IFX91041_技术文档

IFX91041

1.8A DC/DC Step-Down Voltage Regulator

5.0V, 3.3V or Adjustable Output Voltage

IFX91041EJV50

IFX91041EJV33

IFX91041EJV

Data Sheet

Rev. 1.02, 2010-02-23

Standard Power

1.8A DC/DC Step-Down Voltage Regulator

IFX91041

1

Overview

•

1.8A step down voltage regulator

Output voltage versions: 5.0 V, 3.3 V and adjustable

± 2% output voltage tolerance (+-4% for full load current range)

Integrated power transistor

PWM regulation with feedforward

Input voltage range from 4.75V to 45V

370 kHz switching frequency

Synchronization input

Very low shutdown current consumption (<2uA)

Soft-start function

Input undervoltage lockout

Suited for industrial applications: T_j= -40 °C to +125 °C

Green Product (RoHS compliant)

PG-DSO-8-27

For automotive and transportation applications, please refer to the Infineon TLE and TLF voltage regulator series.

Description

The IFX91041 series are monolithic integrated circuits that provide all active functions for a step-down (buck)

switching voltage regulator, capable of driving up to 1.8A load current with excellent line and load regulation.

These devices are suited for use in industrial applications featuring protection functions such as current limitation

and overtemperature shutdown. Versions with a fixed 5.0V and 3.3V (IFX91041EJV50, IFX91041EJV33) output

voltage as well as an adjustable device (IFX91041EJV) with 0.60V reference feedback voltage are available. The

switching frequency of 370kHz allows to use small and inexpensive passive components. The IFX91041 features

an enable function reducing the shut-down current consumption to <2uA. The voltage mode regulation scheme of

this device provides a stable regulation loop maintained by small external compensation components. Besides

the feedforward control path offers an excellent line transient rejection. The integrated soft-start feature limits the

current peak as well as voltage overshot at start-up.

Type

Package

Marking

I9104150

I9104133

I91041V

IFX91041EJV50

IFX91041EJV33

IFX91041EJV

PG-DSO-8-27

Data Sheet

2

Rev. 1.02, 2010-02-23

IFX91041

Block Diagram

2

Block Diagram

EN

VS

7

8

Enable

Charge Pump

Over

Temperature

Shutdown

BDS

BUO

FB

5

Feedforward

COMP

Buck

Converter

3

6

4

SYNC

Oscillator

1

Bandgap

Reference

Soft start ramp

generator

IFX91041

2

GND

Figure 1

Block Diagram

Data Sheet

3

Rev. 1.02, 2010-02-23

IFX91041

Pin Configuration

3

Pin Configuration

3.1

Pin Assignment

IFX91041

SYNC

GND

COMP

FB

1

8

7

6

5

VS

2

3

4

EN

BUO

BDS

S08_PIN.vsd

Figure 2

Pin Configuration

3.2

Pin Definitions and Functions

Pin Symbol Function

1

SYNC

Synchronization Input.

Connect to an external clock signal in order to synchronize/adjust the switching frequency.

If not used connect to GND.

2

3

GND

Ground.

Compensation Input.

COMP

Frequency compensation for regulation loop stability.

Connect to compensation RC-network.

4

FB

Feedback Input.

For the adjustable output voltage versions (IFX91041EJV) connect via voltage divider to output

capacitor.

For the fixed voltage version (IFX91041EJV50, IFX91041EJV33) connect this pin directly to the

output capacitor.

5

6

BDS

BUO

Buck Driver Supply Input.

Connect the bootstrap capacitor between this pin and pin BUO.

Buck Switch Output.

Source of the integrated power-DMOS transistor. Connect directly to the cathode of the catch

diode and the buck circuit inductance.

7

8

EN

VS

Enable Input.

Active-high enable input with integrated pull down resistor.

Supply Voltage Input.

Connect to supply voltage source.

Exposed Pad Connect to heatsink area and GND by low inductance wiring.

