GENERAL DESCRIPTION
The TC7109A is a 12-bit plus sign, CMOS low-power analog-to-digital converter (ADC). Only eight passive components and a crystal are required to form a complete dual-slope integrating ADC.
The improved VOH source current TC7109A has features that make it an attractive per-channel alternative to analog multiplexing for many data acquisition applications. These features include typical input bias current of 1pA drift of less than 1µV/°C, input noise typically 15µVP-P, and auto-zero. True differential input and reference allow measurement of bridge-type transducers such as load cells, strain gauges, and temperature transducers.

FEATURES
■ Zero-Integrator Cycle for Fast Recovery From Input Overloads
■ Eliminates Cross -Talk in Multiplexed Systems
■ 12-Bit Plus Sign Integrating A/D Converter With Overrange Indication
■ Sign Magnitude Coding Format
■ True Differential Signal Input and Differential Reference Input
■ Low Noise ............................................ 15 µVP-P Typ
■ Input Current .............................................. 1 pA Typ
■ No Zero Adjustment Needed
■ TTL-Compatible, Byte-Organized Tri-State Outputs
■ UART Handshake Mode for Simple Serial Data Transmission