

60

85

-40

-15

10

35

60

AMBIENT TEMPERATURE ( C)

Output Voltage vs. Temperature

Parallel Current Share Breakdown

1.204

1.203

1.202

1.201

1.200

1.199

1.198

1.197

1.196

20

17.5

15

CONDITIONS

V_IN= 14V

V

MASTER

SLAVE

IDEAL

_{OUT_NOM}=1.2V

12.5

10

LOAD = 0A

LOAD = 4A

LOAD = 8A

LOAD = 12A

7.5

5

CONDITIONS

EN23F0QI

_IN= 12V

V

2.5

0

V_OUT= 1.2V

-40

-15

10

35

60

85

0

5

10

15

20

25

AMBIENT TEMPERATURE ( C)

TOTAL OUTPUT CURRENT (A)

Enpirion Confidential

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EN23F0QI

Typical Performance Characteristics

Enable Startup/Shutdown Waveform (0A)

Enable Startup/Shutdown Waveform (5A)

ENABLE

VOUT

POK

VOUT

POK

CONDITIONS

VIN = 12V, VOUT = 3.3V, Load = 0A, Css = 47nF

CIN = 3x22µF(1206), COUT = 3x47µF(0805)+3x22µF(0805)

LOAD

CONDITIONS

VIN = 12V, VOUT = 3.3V, Load = 5A, Css = 47nF

CIN = 3x22µF(1206), COUT = 3x47µF(0805)+3x22µF(0805)

Enable Startup/Shutdown Waveform (10A)

Enable Startup/Shutdown Waveform (15A)

ENABLE

VOUT

POK

VOUT

POK

LOAD

CONDITIONS

VIN = 12V, VOUT = 3.3V, Load = 10A, Css = 47nF

VIN = 12V, VOUT = 3.3V, Load = 15A, Css = 47nF

CIN = 3x22µF(1206), COUT = 3x47µF(0805)+3x22µF(0805)

Power Up Waveform (0A)

Power Up Waveform (5A)

PVIN

VOUT

POK

VOUT

POK

LOAD

CONDITIONS

VIN = 12V, VOUT = 3.3V, Load = 5A, Css = 47nF,

CIN = 3x22µF(1206), COUT = 3x47µF(0805) + 3x22µF(0805)

VIN = 12V, VOUT = 3.3V, Load = 0A, Css = 47nF,

CIN = 3x22µF(1206), COUT = 3x47µF(0805) + 3x22µF(0805)

Enpirion Confidential

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EN23F0QI

Typical Performance Characteristics

Output Ripple at 20MHz Bandwidth

Power Up Waveform (15A)

VOUT = 1V

LOAD = 0A

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

PVIN

VOUT

POK

VOUT = 3.3V

(AC Coupled)

20mV / DIV

LOAD

CONDITIONS

VIN = 12V, VOUT = 3.3V, Load = 15A, Css = 47nF,

VIN = 12V, CIN = 3x22µF (1206), COUT = 3x47µF + 100µF (1206)

CIN = 3x22µF(1206), COUT = 3x47µF(0805) + 3x22µF(0805)

Output Ripple at 20MHz Bandwidth

Output Ripple at 500MHz Bandwidth

VOUT = 1V

LOAD = 0A

(AC Coupled)

VOUT = 1V

LOAD = 10A

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

VOUT = 3.3V

(AC Coupled)

VOUT = 3.3V

(AC Coupled)

20mV / DIV

CONDITIONS

VIN = 12V, CIN = 3x22µF (1206), COUT = 3x47µF + 100µF (1206)

Output Ripple at 500MHz Bandwidth

VOUT = 1V

LOAD = 2A

(AC Coupled)

Output Ripple at 500MHz Bandwidth

VOUT = 1V

LOAD = 6A

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

VOUT = 3.3V

(AC Coupled)

VOUT = 3.3V

(AC Coupled)

20mV / DIV

CONDITIONS

VIN = 12V, CIN = 3x22µF (1206), COUT = 3x47µF + 100µF (1206)

Enpirion Confidential

www.enpirion.com, Page 11

EN23F0QI

Typical Performance Characteristics

Output Ripple at 500MHz Bandwidth

Load Transient from 0 to 5A (V_OUT=1V)

