Datasheet TC7650 (Microchip) - 2

TC7650 General Description
The TC7650 nulling scheme corrects both DC VOS errors and V The TC7650 CMOS chopper stabilized operational OS drift errors with temperature. A nulling amplifier alternately corrects its own V amplifier practically removes offset voltage error terms OS errors and the main amplifier V from system error calculations. The 5V maximum V OS error. Offset nulling voltages are OS stored on two user supplied external capacitors. The specification, for example, represents a 15 times capacitors connect to the internal amplifier V improvement over the industry standard OP07E. The OS null points. The main amplifier input signal is never 50nV/°C offset drift specification is over 25 times lower switched. Switching spikes are not present at the than the OP07E. The increased performance elimi- TC7650 output. nates VOS trim procedures, periodic potentiometer adjustment and the reliability problems caused by dam- The 14-pin dual-in-line package (DIP) has an external aged trimmers. oscillator input to drive the nulling circuitry for optimum noise performance. Both the 8 and 14-pin DIPs have The TC7650 performance advantages are achieved an output voltage clamp circuit to minimize overload without the additional manufacturing complexity and recovery time. cost incurred with laser or "zener zap" VOS trim tech- niques.
Functional Block Diagram
Output Clamp 14-Pin DIP Only Output Clamp INT/EXT Circuit Oscillator EXT CLK IN CLK OUT Main Amplifier A B Inputs Output NULL CB Intermod Compensation CA B B B A Null Amplifier
TC7650
A Null *CRETN * For 8-Pin DIP, connect to Vss DS21463C-page 2  2001-2012 Microchip Technology Inc.