Microchip Technology MCP3426A3-E/MS

Overview

MCP3426A3-E/MS from Microchip Technology is a 16-bit ΔΣ analog-to-digital converter with two differential input channels, on-board 2.048V ±0.05% voltage reference, programmable gain amplifier (x1/x2/x4/x8), and I²C interface supporting standard/fast/high-speed modes. It delivers 10 ppm INL, 15 SPS at 16-bit resolution, and operates from 2.7V to 5.5V supply across –40°C to +125°C - used in precision RTD-based temperature sensing and bridge transducer readout.

For engineers reviewing the MCP3426A3-E/MS datasheet, MCP3426A3-E/MS pinout, MCP3426A3-E/MS application, or MCP3426A3-E/MS equivalent, key selection criteria include its factory-programmed I²C address, MSOP-8 package with exposed thermal pad, self-calibrating offset/gain per conversion, and differential input full-scale range of ±2.048V/PGA.

Technical Context

The MCP3426A3-E/MS implements a delta-sigma modulator with integrated programmable gain amplifier and on-chip 2.048V reference, enabling high-accuracy DC measurements without external components. Its switched-capacitor input stage uses a 3.2 pF sampling capacitor and supports both one-shot (9 µA typical at 16-bit/1 SPS) and continuous (135 µA typical at 3V) conversion modes.

Each conversion includes automatic offset and gain calibration, ensuring stability over temperature and supply variation. The device uses an internal oscillator and supports I²C communication up to 3.4 MHz, with configuration register control of resolution (12/14/16-bit), channel selection (CH1/CH2), PGA gain, and conversion mode.

Key Specifications

Pinout & Package

The MCP3426A3-E/MS is housed in an 8-pin MSOP package with exposed thermal pad (EP), requiring connection to VSS for thermal and electrical integrity. Pin 1 is CH1+, pin 2 is CH1−, pin 3 is VSS, pin 4 is VDD, pin 5 is SDA, pin 6 is SCL, pin 7 is CH2+, and pin 8 is CH2−. The EP must be soldered to a VSS-coupled copper pour.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit delta-sigma ADC applications.

Compared with ADS1115IDGSR and MCP3421A0T-E/CH, the MCP3426A3-E/MS uniquely balances dual-channel capability, integrated reference, per-conversion calibration, and ultra-low one-shot current - making it optimal for space-constrained, high-accuracy dual-sensor systems where BOM count and calibration overhead must be minimized.

Availability

MCP3426A3-E/MS is available at Aetrix Electronics and suitable for precision temperature sensing, bridge transducer interfaces, thermocouple readout, and battery fuel gauging requiring stable component supply across industrial, test equipment, and medical device production lifecycles.

Supply support for MCP3426A3-E/MS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontrollers, analog, and Flash-IP solutions, serving industrial, automotive, communications, and consumer markets with high-reliability silicon and development tools.

The MCP342X series was designed specifically for high-accuracy, low-power sensor signal conditioning in space- and power-constrained embedded systems - emphasizing integrated references, self-calibration, and robust I²C interfacing.

FAQ

What is the factory-programmed I²C address of the MCP3426A3-E/MS?

The MCP3426A3-E/MS has a fixed I²C address of 0x68 (1101000b), determined by the 'A3' suffix per Microchip's addressing scheme. This address is laser-trimmed during manufacturing and cannot be modified via external pins or software - unlike the MCP3427/3428 which use Adr0/Adr1 pins for address selection. The MCP3426A3-E/MS simplifies system design by eliminating address conflict concerns in multi-device I²C buses.

Does the MCP3426A3-E/MS require external calibration for production use?

No, the MCP3426A3-E/MS performs automatic offset and gain calibration before every conversion, eliminating the need for external calibration routines or factory trim steps. This self-calibration uses the on-board 2.048V reference and internal circuitry to correct for temperature-induced drift and supply variation - ensuring consistent 10 ppm INL performance across –40°C to +125°C without host intervention or calibration coefficients.

How does the exposed thermal pad (EP) on the MCP3426A3-E/MS affect thermal performance?

The exposed thermal pad (EP) on the MCP3426A3-E/MS is electrically and thermally connected to VSS and must be soldered to a VSS-coupled copper pour on the PCB. In the MSOP-8 package, this reduces θJA from 211°C/W (no EP) to ~165°C/W (with proper EP layout), lowering junction temperature rise by up to 35°C at 135 µA continuous operation - critical for reliability in sealed enclosures or high-ambient-temperature applications.

Can the MCP3426A3-E/MS measure single-ended signals?

Yes, the MCP3426A3-E/MS supports single-ended measurement by connecting CH1− or CH2− to VSS, using CH1+ or CH2+ as the signal input. However, this sacrifices common-mode rejection and increases susceptibility to noise - the device's 105 dB CMRR and differential architecture are optimized for true differential inputs. Single-ended use is acceptable only when source impedance is low (<1 kΩ) and noise environment is benign.

What is the minimum recommended decoupling for the VDD pin of the MCP3426A3-E/MS?

The MCP3426A3-E/MS requires a minimum 0.1 µF X7R ceramic capacitor placed within 2 mm of the VDD pin and connected directly to VSS, plus a 10 µF tantalum capacitor in parallel for transient suppression. This dual-capacitor network suppresses high-frequency switching noise from the delta-sigma modulator and low-frequency current spikes during conversion - ensuring stable 16-bit accuracy and preventing POR resets during rapid I²C polling.