VOUT = 1V

LOAD = 10A

(AC Coupled)

VOUT

(AC Coupled)

VOUT = 1.8V

(AC Coupled)

VOUT = 3.3V

(AC Coupled)

20mV / DIV

CONDITIONS

VIN = 12V, VOUT = 1.0V

CIN = 3 x 22µF (1206)

LOAD

CONDITIONS

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

VIN = 12V, CIN = 3x22µF (1206), COUT = 3x47µF + 100µF (1206)

Load Transient from 0 to 10A (V_OUT=1V)

Load Transient from 0 to 15A (V_OUT=1V)

VOUT

(AC Coupled)

CONDITIONS

VIN = 12V, VOUT = 1.0V

CIN = 3 x 22µF (1206)

CONDITIONS

VIN = 12V, VOUT = 1.0V

CIN = 3 x 22µF (1206)

LOAD

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

Load Transient from 0 to 5A (V_OUT=3.3V)

Load Transient from 0 to 10A (V_OUT=3.3V)

VOUT

(AC Coupled)

CONDITIONS

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

CONDITIONS

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

LOAD

Enpirion Confidential

www.enpirion.com, Page 12

EN23F0QI

Typical Performance Characteristics

Load Transient from 0 to 5A (V_OUT=3.3V)

Load Transient from 0 to 15A (V_OUT=3.3V)

VOUT

(AC Coupled)

CONDITIONS

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

LOAD

COUT = 3 x 47µF (0805) + 3 x 22µF (0805)

Using Best Performance Configuration

COUT = 3 x 47µF (1206) + 100µF (1206)

Using Best Performance Configuration

Load Transient from 0 to 10A (V_OUT=3.3V)

Load Transient from 0 to 15A (V_OUT=3.3V)

VOUT

(AC Coupled)

CONDITIONS

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

VIN = 12V, VOUT = 3.3V

CIN = 3 x 22µF (1206)

LOAD

COUT = 3 x 47µF (1206) + 100µF (1206)

Using Best Performance Configuration

COUT = 3 x 47µF (1206) + 100µF (1206)

Using Best Performance Configuration

Enpirion Confidential

www.enpirion.com, Page 13

EN23F0QI

Functional Block Diagram

S_OUT S_IN

Digital I/O

M/S

BTMP

PG

PVIN

Linear

Regulator

UVLO

To PLL

AVINO

Thermal Limit

Current Limit

Gate Drive

NC(SW)

VOUT

BGND

(-)

PWM

Comp

PGND

VDDB

(+)

Compensation

Network

PLL/Sawtooth

FADJ

EAIN

VFB

Generator

Compensation

Network

(-)

Error

Amp

(+)

Power

Good

Logic

POK

ENABLE

300k

180k

Soft Start

SS

Voltage Reference Generator

Band Gap

Reference

AVIN

AGND

Figure 4: Functional Block Diagram

Functional Description

wide loop bandwidth within a small foot print.

Synchronous Buck Converter

Protection Features:

The EN23F0QI is a highly integrated synchronous,

buck converter with integrated controller, power

MOSFET switches and integrated inductor. The

nominal input voltage (PVIN) range is 4.5V to 14V

and can support up to 15A of continuous output

current. The output voltage is programmed using

an external resistor divider network. The control

loop utilizes a Type IV Voltage-Mode compensation

network and maximizes on a low-noise PWM

topology. Much of the compensation circuitry is

internal to the device. However, a phase lead

capacitor is required along with the output voltage

feedback resistor divider to complete the Type IV

compensation network.. The high switching

frequency of the EN23F0QI enables the use of

small size input and output capacitors, as well as a

The power supply has the following protection

features:

•

Programmable Over-Current Protection

Thermal Shutdown with Hysteresis

Under-Voltage Lockout Protection

Additional Features:

•

Switching Frequency Synchronization

Programmable Soft-Start

Power OK Output Monitoring

Power Up Sequence

The EN23F0QI is designed to be powered by either

a single input supply (PVIN) or two separate

Enpirion Confidential

www.enpirion.com, Page 14

EN23F0QI

supplies: one for PVIN and the other for AVIN.

