ML4902 Ver la hoja de datos (PDF) - Micro Linear Corporation

Número de pieza

componentes Descripción

Lista de partido

ML4902

High Current Synchronous Buck Controller

Micro Linear Corporation 

ML4902

FUNCTIONAL DESCRIPTION (Continued)

UNDERVOLTAGE LOCKOUT

The ML4902 has hysteretic undervoltage lockout

protection circuits for both the 12V (VDD) and 5V (VCC)

supplies. During an input undervoltage condition, the

internal reference and voltage monitor circuits remain in

operation, but N DRV H and N DRV L are disabled and

the PWR GOOD output will be false (low).

COMPENSATION

The COMP pin is connected to the output of the

transconductance amplifier which forms the gain block

for the proportional control loop of the ML4902. An RC

network from this pin to GND is used to compensate the

amplifier.

5VIN

12VIN

VID0

VID1

VID2

VID3

VID4

OUTEN

PWRGD

C22

1nF

C14

220nF

16V

C20

22µF

25V

C10

220nF

16V

C12

220nF

16V

R3

1MΩ

L1

1µH

1

D0

20

PROTECT

2

D1

3

D2

4

D3

19

VDD

18

VCC

17

N DRV H

5

RANGE

16

N DRV L

6 SHDN

15

PWR GND

7

NC

14

NC

8

PWR GOOD

13

COMP

9

VREF

10

GND

12

ISENSE

11

VFB

U1

ML4902

R2

1kΩ

C11

220nF

16V

C1 C2 C3

Q1, Q2

2X IRF7413

Q3, Q4

2X IRF7413

L2

1.4µH

R1

12Ω

C4-C9

R5

100Ω

C19

C15

VCCP

R4

VSS

470kΩ

C13

C1 - C9 - 1500µF, 6.3V, Sanyo 6MV1500GX

1nF

C15, C19 - 100nF ceramic

Figure 1. Typical VRM Circuit

6

Share Link: