The Intersil ICL7135 precision A/D converter, with its

multiplexed BCD output and digit drivers, combines dualslope conversion reliability with ±1 in 20,000 count accuracy

and is ideally suited for the visual display DVM/DPM market.

The 2.0000V full scale capability, auto-zero, and autopolarity are combined with true ratiometric operation, almost

ideal differential linearity and true differential input. All

necessary active devices are contained on a single CMOS

lC, with the exception of display drivers, reference, and a

clock.

The ICL7135 brings together an unprecedented combination

of high accuracy, versatility, and true economy. It features

auto-zero to less than 10μV, zero drift of less than 1μV/oC,

input bias current of 10pA (Max), and rollover error of less

than one count. The versatility of multiplexed BCD outputs is

increased by the addition of several pins which allow it to

operate in more sophisticated systems. These include

STROBE, OVERRANGE, UNDERRANGE, RUN/HOLD and

BUSY lines, making it possible to interface the circuit to a

microprocessor or UART.

Features

• Accuracy Guaranteed to ±1 Count Over Entire ±20000

Counts (2.0000V Full Scale)

• Guaranteed Zero Reading for 0V Input

• 1pA Typical Input Leakage Current

• True Differential Input

• True Polarity at Zero Count for Precise Null Detection

• Single Reference Voltage Required

• Overrange and Underrange Signals Available for AutoRange Capability

• All Outputs TTL Compatible

• Blinking Outputs Gives Visual Indication of Overrange

• Six Auxiliary Inputs/Outputs are Available for Interfacing to

UARTs, Microprocessors, or Other Circuitry

• Multiplexed BCD Outputs

• Pb-Free Plus Anneal Available (RoHS Compliant)