TC7117CLW

ADCs/DACs - Special Purpose Overview

The TC7117CLW is a 3-1/2 digit CMOS Analog-to-Digital Converter (ADC) manufactured by Microchip Technology in a 44-pin PLCC package. It integrates seven-segment decoders, polarity and digit drivers, a voltage reference, and clock circuitry to directly drive common anode LED displays with an 8mA segment sink current. The device features a display hold function, auto-zero cycle for zero adjustment elimination, and high-impedance differential inputs with 10^12 Ω impedance. Electrical specifications include a typical noise of 15 µVp-p at 200mV full scale, linearity error within ±1 count, and operation from a single +5V supply or dual supplies.

ADCs/DACs - Special Purpose Feature Summary

• Directly drives common anode LED displays with 8mA per segment sinking capability
• Integrated low temperature drift internal reference (80 ppm/°C typical)
• Display Hold (HLDR) function allows indefinite reading retention while conversions continue
• High-impedance CMOS differential inputs offering 10^12 Ω input impedance and 1pA leakage

ADCs/DACs - Special Purpose Applications

• Thermometry systems
• Bridge readouts including strain gauges and load cells
• Digital meters for voltage, current, ohms, power, and pH
• Portable instrumentation powered by 9V batteries

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific ordering suffix 'CLW' corresponds to the 44-pin PLCC package and commercial temperature range (0°C to +70°C). Confirm that the 'C' designation indicates the standard 80 ppm/°C internal reference drift rather than the 'A' variant's 20 ppm/°C drift. Ensure the application design accounts for the direct LED drive current requirements and thermal dissipation characteristics inherent to this package type.

ADCs/DACs - Special Purpose Selection Notes

Select the TC7117CLW when a direct LED interface is required without external driver transistors. Choose this part over the TC7116 series if an LED display is preferred over LCD. Consider the TC7117ACLW if lower reference temperature drift (20 ppm/°C) is critical for the application. Ensure the system can accommodate the 8mA segment current draw and the specific pinout of the 44-pin PLCC package.

ADCs/DACs - Special Purpose Part Context

The TC7117CLW belongs to the TC7116/A/TC7117/A family of 3-1/2 digit ADCs. It is functionally identical to the TC7117 but packaged in PLCC instead of PDIP or PQFP. Unlike the TC7106/7107, the VREF- input is not available externally as it is tied internally to analog common. This family reduces linearity error to less than 1 count and eliminates the need for zero adjustment potentiometers through its auto-zero cycle.

ADCs/DACs - Special Purpose Replacement Considerations

Public confirmed substitute part numbers: TC7117ACPL (PDIP package, same electrical specs), TC7117CKW (PQFP package), TC7117IJL (CERDIP package). For lower drift requirements, consider TC7117ACLW. Verify that any replacement maintains the 44-pin PLCC footprint if board space is constrained.