Single Input Supply Application (PVIN):

schematic for a dual input supply application.

For dual input supply applications, the sequencing

of the two input supplies, PVIN and AVIN, is very

important. During power up, neither ENABLE nor

PVIN should be asserted before AVIN. There are

two common acceptable turn-on/off sequences for

the device. ENABLE can be tied to AVIN and come

up with it, and PVIN can be ramped up and down

as needed. Alternatively, PVIN can be brought high

after AVIN is asserted, and the device can be

turned on and off by toggling the ENABLE pin.

PVIN may be applied before AVIN if ENABLE is

toggled after both PVIN and AVIN is applied.

Enable Operation

The ENABLE pin provides a means to enable

normal operation or to shut down the device. A

logic high will enable the converter into normal

operation. When the ENABLE pin is asserted (high)

the device will undergo a normal soft-start, allowing

the output voltage to rise monotonically into

regulation. A logic low will disable the converter and

the device will power down in a controlled manner.

The ENABLE signal has to be low for at least the

ENABLE Lockout Time (8ms) in order for the

device to be re-enabled.

Figure 5. Single Supply Applications Circuit

The EN23F0QI has an internal linear regulator that

converts PVIN to 3.3V. The output of the linear

regulator is provided on the AVINO pin once the

device is enabled. AVINO should be connected to

AVIN on the EN23F0QI. In this application, the

following external components are required: Place

a 1µF, X5R/X7R, capacitor between AVINO and

AGND as close as possible to AVINO. Place a

0.1µF, X5R/X7R, capacitor between AVIN and

AGND as close as possible to AVIN. In addition,

place a resistor (R_VB) between VDDB and AVIN, as

shown in Figure 5. Enpirion recommends

R_VB=4.75kΩ. In this application, ENABLE cannot be

asserted before PVIN. If no external enable signal

is used, tying ENABLE to AVIN meets this

requirement.

Pre-Bias Precaution

The EN23F0QI is not designed to be turned on into

a pre-biased output voltage. Be sure the output

capacitors are not charged or the output of the

EN23F0QI is not pre-biased when the EN23F0QI

is first enabled.

Frequency Synchronization

Dual Input Supply Application (PVIN and AVIN):

The switching frequency of the EN23F0QI can be

phase-locked to an external clock source to move

unwanted beat frequencies out of band. The

internal switching clock of the EN23F0QI can be

phase locked to a clock signal applied to the S_IN

pin. An activity detector recognizes the presence of

an external clock signal and automatically phase-

locks the internal oscillator to this external clock.

Phase-lock will occur as long as the input clock

frequency is in the range of 0.8MHz to 1.6MHz.

When no clock is present, the device reverts to the

free running frequency of the internal oscillator.

Adding a resistor (R_FS) to the FADJ pin will adjust

the switching frequency. If a 3KΩ resistor is placed

on FADJ the nominal switching frequency of the

EN23F0QI is 1MHz. Figure 7 shows the typical R_FS

resistor value versus switching frequency.

Figure 6: Dual Input Supply Application Circuit

In this application, place a 0.1µF, X7R, capacitor

between AVIN and AGND as close as possible to

AVIN. Refer to Figure 6 for a recommended

Enpirion Confidential

www.enpirion.com, Page 15

EN23F0QI

value.

Rfs vs. SW Frequency

1.800

1.600

1.400

1.200

1.000

0.800

0.600

POK Operation

The POK signal is an open drain signal (requires a

pull up resistor to AVIN or similar voltage) from the

converter indicating the output voltage is within the

specified range. Typically, a 100kꢀ or lower

resistance is used as the pull-up resistor. The POK

signal will be logic high (AVIN) when the output

voltage is above 90% of the programmed voltage

level. If the output voltage is below this point, the

POK signal will be a logic low. The POK signal can

be used to sequence down-stream converters by

tying to their enable pins.