Data Sheet

4

Rev. 1.02, 2010-02-23

IFX91041

General Product Characteristics

4

General Product Characteristics

4.1

Absolute Maximum Ratings

Absolute Maximum Ratings¹⁾

T_j= -40 °C to +125 °C; all voltages with respect to ground (unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Max.

Unit Conditions

Min.

-0.3

Voltages

4.1.1

Synchronization Input

Compensation Input

Feedback Input

V_SYNC

V_COMP

V_FB

5.5

6.2

5.5

6.2

10

V

–

t < 10s²⁾

4.1.2

4.1.3

4.1.4

–

t < 10s¹⁾

-0.3

IFX91041EJV50;

IFX91041EJV33

4.1.5

4.1.6

5.5

V

IFX91041EJV

Buck Driver Supply Input

V_BDS

V_BUO

- 0.3

+ 5.5

4.1.7

4.1.8

4.1.9

Buck Switch Output

Enable Input

V_BUO

V_EN

-2.0

-40

V

_VS+ 0.3

V

45

Supply Voltage Input

V_VS

-0.3

Temperatures

4.1.10

4.1.11

Junction Temperature

Storage Temperature

T_j

-40

-55

150

°C

–

T_stg

ESD Susceptibility

4.1.12

ESD Resistivity

V_ESD

-2

2

kV

HBM ³⁾

1) Not subject to production test, specified by design.

2) Exposure to those absolute maximum ratings for extended periods of time (t > 10s) may affect device reliability

3) ESD susceptibility HBM according to EIA/JESD 22-A 114B (1.5kΩ,100pF).

Note:Stresses above the ones listed here may cause permanent damage to the device. Exposure to absolute

maximum rating conditions for extended periods may affect device reliability.

Note:Integrated protection functions are designed to prevent IC destruction under fault conditions described in the

data sheet. Fault conditions are considered as “outside” normal operating range. Protection functions are

not designed for continuous repetitive operation.

Data Sheet

5

Rev. 1.02, 2010-02-23

IFX91041

General Product Characteristics

4.2

Functional Range

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

4.75

0.60

18

Max.

45

4.2.1

4.2.2

4.2.3

4.2.4

4.2.5

4.2.6

Supply Voltage

V_S

V

–

Output Voltage adjust range

Buck inductor

V_CC

L_BU

16

V

IFX91041EJV

56

µH

µF

Ω

–

Buck capacitor

C_BU1

ESR_BU1

T_j

33

120

0.3

150

1)

Buck capacitor ESR

Junction Temperature

–

-40

°C

–

1) See section ““Application Information” on Page 12” for loop compensation requirements.

Note:Within the functional range the IC operates as described in the circuit description. The electrical

characteristics are specified within the conditions given in the related electrical characteristics table.

4.3

Thermal Resistance

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

Typ.

–

Max.

4.3.1

4.3.2

Junction to Case¹⁾

Junction to ambient¹⁾

R_thJC

R_thJA

–

12

–

K/W

–

2)

52

1) Not subject to production test, specified by design.

2) According to Jedec JESD52-1,-5,-7 at natural convection on 2s2p FR4 PCB for 1W power dissipation. PCB

76.2x114.3x1.5mm³with 2 inner copper layers of 70µm thickness. Thermal via array conected to the first inner copper layer

under the exposed pad.

Data Sheet

6

Rev. 1.02, 2010-02-23

IFX91041

Buck Regulator

5

Buck Regulator

5.1

Description

The gate of the power switch is driven by the external capacitor connected to pin BDS (Buck Driver Supply) using

the bootstrap principle. An integrated under voltage lockout function supervising the ’bootstrap’ capacitor voltage

ensures that the device is always driven with a sufficient bootstrap voltage in order to prevent from extensive heat

up of the power transistor. An integrated charge pump supports the gate drive in case of low input supply voltage,

small differential voltage between input supply and output voltage at low current and during startup. In order to

minimize emission, the charge pump is switched off if the input voltage is sufficient for supplying the bootstrap.

