ZL9117M

2

FN7914.1

October 21, 2011

Pin Configuration

ZL9117M

(21 LD QFN)

TOP VIEW

SDA

VSET

VTRK

FB+

FB-

PGND

V25

VDD

VDRV

SW

VIN

PGND

VOUT

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

Pin Descriptions

PIN

LABEL

TYPE

DESCRIPTION

1SDA

I/O

Serial data.

2SCL

I/O

Serial clock.

3

SA

I

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

4

SYNC

I/O

Clock synchronization. Used for synchronization to external frequency reference.

5

PG

O

Power-good output.

6

EN

I

Enable input (factory setting active high). Pull up to enable PWM switching and pull down to disable PWM switching.

7

DDC

I/O

Digital-DC bus (open drain). Interoperability between Zilker Labs modules.

8

VR

PWR Internal 5V reference used to power internal drivers. Connect 4.7μF bypass capacitor to this pin.

9

SGND

PWR Signal ground. Connect to low impedance ground plane.

10

PGND

PWR Power ground. Connect to low impedance ground plane.

11

V25

PWR Internal 2.5V reference used to power internal circuitry. Connect 4.7μF bypass capacitor to this pin.

12

VDD

PWR Input supply voltage for controller. Connect 4.7μF bypass capacitor to this pin.

13

VDRV

PWR Power supply for internal FET drivers. Connect 10μF bypass capacitor to this pin.

14 (epad)

SW

PWR Drive train switch node

15 (epad)

VIN

PWR Power supply input FET voltage.

16 (epad)

PGND

PWR Power ground. Connect to low impedance ground plane.

17 (epad)

VOUT

PWR Power supply output voltage. Output voltage from PWM.

18

FB-

I

Output voltage feedback. Connect to load return of ground regulation point.

19

FB+

I

Output voltage feedback. Connect to output regulation point.

20

VTRK

I

Tracking sense input. Used to track an external voltage source.

21

VSET

I