CONDITIONS

V_IN= 6V to 12V

V_OUT=0.8V to 3.3V

0

2

4

6

8

10 12 14 16 18 20 22

R_FSRESISTOR VALUE (kꢀ)

Over-Current Protection (OCP)

Figure 7. R_FSversus Switching Frequency

The current limit function is achieved by sensing

the current flowing through a sense PFET. When

the sensed current exceeds the current limit, both

power FETs are turned off for the rest of the

switching cycle. If the over-current condition is

removed, the over-current protection circuit will re-

enable PWM operation. If the over-current condition

persists, the circuit will continue to protect the load.

The OCP trip point is nominally set as specified in

the Electrical Characteristics table. In the event the

OCP circuit trips consistently in normal operation,

the device enters a hiccup mode. While in hiccup

mode, the device is disabled for a short while and

restarted with a normal soft-start. The hiccup time

is approximately 32ms. This cycle can continue

indefinitely as long as the over current condition

persists.

The efficiency performance of the EN23F0QI for

various VOUTs can be optimized by adjusting the

switching frequency. Table 1 shows recommended

R_FSvalues for various VOUTs in order to optimize

performance of the EN23F0QI.

PVIN

VOUT

1.0V

1.2V

1.8V

2.5V

3.3V

R_FS

3k

3.3k

4.87k

10k

15k

12V

Table 1: Recommended R_FSValues

Spread Spectrum Mode

The OCP trip point can be programmed to trip at a

lower level via the RCLX pin. The value of the

resistor connected between RCLX and ground will

determine the OCP trip point. Generally, the higher

the RCLX value, the higher the current limit

threshold. Note that if RCLX pin is left open the

output current will be unlimited and the device will

not have current limit protection. Reference Table 2

for a list of recommended resistor values on RCLX

that will set the OCP trip point at the typical value of

The external clock frequency may be swept

between 0.8MHz and 1.6MHz at repetition

rates of up to 10 kHz in order to reduce EMI

frequency components.

Soft-Start Operation

Soft start is a means to ramp the output voltage

gradually upon start-up. The output voltage rise

time is controlled by the choice of soft-start

capacitor, which is placed between the SS pin (pin

78) and the AGND pin (pin 74).

22.5A,

also

specified

in

the

Electrical

Characteristics table.

Rise Time (ms): T_R≈ C_ss[nF] x 0.06

V_OUTRange

R_CLXValue

36.5k

0.6V < V_OUT≤ 0.9V

0.9V < V_OUT≤ 1.2V

1.2V < V_OUT≤ 2.0V

2.0V < V_OUT≤ 5.0V

During start-up of the converter, the reference

voltage to the error amplifier is linearly increased to

its final level by an internal current source of

approximately 10µA. Typical soft-start rise time is

~2.8ms with SS capacitor value of 47nF. The rise

time is measured from when V_IN> V_UVLORand

ENABLE pin voltage crosses its logic high

threshold to when V_OUTreaches its programmed

38.4k

40.2k

45.3k

Table 2: Recommended R_CLXValues vs. V_OUT

Enpirion Confidential

www.enpirion.com, Page 16

EN23F0QI

fed to the Slave device at its S_IN input. The Slave

device acts like an extension of the power FETs in

the Master. The inductor in the Slave prevents

crow-bar currents from Master to Slave due to

timing delays. Parallel operation in dual supply

mode is shown in Figure 9. Single supply mode

operation may also be implemented similarly. Note

that only critical components are shown. The red

text and red lines indicate the important parallel

operation connections and care should be taken in

layout to ensure low impedance between those

paths. The parallel current matching is illustrated in

Figure 8.

Thermal Overload Protection

Thermal shutdown circuit will disable device

operation when the junction temperature exceeds

approximately 150ºC. After a thermal shutdown

event, when the junction temperature drops by

approx 20ºC, the converter will re-start with a

normal soft-start.

Input Under-Voltage Lock-Out (UVLO)

Internal circuits ensure that the converter will not

start switching until the input voltage is above the

specified minimum voltage. Hysteresis, input de-

glitch and output leading edge blanking ensures

high noise immunity and prevents false UVLO

triggers.

