ICL7129ACQH-D

ADCs/DACs - Special Purpose Overview

The ICL7129ACQH-D is a 4-1/2 digit analog-to-digital converter (ADC) with integrated LCD drivers, manufactured by Analog Devices Inc. under the Maxim Integrated brand. It utilizes continuous integration technology to achieve ±20,000 count resolution on 2.00000V and 200.00mV ranges. The device features high-impedance differential inputs, true proportional operation, and automatic polarity detection. It operates within a supply voltage range of 6V to 14V and consumes approximately 1mA of current. The component is housed in a 44-pin PLCC package (16.59x16.59 mm) and supports an operating temperature range of 0°C to 70°C.

ADCs/DACs - Special Purpose Feature Summary

• 4-1/2 Digit Resolution: Provides ±19,999 counts with digital auto-zeroing for high accuracy without external compensation capacitors.
• Integrated LCD Drivers: Directly drives multiplexed LCD displays with 4 digits, decimal points, and annunciators.
• Low Input Bias Current: Maximum input bias current of 10pA minimizes measurement errors in high-impedance circuits.
• Auto-Ranging Capability: Includes overrange/underrange outputs and a 10:1 range switch input for automated measurement systems.

ADCs/DACs - Special Purpose Applications

• Precision Digital Voltmeters (DVM)
• Digital Panel Meters (DPM)
• Battery Operated Instrumentation
• Process Control Systems

ADCs/DACs - Special Purpose Procurement Notes

Verify the manufacturer designation, as this part number appears in listings from both Maxim Integrated and Analog Devices Inc. due to corporate acquisition history. Confirm the specific suffix 'D' indicates the lead-free or specific packaging variant if required by compliance standards. Check for RoHS compliance status, as older Maxim versions may contain lead. Ensure the 44-PLCC package dimensions match the target PCB footprint.

ADCs/DACs - Special Purpose Selection Notes

Select this component when a single-chip solution for high-precision DC voltage measurement is required. It is suitable for designs needing direct LCD interfacing without external decoders. Compare against the ICL7106/7107 series if lower resolution (3-1/2 digit) is acceptable for cost reduction. Ensure the application requires the specific 4-1/2 digit resolution and low noise characteristics provided by the continuous integration method.

ADCs/DACs - Special Purpose Part Context

The ICL7129 is part of the widely used 7129 family of ADCs, originally introduced by Intersil and later Maxim Integrated. It succeeded earlier models like the ICL7106 by offering higher resolution and integrated display driving capabilities. The MAX7129 is the equivalent part number often used interchangeably in documentation following Maxim's product line consolidation.

ADCs/DACs - Special Purpose Replacement Considerations

The MAX7129CPL is a documented equivalent in the same family. Verify pin compatibility between PLCC and DIP packages if substituting different form factors. Cross-reference with ICL7129 variants from Renesas Electronics for availability, noting potential differences in manufacturing origin.