TC7135

1 TC7135 4-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTER FEATURES s s s s s s s s s s s s s s Low Roll-Over Error ......................... ±1 Count Max Guaranteed Nonlinearity Error ........ ±1 Count Max Guaranteed Zero 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 µProcessors Auto-Ranging Supported With Overrange and Underrange Signals Blinking Display Visually Indicates Overrange Condition Low Input Current ............................................. 1 pA Low Zero Reading Drift ............................... 2 µV/°C Interfaces to TC7211A (LCD) and TC7212A (LED) Display Drivers Available in DIP and Surface-Mount Packages GENERAL DESCRIPTION The TC7135 4-1/2 digit analog-to-digital converter (ADC) offers 50 ppm (1 part in 20,000) resolution with a maximum nonlinearity error of 1 count. An auto-zero cycle reduces zero error to below 10 µV and zero drift to 0.5 µV/°C. Source impedance errors are minimized by a 10 pA maximum input current. Roll-over error is limited to ±1 count. By combining the TC7135 with a TC7211A (LCD) or TC7212A (LED) driver, a 4-1/2 digit display DVM or DPM can be constructed. Overrange and underrange signals support automatic range switching and special display blanking/flashing applications. Microprocessor-based measurement systems are supported by BUSY, STROBE, and RUN/HOLD control signals. Remote data acquisition s...