Parallel Current Share Breakdown

20

Master / Slave (Parallel) Operation:

17.5

MASTER

Up to four EN23F0QI devices may be connected in

a Master/Slave configuration to handle larger load

currents. The maximum output current for each

parallel device will need to be de-rated by 20

percent so that no devices will over current due to

current mis-match. The Master device’s switching

clock may be phase-locked to an external clock

source via the S_IN pin or left open and use its

default switching frequency. The device is placed in

Master mode by pulling the M/S pin low or in Slave

mode by pulling M/S pin high. Note that the M/S pin

is also pulled low for standalone mode. In Master

mode, the internal PWM signal is output on the

S_OUT pin. This PWM signal from the Master is

15

SLAVE

IDEAL

12.5

10

7.5

5

CONDITIONS

EN23F0QI

V_IN= 12V

2.5

0

V

_OUT= 1.2V

0

5

10

15

20

25

30

TOTAL OUTPUT CURRENT(A)

Figure 8. Parallel Current Matching

Enpirion Confidential

www.enpirion.com, Page 17

EN23F0QI

Figure 9. Parallel Operation Illustration

Enpirion Confidential

www.enpirion.com, Page 18

EN23F0QI

Application Information

Output Voltage Programming and Loop

Compensation

Recommended Input Capacitors

Description

MFG

P/N

22µF, 16V, X5R,

10%, 1206

The EN23F0QI uses a Type IV Voltage Mode

compensation network. Type IV Voltage Mode

control is a proprietary Enpirion control scheme that

maximizes control loop bandwidth to deliver

excellent load transient responses and maintain

output regulation with pin point accuracy. For ease

of use, most of this network has been customized

and is integrated within the device package. The

EN23F0QI output voltage is programmed using a

simple resistor divider network (R_Aand R_B). The

feedback voltage at VFB is nominally 0.6V. R_Ais

predetermined based on Table 5 and R_Bcan be

calculated based on Figure 10. The values

recommended for C_OUT, C_A, R_CAand R_EAmake up

the external compensation of the EN23F0QI. It will

vary with each PVIN and VOUT combination to

optimize on performance. The EN23F0QI solution

can be optimized for either smallest size or highest

performance. Please see Table 5 for a list of

recommended R_A, C_A, R_CA, R_EAand C_OUTvalues for

each solution.

Murata

GRM31CR61C226ME15

22µF, 16V, X5R,

20%, 1206

Taiyo

Yuden

EMK316ABJ226ML-T

GRM32ER61E226KE15L

TMK325BJ226MM-T

22µF, 25V, X5R,

10%, 1210

Murata

22µF, 25V, X5R,

20%, 1210

Taiyo

Yuden

Table 3: Recommended Input Capacitors

Output Capacitor Selection

As seen from Table 5, the EN23F0QI has been

optimized for use with three 47µF/1206 plus one

100µF/1206 for best performance. For smallest

solution size, various combinations of output

capacitance may be used. See Table 5 for details.

Low ESR ceramic capacitors are required with X5R

or X7R rated dielectric formulation. Y5V or

equivalent dielectric formulations must not be

used as these lose too much capacitance with

frequency, temperature and bias voltage. Table

4 contains a list of recommended output capacitors.

Output ripple voltage is determined by the

aggregate output capacitor impedance. Capacitor

impedance, denoted as Z, is comprised of

capacitive reactance, effective series resistance,

ESR, and effective series inductance, ESL

reactance.

Placing output capacitors in parallel reduces the

impedance and will hence result in lower ripple

voltage.

1

=

+

+ ... +

Figure 10: V_OUTResistor Divider & Compensation

Z_Total

Z₁Z₂

Z_n

Components. See Table 5 for details.

Recommended Output Capacitors

Input Capacitor Selection

Description

47µF, 6.3V, X5R,

20%, 1206

47µF, 10V, X5R,

20%, 1206

22µF, 10V, X5R,

20%, 0805

22µF, 10V, X5R,

20%, 0805

MFG

P/N

The EN23F0QI requires three 22µF/1206 input

capacitor. Low-cost, low-ESR ceramic capacitors

should be used as input capacitors for this

converter. The dielectric must be X5R or X7R

rated. Y5V or equivalent dielectric formulations

must not be used as these lose too much

capacitance with frequency, temperature and

bias voltage. In some applications, lower value

capacitors are needed in parallel with the larger,

capacitors in order to provide high frequency

decoupling. Table 3 contains a list of recommended

input capacitors.

