PIN NUMBER

PIN NAME

PIN TYPE

PIN FUNCTION

1

VSSB

S

Ground for DC/DC boost and reference circuits; chip substrate

2

SS

I

Soft-start input; the capacitor connected to this pin sets the current limited start time

3

FBB

I

4

VDDB

S

Positive supply input for DC/DC boost circuits

5

LX

O

Boost regulator inductor drive connected to drain of internal NFET

6

LX

O

Boost regulator inductor drive connected to drain of internal NFET

7

LX

O

Boost regulator inductor drive connected to drain of internal NFET

8

DRVN

O

9

VDDN

S

10

FBN

I

11

VSSP

S

Negative supply pin for both the positive and negative charge pumps

12

FBP

I

13

VDDP

S

14

DRVP

O

15

PGND

O

Power ground, connected to source of internal NFET

16

PGND

O

Power ground, connected to source of internal NFET

17

VREF

I

Voltage reference for charge pump circuits; decouple to ground

18

ENBN

I

active high

19

ENP

I

20

ROSC

I

Connected to an external resistor to ground; sets the switching frequency of the DC/DC

boost

4

FN7335.3

February 4, 2005

EL7583