SMS47 datasheet(7/19 Pages) SUMMIT

7 / 19 page

2087 1.0 04/11/05

SMS47

SUMMIT MICROELECTRONICS, Inc.

Preliminary Information

A1,A2 (6, 7)

A1 and A2 are the address inputs. When addressing the

SMS47 configuration registers the address inputs distin-

guish which one of four possible devices sharing the

common bus is being addressed.

SDA (9)

SDA is the serial data input/output pin. It should be tied to

VDD_CAP through a pull-up resistor.

SCL (10)

SCL is the serial clock input. It should be tied to VDD_CAP

through a pull-up resistor.

PUP#1, PUP#2, PUP#3 (4, 5, 13)

These are the power-up permitted (PUP) active low open

drain outputs. The PUP pins are used when the SMS47 is

programmed to provide the cascade sequencing of LDOs

or DC/DC converters (see Figures 1 and 5 for illustra-

tions of cascading). Each delay is independently enabled

and programmable for its duration (configuration register

7). If all PUP# outputs are enabled the order of events

would be as follows: V0 above threshold then delay to

PUP#1 turning on; V1 above threshold then delay to PUP#2

turning on; V2 above threshold then delay to PUP#3 turning

on. The delays are programmable.

PIN DESCRIPTIONS (CONTINUED)

SMS47 Datasheet(PDF) 7 Page - Summit Microelectronics, Inc.