10

FN6421.0

July 17, 2007

Pin Description

Potentiometers Pins

RH and RL

The high (RH) and low (RL) terminals of the ISL22313 are

equivalent to the fixed terminals of a mechanical

potentiometer. RH and RL are referenced to the relative

position of the wiper and not the voltage potential on the

terminals. With WR set to 255 decimal, the wiper will be

closest to RH, and with the WR set to 0, the wiper is closest

to RL.

RW

RW is the wiper terminal, and it is equivalent to the movable

terminal of a mechanical potentiometer. The position of the

wiper within the array is determined by the WR register.

Bus Interface Pins

Serial Data Input/Output (SDA)

interface. It receives device address, operation code, wiper

rising edge of the serial clock SCL, and it shifts out data after

each falling edge of the serial clock.

SDA requires an external pull-up resistor, since it is an open

drain input/output.

Serial Clock (SCL)

requires an external pull-up resistor, since it is an open drain

input.

FIGURE 11. TC FOR RHEOSTAT MODE IN ppm

FIGURE 12. FREQUENCY RESPONSE (1MHz)

FIGURE 13. MIDSCALE GLITCH, CODE 7Fh TO 80h

FIGURE 14. LARGE SIGNAL SETTLING TIME

0

100

200

300

400

500

16

66

116

166

216

TAP POSITION (DECIMAL)

50k

10k

OUTPUT

INPUT

WIPER AT MID POINT (POSITION 80h)

SCL

WIPER

CS

WIPER UNLOADED,

MOVEMENT FROM 0h to FFh

ISL22313