© 2011 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FAN23SV04T • Rev. 1.0.1

4

Pin Configuration

9

34

17

26

18

27

10

8

7

2

3

6

5

4

16

15

14

13

12

11

19

20

21

22

23

24

25

33

28

29

30

31

32

PVIN

PVIN

SW

SW

SW

SW

SW

SW

FB

NC

NC

NC

VDDQ

EN

FREQ

SS

AGND

(P1)

PVIN

(P2)

SW

(P3)

1

PVIN

PVIN

SW

SW

SW

SW

SW

SW

FB

NC

NC

NC

VDDQ

EN

FREQ

SS

1

9

10

27

26

18

17

34

2

3

8

7

4

5

6

28

29

30

31

32

33

19

20

21

22

23

24

25

11

16

15

14

13

12

Figure 4. Bottom View

Figure 5. Top View

Pin Definitions

Name

Pad / Pin

Description

PVIN

P2; 5-11

Power input for the power stage.

VIN

1

Power input to the linear regulator; used in the modulator for input voltage feed-forward.

PVCC

25

Power output of the linear regulator; directly supplies power for the low-side gate driver

and boot diode. Can be connected to VIN and PVIN for operation from 5 V rail.

VCC

26

Power supply input for the controller.

PGND

18-21

Power ground for the low-side power MOSFET and for the low-side gate driver.

AGND

P1; 4, 23

Analog ground for the analog portions of the IC and for substrate.

SW

P3; 2, 12-17, 22 Switching node; junction between high-and low-side MOSFETs.

BOOT

3

Supply for high-side MOSFET gate driver. A capacitor from BOOT to SW supplies the

charge to turn on the N-channel high-side MOSFET. During the freewheeling interval

(low-side MOSFET on), the high-side capacitor is recharged by an internal diode

connected to PVCC.

ILIM

24

Current limit. A resistor between ILIM and SW sets the current-limit threshold.

FB

27

Output voltage feedback to the modulator.

EN

29

Enable input to the IC. Pin must be driven logic high to enable, or logic low to disable.

SS

30

Soft-Start input to the modulator

VDDQ

31

External reference input to the modulator. The modulator regulates to half of the voltage

at the VDDQ pin.

FREQ

32

On-time and frequency programming pin. Connect a resistor between FREQ and AGND

to program on-time and switching frequency.

NC

28, 33-34

Leave pin open or connect to AGND.