TC7135

TC7135 4-1/2 Digit A/D Converter Features Low Rollover Error: ±1 Count Max Nonlinearity Error: ±1 Count Max Reading for 0V Input True Polarity Indication at Zero for Null Detection Multiplexed BCD Data Output TTL-Compatible Outputs Differential Input Control Signals Permit Interface to UARTs and Microprocessors Blinking Display Visually Indicates Overrange Condition Low Input Current: 1pA Low Zero Reading Drift: 2µV/°C Auto-Ranging Supported with Overrange and Underrange Signals Available in PDIP and Surface-Mount Packages General Description The TC7135 4-1/2 digit A/D converter (ADC) offers 50ppm (1 part in 20,000) resolution with a maximum nonlinearity error of 1 count. An auto zero cycle reduces zero error to below 10µV and zero drift to 0.5µV/°C. Source impedance errors are minimized by a 10pA maximum input current. Rollover error is limited to ±1 count. Microprocessor based measurement systems are supported by BUSY, STROBE and RUN/HOLD control signals. Remote data acquisition systems with data transfer via UARTs are also possible. The additional control pins and multiplexed BCD outputs make the TC7135 the ideal converter for display or microprocessor based measurement systems. Functional Block Diagram SET VREF = 1V VREF IN 100k Ω –5V 1 2 V- TC7135 UNDERRANGE 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Clock Input 120kHz Applications Precision Analog Signal Processor Precision Sensor Interface High Accuracy DC Measurements Device Selecti...