The Intersil ICL7135 precision A/D converter, with its multiplexed BCD output and digit drivers, combines dual-slope 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 auto-polarity 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.

• 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 Auto-Range 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 Available (RoHS Compliant)