TC7117ACLW

ADCs/DACs - Special Purpose Overview

The TC7117ACLW is a 3-1/2 digit CMOS Analog-to-Digital Converter (ADC) manufactured by Microchip Technology. It integrates seven-segment decoders, polarity and digit drivers, a voltage reference, and clock circuitry to drive common anode LED displays directly with an 8mA segment current. The device features a low drift internal reference (20 ppm/°C typical), display hold functionality, and high-impedance differential inputs with 10^12 Ω impedance. It operates on a single +5V supply or ±5V supplies, achieving 15 µVp-p noise performance and less than 1 count linearity error in a 44-pin PLCC package.

ADCs/DACs - Special Purpose Feature Summary

• Directly drives common anode LED displays with 8mA per segment sink current
• Integrated low temperature drift internal reference (20 ppm/°C typical)
• High-impedance CMOS differential inputs offering 10^12 Ω input impedance
• Display Hold function allows indefinite retention of the displayed reading

ADCs/DACs - Special Purpose Applications

• Thermometry systems
• Bridge readouts for 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 'A' designation indicates the improved 20 ppm/°C internal reference temperature coefficient compared to the standard TC7117 variant. Ensure compatibility with common anode LED displays requiring direct drive capabilities.

ADCs/DACs - Special Purpose Selection Notes

Select this component when direct LED driving is required without external buffer transistors. The TC7117ACLW is suitable for applications needing a 200mV or 2V full-scale range with ratiometric measurements. Consider the 44-pin PLCC package constraints for PCB layout. Verify that the system can accommodate the 100kΩ resistor and 100pF capacitor required for the 48kHz oscillator frequency to achieve 3 readings per second.

ADCs/DACs - Special Purpose Part Context

The TC7117ACLW belongs to the TC7116/A/TC7117/A family of 3-1/2 digit ADCs. It is functionally identical to the TC7117CLW but features an enhanced internal reference with lower temperature drift (20 ppm/°C vs. 80 ppm/°C). Unlike the TC7107, which requires negative supplies for dual-rail operation in some configurations, the TC7117A is optimized for single +5V or ±5V operation with integrated backplane logic elimination for LED variants.

ADCs/DACs - Special Purpose Replacement Considerations

The TC7117CLW is a direct functional substitute within the same package, differing only in the internal reference temperature coefficient (80 ppm/°C vs. 20 ppm/°C). Other package options include the TC7117CKW (44-Pin PQFP) and TC7117CPL (40-Pin PDIP). External reference usage may mitigate drift differences between these variants.