ICL7135 A to D converter with BCD Output

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.

ICL7135 Device Information

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.
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 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

See related delabs projects

• Auto ranging 4-1/2 Digit Digital Voltmeter
• ICL7135 to Printer port 4-1/2 DVM.