Murata

GRM31CR60J476ME19L

Taiyo

Yuden

LMK316BJ476ML-T

ECJ-2FB1A226M

Panasonic

Taiyo

Yuden

LMK212BJ226MG-T

GRM31CR60J107ME39L

JMK316BJ107ML-T

Murata

100µF, 6.3V, X5R,

20%, 1206

Taiyo

Yuden

Table 4: Recommended Output Capacitors

Enpirion Confidential

www.enpirion.com, Page 19

EN23F0QI

Best Performance

Smallest Solution Size

C_IN= 3 x 22µF/1206

V_OUT≤ 1.8V, C_OUT= 22µF/0805 + 2x47µF/0805

C_OUT= 3x47µF (1206) + 100µF(1206)

3.3V > V_OUT> 1.8V, C_OUT= 3x47µF/1206

R_A= 200 kΩ

R_A= 100 kΩ

PVIN VOUT C_A

R_CAR_EARipple Deviation

PVIN VOUT C_A

R_CA

R_EA

Ripple Deviation

(V)

(pF) (kΩ) (kΩ)

(mV)

25.6

24

(mV)

(V)

(pF) (kΩ) (kΩ)

(mV)

15

18

22

25

32

46

15

18

21

24

30

43

15

17

20

22

29

41

14

16

19

20

27

36

13

15

17

19

24

32

12

13

16

17

20

21

(mV)

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

15

12

10

18

12

18

15

12

22

15

18

15

27

22

18

39

27

22

47

39

33

27

68

47

19

22

24

14

16

19

22

12

14

16

19

10

13

15

6

0

23

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

1.0V

1.2V

1.5V

1.8V

2.5V

3.3V

12

36

27

20

10

Open

78

35

93

0

26.4

28.4

31.6

37.3

21.6

22.7

25.2

25.8

30

42

12

104

130

162

200

84

14V

0

45

12

56

0

78

15

114

31

10

22

0

38

22

97

0

39

18

118

130

172

213

85

12V

10V

8V

12V

10V

8V

0

41

18

56

0

84

22

30.8

18.8

20.4

22

116

37

15

56

0

41

47

100

120

140

177

230

83

0

42

39

0

23.6

26.5

28.9

17.2

18.7

20.1

20.9

23.6

22.8

13.8

15.2

16.4

19.6

20.4

21.1

12.4

13.4

14.3

15.4

15.5

12.9

46

33

56

0

90

33

122

17.2

18.7

20.1

20.9

23.6

22.8

13.8

15.2

16.4

19.6

20.4

21.1

12.4

13.4

14.3

15.4

15.5

12.9

22

200

150

82

0

90

0

107

138

178

239

99

0

56

0

68

6

39

10

13

4

200

150

100

56

0

105

118

138

183

250

123

132

145

156

216

253

0

6.6V

5V

6.6V

5V

0

56

0

4

10

13

1

200

100

0

56

1

Table 5: R_A, C_A, R_CAand R_EAValues for Various PVIN/VOUT Combinations: Best Performance vs. Smallest Solution

Size. Use the equations in Figure 10 to calculate R_B.

Note 6: Output ripple is measured at no load and nominal deviation is for a 15A load transient step.

Note 7: For compensation values of output voltage in between the specified output voltages, choose compensation values

of the lower output voltage setting.

Enpirion Confidential

www.enpirion.com, Page 20

EN23F0QI

Thermal Considerations

Thermal considerations are important power supply

design facts that cannot be avoided in the real

world. Whenever there are power losses in a

system, the heat that is generated by the power

dissipation needs to be accounted for. The Enpirion

PowerSoC helps alleviate some of those concerns.

For V_IN= 12V, V_OUT= 1.2V at 15A, η ≈ 80%

η = P_OUT/ P_IN= 80% = 0.8

P_IN= P_OUT/ η

P_IN≈ 18W / 0.8 ≈ 22.5W

The power dissipation (P_D) is the power loss in the

system and can be calculated by subtracting the

output power from the input power.

The Enpirion EN23F0QI DC-DC converter is

packaged in an 8x11x3mm 68-pin QFN package.

