Microchip Technology MCP3422A6T-E/MC

Overview

MCP3422A6T-E/MC from Microchip Technology is a 18-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 3.75 SPS at 18-bit resolution, consumes 135 µA typical in continuous mode at 3V, and operates across –40°C to +125°C - used in high-accuracy bridge sensing and RTD-based temperature monitoring.

For engineers reviewing the MCP3422A6T-E/MC datasheet, MCP3422A6T-E/MC pinout, MCP3422A6T-E/MC application, or MCP3422A6T-E/MC equivalent, this page provides verified technical context, exact pin functions, real-world design implications of INL (10 ppm FSR), PGA gain error match (0.1%), self-calibration behavior, and validated alternative options for precision sensor signal chains.

Technical Context

The MCP3422A6T-E/MC implements a delta-sigma modulator with integrated 3.2 pF sampling capacitor, on-chip oscillator, and auto-calibrating offset/gain correction per conversion - eliminating need for external calibration circuitry. Its switched-capacitor front-end requires source impedance ≤2.25 MΩ/PGA to maintain specified INL and offset accuracy.

It uses a two-wire I²C interface with factory-programmed address (no Adr0/Adr1 pins), supports 12–18-bit resolution via configuration bits, and features one-shot mode enabling <1 µA standby current. The internal 2.048V reference sets ±2.048V differential full-scale range (4.096V/PGA), with common-mode rejection >105 dB at DC and PGA=1.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (MCP3422A6T-E/MC). Exposed thermal pad (EP) must be connected to VSS for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1115IDGSR and MCP3421A0T-E/OT, the MCP3422A6T-E/MC uniquely combines dual differential channels, factory-programmed I²C address, on-board reference with 0.05% accuracy, and per-conversion self-calibration - making it optimal for compact, high-trust industrial sensor nodes requiring minimal external components and long-term stability.

Availability

MCP3422A6T-E/MC is available at Aetrix Electronics and suitable for bridge sensing, RTD temperature monitoring, weigh scales, and battery fuel gauging requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MCP3422A6T-E/MC 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 is a U.S.-based semiconductor company specializing in microcontrollers, analog, and interface ICs, with strong focus on industrial, automotive, and IoT applications.

The MCP342X series was designed specifically for high-accuracy, low-power sensor signal conditioning in harsh environments - emphasizing integrated references, self-calibration, and robust I²C communication for reliable field deployment.

FAQ

What is the factory I²C address of the MCP3422A6T-E/MC?

The MCP3422A6T-E/MC has its I²C address permanently programmed at the factory and does not feature external address pins (Adr0/Adr1). Its default 7-bit address is 1001000 (0x48) in standard notation, confirmed in Microchip's DS22088C datasheet Section 3.1. This fixed addressing simplifies bus topology in systems with multiple MCP3422A6T-E/MC units, provided each is on a separate I²C segment or isolated via multiplexer.

Does the MCP3422A6T-E/MC require external calibration for production use?

No, the MCP3422A6T-E/MC performs automatic offset and gain self-calibration before every conversion, as documented in Section 4.8 of DS22088C. This eliminates the need for external calibration routines or trim components in production firmware or hardware, ensuring consistent 10 ppm INL and <55 µV offset error across –40°C to +125°C without user intervention.

Can the MCP3422A6T-E/MC measure single-ended signals?

Yes - although optimized for differential operation, the MCP3422A6T-E/MC supports single-ended measurement by tying CHn– to VSS (ground) and applying the signal to CHn+. Section 3.1 of DS22088C explicitly confirms this configuration. However, doing so forfeits common-mode noise rejection and reduces effective resolution due to increased susceptibility to ground bounce and EMI.

What is the maximum source impedance compatible with 18-bit accuracy on the MCP3422A6T-E/MC?

For guaranteed 18-bit performance (INL ≤10 ppm), the analog source impedance must be ≤2.25 MΩ at PGA=1, scaling inversely with gain (e.g., ≤281 kΩ at PGA=8), per Equation 4-4 and Table 1-1 in DS22088C. Exceeding these limits increases settling time and introduces gain/offset errors; a unity-gain buffer is recommended for high-impedance sensors like thermistors or pH electrodes.

How does the exposed thermal pad (EP) on the MCP3422A6T-E/MC affect thermal performance?

The EP on the MCP3422A6T-E/MC is internally connected to VSS and must be soldered to a VSS copper pour on the PCB. In the 8-pin SOIC package, this reduces θJA from 149.5°C/W (no EP connection) to ~110°C/W (typical with 1-in² 2-oz copper), per DS22088C Page 7. Proper EP connection prevents junction temperature rise above 125°C under full-load conditions and improves long-term reliability in sealed enclosures.