The soft start function generates a defined ramp of the output voltage during the first 0.5 ms (typ.) after device

initialization. The device initialization is triggered either by the EN voltage level crossing the turn-on threshold,

rising supply voltage (during EN=H), and also when the device restarts a after thermal shutdown. The ramp starts

after the BDS external capacitor is charged.

The regulation scheme uses a voltage controlled pulse width modulation with feed forward path (the feed forward

operates for supply voltages from 8.0V to 36V) which provides a fast line transient reaction.

In order to maintain the output voltage regulation even under low duty cycle conditions (light load conditions down

to ICC=0mA, high input voltage) a pulse skipping operation mode is implemented. Pulse skipping is also used for

operation with low supply voltages, related to high duty cycles >92%

In case of a lost connection to the pin FB , an internal pull-up current prevents from a uncontrolled rise of the output

voltage (version IFX91041EJV only).

OC

Comp.

V_S

COMP

L when Overcurrent

=

BDS

Error

Amp.

Charge

Pump

Gate Driver

Supply

PWM

Comp.

NOR1

FB

H when

Error-Signal <

Error-Ramp

Output Stage

OFF when H

_

>1

Error-Signal

Error-Ramp

INV

1

Soft start

H =

OFF

H =

ON

R

S

&

Q

Power

D-MOS

OFF

when H

L when

Gate

Driver

V_Ref

0.6 V

R

T_j> 175 °C

=

&

Q

BUO

Ramp

Generator

L when

Output

overvoltage

Q

Feedforward

ΔV=k V_S

PWM-FF

X

Oscillator

Schmitt-Trigger 1

V_high

NAND 2

&

S

Q

V_max

V_min

Ramp

Clock Error-FF

BDS

UV Comp.

SYNC

V_low

H when

UV at V_BDS

t_rt_ft_r

t

=

Figure 3

Block Diagram Buck Regulator

Data Sheet

7

Rev. 1.02, 2010-02-23

IFX91041

Buck Regulator

5.2

Electrical Characteristics

Electrical Characteristics: Buck Regulator

V_S= 6.0 V to 40 V, T_j= -40 °C to +125 °C, all voltages with respect to ground (unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Unit Conditions

Min. Typ. Max.

IFX91041EJV50;

_VEN= V_S

5.2.1

Output voltage

V_FB

4.90 5.00

5.10

V

0.1A < I_CC< 1.0A

5.2.2

5.2.3

V_FB

4.80 5.00

3.23 3.30

5.20

3.37

V

IFX91041EJV50;

V

_VEN= V_S;

1mA < I_CC< 1.8A

IFX91041EJV33;

Output voltage

V_FB

V

_VEN= V_S;

0.1A < I_CC< 1.0A

IFX91041EJV33;

5.2.4

5.2.5

V_FB

3.17 3.30

0.588 0.60

3.43

V

_VEN= V_S;

1mA < I_CC< 1.8A

IFX91041EJV;

0.612

V

_VEN= V_S;

FB connected to V_CC;

V_S= 12V

0.1A < I_CC< 1.0A

IFX91041EJV;

5.2.6

V_FB

0.576 0.60

0.624

V

_VEN= V_S;

FB connected to V_CC;

V_S= 12V

1mA < I_CC< 1.8A

5.2.7

5.2.8

5.2.9

Minimum output load requirement I_CC,MIN

0

–

mA IFX91041EJV50¹⁾

IFX91041EJV33¹⁾

1

mA

1.5

mA IFX91041EJV

V_CC> 3V¹⁾

5.2.10

5.2.11

5

mA IFX91041EJV

V_CC> 1.5V¹⁾

10

-1

–

mA IFX91041EJV

V_CC> =0.6V¹⁾

5.2.12 FB input current

5.2.13 FB input current

I_FB

-0.1

–

0

µA

IFX91041EJV

_FB= 0.6V

V

900

IFX91041EJV50,

IFX91041EJV33

5.2.14 Power stage on-resistance

5.2.15 Current transition rise/fall time

5.2.16 Buck peak over current limit

R_on

–

500

–

mΩ tested at 300 mA

t_r

–

50

–

ns

A

I_CC=1 A ²⁾

I_BUOC

V_BDS,off

2.2

3.6

–

5.2.17 Bootstrap under voltage lockout,

turn-off threshold

V_BUO

+3.3

–

V

Bootstrap voltage

decreasing

5.2.18 Charge pump current

I_CP

2

–

mA V_S= 12V;