The QFN package is constructed with copper lead

frames that have exposed thermal pads. The

exposed thermal pad on the package should be

soldered directly on to a copper ground pad on the

printed circuit board (PCB) to act as a heat sink.

The recommended maximum junction temperature

for continuous operation is 125°C. Continuous

operation above 125°C may reduce long-term

reliability. The device has a thermal overload

protection circuit designed to turn off the device at

an approximate junction temperature value of

150°C.

P_D= P_IN– P_OUT

≈ 22.5W – 18W ≈ 4.5W

With the power dissipation known, the temperature

rise in the device may be estimated based on the

theta JA value (θ_JA). The θ_JAparameter estimates

how much the temperature will rise in the device for

every watt of power dissipation. The EN23F0QI has

a θ_JAvalue of 13 ºC/W without airflow.

Determine the change in temperature (ΔT) based

on P_Dand θ_JA.

ΔT = P_Dx θ_JA

The EN23F0QI is guaranteed to support the full 4A

output current up to 85°C ambient temperature.

The following example and calculations illustrate

the thermal performance of the EN23F0QI.

ΔT ≈ 4.5W x 13°C/W = 58.5°C ≈ 59°C

The junction temperature (T_J) of the device is

approximately the ambient temperature (T_A) plus

the change in temperature. We assume the initial

ambient temperature to be 25°C.

Example:

V_IN= 12V

T_J= T_A+ ΔT

V_OUT= 1.2V

T_J≈ 25°C + 59°C ≈ 84°C

I_OUT= 15A

The maximum operating junction temperature

(T_JMAX) of the device is 125°C, so the device can

operate at a higher ambient temperature. The

maximum ambient temperature (T_AMAX) allowed can

be calculated.

First calculate the output power.

P_OUT= 1.2V x 15A = 18W

Next, determine the input power based on the

efficiency (η) shown in Figure 11.

T

_AMAX= T_JMAX– P_Dx θ_JA

≈ 125°C – 59°C ≈ 66°C

Efficiency vs. Output Current

100

90

The maximum ambient temperature the device can

reach is 66°C given the input and output conditions.

Note that the efficiency will be slightly lower at

higher temperatures and this calculation is an

estimate.

80

70

60

50

40

CONDITIONS

V_IN= 12.0V

AVIN = 3.3V

Dual Supply

VOUT = 3.3V

VOUT = 1.8V

VOUT = 1.2V

30

20

10

0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15

OUTPUT CURRENT(A)

Figure 11: Efficiency vs. Output Current

Enpirion Confidential

www.enpirion.com, Page 21

EN23F0QI

Engineering Schematic

Figure 12: Critical Components Engineering Schematic

Enpirion Confidential

www.enpirion.com, Page 22

EN23F0QI

Layout Recommendation

on the inside wall, making the finished hole size

around 0.20-0.26mm. Do not use thermal reliefs or

spokes to connect the vias to the ground plane.

This connection provides the path for heat

dissipation from the converter.

Recommendation 5: Multiple small vias (the same

size as the thermal vias discussed in

recommendation 4) should be used to connect

ground terminal of the input capacitor and output

capacitors to the system ground plane. It is

preferred to put these vias along the edge of the

GND copper closest to the +V copper. These vias

connect the input/output filter capacitors to the

GND plane, and help reduce parasitic inductances

in the input and output current loops. If vias cannot

be placed under the capacitors, then place them on

both sides of the slit in the top layer PGND copper.

Recommendation 6: AVIN is the power supply for

the small-signal control circuits. It should be

connected to the input voltage at a quiet point. In

Figure 13 this connection is made at the input

capacitor.

Recommendation 7: The layer 1 metal under the

device must not be more than shown in Figure 13.

Refer to the section regarding Exposed Metal on

Bottom of Package. As with any switch-mode

DC/DC converter, try not to run sensitive signal or

control lines underneath the converter package on

other layers.

Recommendation 8: The V_OUTsense point should

be just after the last output filter capacitor. Keep the

sense trace short in order to avoid noise coupling

into the node. Contact Enpirion Technical Support

for any remote sensing applications.

