TC7126ACKW

ADCs/DACs - Special Purpose Overview

The TC7126ACKW is a 3-1/2 digit CMOS Analog-to-Digital Converter (ADC) manufactured by Microchip Technology. It integrates seven-segment decoders, digit drivers, voltage reference, and clock circuits to directly drive Liquid Crystal Displays (LCDs). The device operates on a single 9V battery with typical power dissipation of 500µW. Key electrical specifications include a maximum linearity error of ±1 count, input leakage current of 1pA typical, and noise performance of 15µVP-P. It features an internal low-drift voltage reference and supports conversion rates up to 3 readings per second.

ADCs/DACs - Special Purpose Feature Summary

• Integrated 3-1/2 digit dual-slope ADC with direct LCD segment and backplane drivers
• Internal voltage reference with low temperature drift: 35ppm/°C typical for TC7126A
• High-impedance differential inputs with 1pA typical leakage current and 10^12Ω impedance
• Low power consumption: 500µW typical at 9V supply, suitable for portable battery operation

ADCs/DACs - Special Purpose Applications

• Thermometry systems
• Bridge readouts for strain gauges and load cells
• Digital panel meters for voltage, current, ohms, and pH measurement
• Digital scales and process monitors

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix 'KW' corresponds to the 44-pin PQFP package and commercial temperature range (0°C to +70°C) as defined in the device selection table. Confirm that the 'A' variant is required for the specified 35ppm/°C reference drift, as the standard TC7126 offers 80ppm/°C. Check current availability status as distribution channels may list end-of-life or limited stock conditions.

ADCs/DACs - Special Purpose Selection Notes

Select the TC7126ACKW when a 3-1/2 digit resolution with 0.05% accuracy is required for LCD-based instruments. Ensure the application utilizes a 9V battery or compatible supply within the 15V absolute maximum rating. For designs requiring industrial temperature ranges (-25°C to +85°C), the TC7126IPL variant must be selected instead. Verify external component values for integrating capacitors and resistors based on the desired conversion rate and full-scale input voltage.

ADCs/DACs - Special Purpose Part Context

The TC7126ACKW belongs to the TC7126/A family of integrating analog-to-digital converters. It serves as a drop-in replacement for legacy devices like the ICL7126, allowing system upgrades without changing external passive component values. The 'CKW' package code denotes the 44-pin PQFP form factor used in this specific part number.

ADCs/DACs - Special Purpose Replacement Considerations

The TC7126ACKW is functionally identical to the TC7126ACKW713 (tape and reel packaging) and the TC7126CKW (tray packaging). For industrial temperature requirements, the TC7126IPL or TC7126AIPL variants are appropriate substitutes.