DESCRIPTION OF PIN FUNCTIONS

DATA

Serial programming data is input to the TRAC via this pin. Each TRAC cell contains

a 3-bit shift register that allows each cell to be programmed to the required analog

function.

RESET

Active low - The pin resets all on-chip shift registers to the logic zero state, which sets

all TRAC cells to the OFF function. The pin should be held high while the device is

being programmed and when the analog functions are in use.

PD

Active low - The pin switches off the bias generators to the analog cells, which turns

off the supply current to all the TRAC cells. This does not influence the programming

of the cells so this feature can be used to reduce power consumption for applications

that have a standby mode. The pin should be held high while the device is being

programmed and when the analog functions are in use. This pin is permanently held

CLOCK

Used to clock in the serial data to program the TRAC device. The on-chip shift registers

are positive edge triggered.

DOUT

This pin is the serial data output from cell 20 on the TRAC device. This is used for

validation of programming of the TRAC device. This pin also allows two or more

TRAC devices to be connected in a serial architecture. This is done by connecting the

DOUT pin of the first TRAC device to the DATA pin of the second TRAC device, and

connecting the CLOCK pins.

CLCR

Clock Clear. When the TRAC device is used in stand alone applications CLCR is used

as a control pin. It allows the downloading circuitry to be switched off when the

programming serial data from the EEPROM is complete.

IO3..IO22

These are the analog inputs / outputs for cells 1 to 20.

IO1,IO2

These are the analog inputs for cells 1 and 2.

TRAC positive supply rail (+3V)

Analog Ground

TRAC negative supply rail (-2V) - this will also be the system ground

TRAC020LH

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