The TC850 is a monolithic CMOS A/D converter （ADC） with resolution of 15-bits plus sign. It combines a chopper-stabilized buffer and integrator with a unique multiple-slope integration technique that increases conversion speed. The result is 16 times improvement in speed over previous 15-bit， monolithic integrating ADCs （from 2.5 conversions per second up to 40 per second）。 Faster conversion speed is especially welcome in systems with human interface， such as digital scales. The TC850 incorporates an ADC and a ?P-compatible digital interface. Only a voltage reference and a few， noncritical， passive components are required to form a complete 15-bit plus sign ADC. CMOS processing provides the TC850 with high-impedance， differential inputs. Input bias current is typically only 30 pA， permitting direct interface to sensors. Input sensitivity of 100 ?V per Least Significant bit （LSb） eliminates the need for precision external amplifiers. The internal amplifiers are auto-zeroed， ensuring a zero digital output， with 0V analog input. Zero adjustment potentiometers or calibrations are not required. The TC850 outputs data on an 8-bit， 3-state bus. Digital inputs are CMOS compatible while outputs are TTL/ CMOS compatible. Chip-enable and byte-select inputs， combined with an end-of-conversion output， ensures easy interfacing to a wide variety of microprocessors. Conversions can be performed continuously or on command. In Continuous mode， data is read as three consecutive bytes and manipulation of address lines is not required. Operating from ±5V supplies， the TC850 dissipates only 20 m?。 The TC850 is packaged in a 40-pin plastic or ceramic dual-in-line package （DIPs） and in a 44-pin plastic leaded chip carrier （PLCC）， surface-mount package.