9

 2007 Semtech Corp.

www.semtech.com

SC4624

POWER MANAGEMENT

Pin Descriptions

Pin

SO-16

Pin

MLPQ-20 Pin Name

Pin Functions

6

1

PVIN1

Power supply voltage for high side MOSFETs.

8

2

ISET

Current limit setting pin. A resistor connected between ISET and AGND sets the over

current protection threshold. A ceramic decoupling between ISET pin to AGND have to

be reserved to prevent from noise influence.

9

3

SS

Soft start time setting pin. A cap connected from this pin to GND sets the soft start up

time.

10

4

FS

Oscillator frequency setting pin. An external resistor connected from this pin to GND

sets the oscillator frequency.

11,15

5,12

VCC

Power supply voltage for the analog section of the controller.

12

6

PGOOD Power good indicator. It is an open drain output. Low when the output is below the

power good threshold level.

7,8,9

NC

No connection.

13

10

COMP

This is the output of the error amplifier. The voltage at this point is connected to the

inverting input of the PWM comparator. A compensation network is required in order to

optimize the dynamic performance of the voltage mode control loop.

14

11

FB

The inverting input of the error amplifier. It serves as the output voltage feedback point

for the buck controller. It senses the output voltage through an external divider.

16

13

AGND

Analog signal gound.

1

14

SYNC/EN

The oscillator frequency of the SC4624 is set by FS when SYNC/EN is pulled and

held above 2V. Its synchronous mode is activated as SYNC/EN is driven by an exter-

nal clock. Its shutdown mode is invoked if SYNC/EN is pulled and held below 0.8V.

2

15

PGND1

Power ground.

3

16

PGND2

Power ground.

4

17

PH1

Switching nodes

5

18

PH2

Switching nodes

19

PH3

Switching nodes

7

20

PVIN2

Power supply voltage for high side MOSFETs.

THERMAL

PAD

Pad for heatsinking purposes only. Connect to ground plane using multiple vias. Not

electrically connected internally.