_BUO= V_BDS= GND

V

Data Sheet

8

Rev. 1.02, 2010-02-23

IFX91041

Buck Regulator

Electrical Characteristics: Buck Regulator

V_S= 6.0 V to 40 V, T_j= -40 °C to +125 °C, all voltages with respect to ground (unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Unit Conditions

Min. Typ. Max.

5.2.19 Charge pump switch-off threshold V_BDS

-

–

5

V

(V_BDS- V_BUO) increasing

V_BUO

3)

5.2.20 Maximum duty cycle

5.2.21 Soft start ramp

D_max

t_start

–

100

750

%

350 500

µs

V

_FBrising from 5% to

95% of V_FB,nom

5.2.22 Input under voltage shutdown

threshold

V_S,off

3.75

–

V

V_Sdecreasing

5.2.23 Input voltage startup threshold

V_S,on

V_S,hyst

–

4.75

–

V

V_Sincreasing

5.2.24 Input under voltage shutdown

hysteresis

150

mV

–

1) Not subject to production test, application related parameter

2) Not subject to production test; specified by design.

3) Consider “Chapter 4.2, Functional Range”

Data Sheet

9

Rev. 1.02, 2010-02-23

IFX91041

Module Enable and Thermal Shutdown

6

Module Enable and Thermal Shutdown

6.1

Description

With the enable pin the device can be set in off-state reducing the current consumption to less than 2µA.

The enable function features an integrated pull down resistor which ensures that the IC is shut down and the power

switch is off in case the pin EN is left open.

The integrated thermal shutdown function turns the power switch off in case of overtemperature. The typ. junction

shutdown temperature is 175°C, with a min. of 160°C. After cooling down the IC will automatically restart

operation. The thermal shutdown is an integrated protection function designed to prevent IC destruction when

operating under fault conditions. It should not be used for normal operation.

6.2

Electrical Characteristics Module Enable, Bias and Thermal Shutdown

Electrical Characteristics: Enable, Bias and Thermal Shutdown

V_S= 6.0 V to 40 V, T_j= -40 °C to +125 °C, all voltages with respect to ground (unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

Typ.

Max.

6.2.1

6.2.2

Current Consumption,

shut down mode

I_q,OFF

I_q,ON

–

0.1

2

µA

V

_EN= 0.8V;

T_j< 105°C; V_S= 16V

V_EN= 5.0V; I_CC= 0mA;

Current Consumption,

active mode

–

7

mA

V_S= 16V

FB connected to V_OUT

6.2.3

Current Consumption,

active mode

I_q,ON

10

mA

V_EN= 5.0V; I_CC= 1.8A;

V_S= 16V

FB connected to V_OUT

1)

6.2.4

6.2.5

6.2.6

6.2.7

6.2.8

6.2.9

Enable high signal valid

Enable low signal valid

Enable hysteresis

V_EN,lo

V_EN,hi

V_EN,HY

I_EN,hi

3.0

–

V

–

0.8

400

30

1

V

–

1)

50

–

200

–

mV

µA

°C

K

Enable high input current

Enable low input current

V

_EN= 16V

I_EN,lo

–

0.1

175

15

V

1)

_EN= 0.5V

Over temperature shutdown T_j,sd

160

–

190

–

1)

6.2.10 Overtemperatureshutdown T_{j,sd_hyst}

hysteresis

1) Specified by design. Not subject to production test.

