TC7129
4-1/2 Digit Analog-to-Digital Converters with
On-Chip LCD Drivers
Features: General Description: The TC7129 is a 4-1/2 digit Analog-to-Digital Converter
(ADC) that directly drives a multiplexed Liquid Crystal
Display (LCD). Fabricated in high-performance, lowpower CMOS, the TC7129 ADC is designed specifically for high-resolution, battery-powered digital multimeter applications. The traditional dual-slope method
of A/D conversion has been enhanced with a successive integration technique to produce readings accurate to better than 0.005% of full-scale and resolution
down to 10 пЃV per count. Count Resolution: В±19,999
Resolution on 200 mV Scale: 10 пЃV
True Differential Input and Reference
Low Power Consumption: 500 пЃA at 9V
Direct LCD Driver for 4-1/2 Digits, Decimal Points,
Low Battery Indicator, and Continuity Indicator
Overrange and Underrange Outputs
Range Select Input: 10:1
High Common Mode Rejection Ratio: 110 dB
External Phase Compensation Not Required The TC7129 includes features important to multimeter
applications. It detects and indicates low battery condition. A continuity output drives an annunciator on the
display and can be used with an external driver to sound
an audible alarm. Overrange and underrange outputs,
along with a range-change input, provide the ability to
create auto-ranging instruments. For snapshot readings, the TC7129 includes a latch-and-hold input to
freeze the present reading. This combination of features …