Recommendation 9: Keep R_A, C_A, R_B, and R_CA

close to the VFB pin (Refer to Figure 13). The VFB

pin is a high-impedance, sensitive node. Keep the

trace to this pin as short as possible. Whenever

possible, connect R_Bdirectly to the AGND pins 52

and 53 instead of going through the GND plane.

Figure 13: Top Layer of Engineering Board (Top View).

Recommendation 1: Input and output filter

capacitors should be placed on the same side of

the PCB, and as close to the EN23F0QI package

as possible. They should be connected to the

device with very short and wide traces. Do not use

thermal reliefs or spokes when connecting the

capacitor pads to the respective nodes. The +V and

GND traces between the capacitors and the

EN23F0QI should be as close to each other as

possible so that the gap between the two nodes is

minimized, even under the capacitors.

Recommendation 2: The PGND connections for

the input and output capacitors on layer 1 need to

have a slit between them in order to provide some

separation between input and output current loops.

Recommendation 3: The system ground plane

should be the first layer immediately below the

surface layer. This ground plane should be

continuous and un-interrupted below the converter

and the input/output capacitors.

Recommendation 10: Follow all the layout

recommendations as close as possible to optimize

performance. Enpirion provides schematic and

layout reviews for all customer designs. Contact

Enpirion Applications Engineering for detailed

support (techsupport@enpirion.com).

Recommendation 4: The thermal pad underneath

the component must be connected to the system

ground plane through as many vias as possible.

The drill diameter of the vias should be 0.33mm,

and the vias must have at least 1 oz. copper plating

Enpirion Confidential

www.enpirion.com, Page 23

EN23F0QI

Design Considerations for Lead-Frame Based Modules

Exposed Metal on Bottom of Package

Lead-frames offer many advantages in thermal performance, in reduced electrical lead resistance, and in

overall foot print. However, they do require some special considerations.

In the assembly process lead frame construction requires that, for mechanical support, some of the lead-frame

cantilevers be exposed at the point where wire-bond or internal passives are attached. This results in several

small pads being exposed on the bottom of the package, as shown in Figure 14.

Only the thermal pad and the perimeter pads are to be mechanically or electrically connected to the PC board.

The PCB top layer under the EN23F0QI should be clear of any metal (copper pours, traces, or vias) except for

the thermal pad. The “shaded-out” area in Figure 14 represents the area that should be clear of any metal on

the top layer of the PCB. Any layer 1 metal under the shaded-out area runs the risk of undesirable shorted

connections even if it is covered by soldermask.

The solder stencil aperture should be smaller than the PCB ground pad. This will prevent excess solder from

causing bridging between adjacent pins or other exposed metal under the package. Please consult the

Enpirion Manufacturing Application Note for more details and recommendations.

Figure 14: Lead-Frame exposed metal (Bottom View)

Shaded area highlights exposed metal that is not to be mechanically or electrically connected to the PCB.

Enpirion Confidential

www.enpirion.com, Page 24

EN23F0QI

Recommended PCB Footprint

Figure 15: EN23F0QI PCB Footprint (Top View)

Enpirion Confidential

www.enpirion.com, Page 25

EN23F0QI

Package and Mechanical

Figure 16: EN23F0QI Package Dimensions (Bottom View)

Packing and Marking Information: http://www.enpirion.com/resource-center-packing-and-marking-information.htm

Contact Information

Enpirion, Inc.

Perryville III Corporate Park

53 Frontage Road - Suite 210

Hampton, NJ 08827 USA

Phone: 1.908.894.6000

Fax: 1.908.894.6090

Enpirion reserves the right to make changes in circuit design and/or specifications at any time without notice. Information furnished by Enpirion is

believed to be accurate and reliable. Enpirion assumes no responsibility for its use or for infringement of patents or other third party rights, which may

result from its use. Enpirion products are not authorized for use in nuclear control systems, as critical components in life support systems or equipment

used in hazardous environment without the express written authority from Enpirion

Enpirion Confidential

www.enpirion.com, Page 26


型号：	EN23F0QI
厂家：	ENPIRION, INC.
描述：	15A Voltage Mode Synchronous Buck PWM 15A电压模式同步降压PWM
文件：	总26页 (文件大小：1852K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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