Data Sheet

10

Rev. 1.02, 2010-02-23

IFX91041

Module Oscillator

7

Module Oscillator

7.1

Description

The oscillator turns on the power switch with a constant frequency while the buck regulating circuit turns the power

transistor off in every cycle with an appropriate time gap depending on the output and input voltage.

The internal sawtooth signal used for the PWM generation has an amplitude proportional to the input supply

voltage (feedforward).

The turn-on frequency can optionally be set externally via the ’SYNC’ pin using a TTL compatible input signal. In

this case the synchronization of the PWM-on signal refers to the falling edge of the ’SYNC’-pin input signal. In case

the synchronization to an external clock signal is not needed the ’SYNC’ pin should be connected to GND.

Leaving pin SYNC open or short-circuiting it to GND leads to normal operation with the internal switching

frequency.

7.2

Electrical Characteristics Module Oscillator

Electrical Characteristics: Buck Regulator

V_S= 6.0 V to 40 V, T_j= -40 °C to +125 °C, all voltages with respect to ground (unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

330

200

Typ.

Max.

7.2.1

7.2.2

7.2.3

7.2.4

7.2.5

Oscillator frequency

f_osc

370

420

530

kHz

V

_SYNC= 0V

Synchronization capture range

SYNC signal high level valid

SYNC signal low level valid

SYNC input internal pull-down

f_sync

1)

V_SYNC,hi2.9

V_SYNC,lo

0.8

1.4

V

R_SYNC

0.60

1.0

MΩ

V

_SYNC= 5V

1) Synchronization of PWM-on signal to falling edge.

Data Sheet

11

Rev. 1.02, 2010-02-23

IFX91041

Application Information

8

Application Information

Note:The following information is given as a hint for the implementation of the device only and shall not be

regarded as a description or warranty of a certain functionality, condition or quality of the device.

8.1

Frequency Compensation

The stability of the output voltage can be achieved with a simple RC connected between pin COMP and GND. The

standard configuration using the swiching frequency of the internal oscillator is a ceramic capacitor C_COMP= 22nF

and R_COMP= 22kΩ. By slight modifications to the compensation network the stability can be optimized for different

application needs, such as varying switching frequency (using the sychronizing function), different types of buck

capacitor (ceramic or tantalum) etc.

The compensation network is essential for control loop stability. Leaving pin COMP open might lead to instable

operation.

8.2

Compensating a tantalum buck capacitor C_BU1

The TLE control loop is optimized for ceramic buck capacitors C_BU. In order to maintain stability also for tantalum

capacitors with ESR up to 300mΩ, an additional compensation capacitance C_COMP2at pin COMP to GND is

required. It’s value calculates:

C_COMP2= C_BU* ESR(C_BU) / R_COMP,

whereas C_COMP2needs to stay below 5nF.

Application_C-COMP2.vsd

COMP

3

IFX91041

C_COMP

C_COMP2

2

R_COMP

GND

Figure 4

High-ESR buck capacitor compensation

8.3

Catch Diode

In order to minimize losses and for fast recovery, a schottky catch diode is required. Disconnecting the catch diode

during operation might lead to destruction of the IC.

Data Sheet

12

Rev. 1.02, 2010-02-23

IFX91041

Application Information

8.4

IFX91041EJV50, IFX91041EJV33 with fixed Output Voltage

L_I

D₁

22…47µH

V_Batt

Ignition Key

Terminal 15

EN

VS

7

8

Enable

Charge Pump

Over

Temperature

Shutdown

BDS

BUO

5

Feedforward

C_BOT

220nF

L_BU

COMP

SYNC

Buck

Converter

3

6

4

V_OUT

47µH

D_BU

C_COMP

C_BU1

Oscillator

C_BU2

1

FB

100µF

220nF

R_COMP

Bandgap

Reference

Soft start ramp

generator

IFX91041EJV50

IFX91041EJV33

2

GND

Figure 5

Application Diagram IFX91041EJV50 or IFX91041EJV33

Note:This is a very simplified example of an application circuit. The function must be verified in the real application

