ZL2103

FN6966 Rev 5.00

Page 3 of 28

May 3, 2011

Pin Configuration

ZL2103

(36 LD QFN)

TOP VIEW

VSET

SA

SCL

SDA

SALRT

FC

PG

SYNC

DGND

ZL2103

36-Pin QFN

6 x 6 mm

SW

SW

SW

SW

SW

PGND

VDDP

SW

BST

Exposed Paddle

Connect to SGND

1

2

3

4

5

6

7

8

9

27

26

25

24

23

22

21

20

19

FIGURE 4.

Pin Descriptions

PIN

LABEL

TYPE

(Note 1)

DESCRIPTION

1

PG

O

Power-good. This pin transitions high 100ms after output voltage stabilizes within regulation band.

Selectable open drain or push-pull output. Factory default is open drain.

2

DGND

PWR

Digital ground. Common return for digital signals. Connect to low impedance ground plane.

3SYNC

I/O, M

(Note 2)

Clock synchronization pin. Used to set switching frequency of internal clock or for synchronization to

external frequency reference.

4

VSET

I, M

5

SA

I, M

Serial address select pin. Used to assign unique SMBus address to each IC.

6

SCL

I/O

Serial clock. Connect to external host interface.

7

SDA

I/O

Serial data. Connect to external host interface.

8

SALRT

O

Serial alert. Connect to external host interface if desired.

9

FC

I, M

Loop compensation select pin. Used to set loop compensation.

10

CFG

I, M

Configuration pin. Used to control the SYNC pin, sequencing and enable tracking.

11

SS

I, M

Soft-start pin. Used to set the ramp delay and ramp time, sets UVLO and configure tracking.

12

VTRK

I

Track sense pin. Used to track an external voltage source.

13

VSEN

I

Output voltage positive feedback sensing pin.

14

SGND

PWR

Common return for analog signals. Connect to low impedance ground plane.

15, 16, 17,

18, 19

PGND

PWR

Power ground. Common return for internal switching MOSFETs. Connect to low impedance ground plane.

20, 21, 22,

23, 24, 25

SW

I/O

Switching node (level-shift common).

26

BST

PWR

Bootstrap voltage for level-shift driver (referenced to SW).

27, 28, 29

VDDP

PWR

Bias supply voltage for internal switching MOSFETs (return is PGND).

30

VDDS

PWR

IC supply voltage (return is SGND).