Data Sheet

13

Rev. 1.02, 2010-02-23

IFX91041

Application Information

8.5

Adjustable Output Voltage Device

L_I

D₁

22…47µH

V_Batt

Ignition Key

Terminal 15

EN

VS

7

8

Biasing &

Enable

Charge Pump

Over

Temperature

Shutdown

BDS

5

Feedforward

C_BOT

220nF

L_BU

COMP

SYNC

Buck

Converter

3

BUO

D_BU

6

4

V_OUT

47µH

C_COMP

C_BU1

100µF

Oscillator

C_BU2

R₁

R₂

1

FB

220nF

R_COMP

Bandgap

Reference

Soft start ramp

generator

C_FB

IFX91041EJV

2

GND

Figure 6

Application Diagram IFX91041EJV

Note:This is a very simplified example of an application circuit. The function must be verified in the real application

The output voltage of the IFX91041EJV can be programmed by a voltage divider connected to the feedback pin

FB. The divider cross current should be 300 µA at minimum, therefore the maximum R₂calculates:

R₂≤ V_FB/ I_R2--> R₂≤ 0.6V / 300 µA = 2 kΩ

For the desired output voltage level V_CC, R₁calculates then (neglecting the small FB input current):

V

CC

⎛

⎞

R

= R ---------- – 1 .

1

2

⎝

⎠

V

FB

Add a 0.5 nF capacitor close to FB pin.

Data Sheet

14

Rev. 1.02, 2010-02-23

IFX91041

Package Outlines

9

Package Outlines

0.35 x 45˚

1)

0.1

3.ꢀ

0.1 C D 2x

8˚ MAX.

0˚...8˚

+0.06

0.1ꢀ

0.08

Seating Plane

C

0˚...8˚

1.27

0.64

0.25

2)

0.0ꢀ

0.2

0.41

6

M

0.2

D 8x

0.2

C A-B D 8x

D

Bottom View

0.1

3

A

1

4

8

5

1

4

8

5

B

0.1 C A-B 2x

1)

0.1

4.ꢀ

Index Marking

1) Does not include plastic or metal protrusion of 0.15 max. per side

2) Lead width can be 0.61 max. in dambar area

3) JEDEC reference MS-012 variation BA

GPS01206

Figure 7

Outline PG-DSO-8-27

Green Product (RoHS compliant)

To meet the world-wide customer requirements for environmentally friendly products and to be compliant with

government regulations the device is available as a green product. Green products are RoHS-Compliant (i.e

Pb-free finish on leads and suitable for Pb-free soldering according to IPC/JEDEC J-STD-020).

For further package information, please visit our website:

Dimensions in mm

http://www.infineon.com/packages.

Data Sheet

15

Rev. 1.02, 2010-02-23

IFX91041

Revision History

10

Revision History

Rev.1.02 2010-02-23 Editorial change

Rev.1.01 2009-10-19 Overview page: Inserted reference statement to TLE/TLF series.

Rev.1.0 2009-05-04 Final data sheet

Data Sheet

16

Rev. 1.02, 2010-02-23

Edition 2010-02-23

Published by

Infineon Technologies AG

81726 Munich, Germany

Legal Disclaimer

The information given in this document shall in no event be regarded as a guarantee of conditions or

characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any

information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties

and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights

of any third party.

Information

For further information on technology, delivery terms and conditions and prices, please contact the nearest

Infineon Technologies Office (www.infineon.com).

Warnings

Due to technical requirements, components may contain dangerous substances. For information on the types in

question, please contact the nearest Infineon Technologies Office.

Infineon Technologies components may be used in life-support devices or systems only with the express written

approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure

of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support

devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain

and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may

be endangered.


型号：	IFX91041
厂家：	Infineon
描述：	1.8A DC/DC Step-Down Voltage Regulator 5.0V, 3.3V or Adjustable Output Voltage 1.8A DC / DC降压型稳压器5.0V ， 3.3V或可调输出电压稳压器
文件：	总17页 (文件大小：1288K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

IFX91041 [INFINEON]

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