Microchip Technology MCP3426A1T-E/MS

Overview

MCP3426A1T-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 15 SPS at 16-bit resolution, 10 ppm INL, and operates from 2.7V to 5.5V across –40°C to +125°C - used in precision RTD-based temperature sensing and bridge transducer readout.

For engineers reviewing the MCP3426A1T-E/MS datasheet, MCP3426A1T-E/MS pinout, MCP3426A1T-E/MS application, or MCP3426A1T-E/MS equivalent, key selection criteria include differential channel count, self-calibrating offset/gain per conversion, PGA-configurable input range, low-power one-shot mode (0.56 µA at 12-bit), and MSOP-8 package compatibility with space-constrained industrial sensor nodes.

Technical Context

The MCP3426A1T-E/MS implements a delta-sigma modulator with integrated sinc filter, on-chip oscillator, and automatic per-conversion offset/gain calibration - eliminating need for external calibration circuitry. Its switched-capacitor front-end uses a 3.2 pF sampling capacitor and supports both differential and single-ended inputs per channel.

I²C communication includes configurable address (factory-programmed for MCP3426), support for 100 kHz / 400 kHz / 3.4 MHz modes, and open-drain SDA/SCL pins requiring external pull-ups. The device defaults to 12-bit continuous conversion on CH1 with PGA = 1 at power-on reset.

Key Specifications

Pinout & Package

The MCP3426A1T-E/MS is housed in an 8-pin MSOP package (3.0 mm × 4.9 mm, 0.65 mm pitch) with exposed thermal pad (EP) internally connected to VSS and requiring PCB connection to ground plane for thermal and noise performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-accuracy, multi-channel ΔΣ ADC applications.

Compared with ADS1115IDGSR and MCP3424-E/SL, the MCP3426A1T-E/MS uniquely combines factory-fixed I²C address, integrated reference, and MSOP-8 footprint - optimizing for minimal component count and layout simplicity in dual-sensor industrial nodes.

Availability

MCP3426A1T-E/MS is available at Aetrix Electronics and suitable for precision temperature monitoring, industrial weigh scale systems, and battery fuel gauge designs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MCP3426A1T-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 devices, and Flash-IP solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The MCP342X series was designed specifically for high-accuracy, low-power sensor signal acquisition in space- and energy-constrained embedded systems - emphasizing integration, calibration autonomy, and robust I²C interoperability.

FAQ

What is the factory-programmed I²C address of the MCP3426A1T-E/MS?

The MCP3426A1T-E/MS has its I²C address permanently programmed at the factory and cannot be modified via external pins. Its default 7-bit address is 0x68 (1101000b) when A0 = low, confirmed in Microchip DS22226A Section 5.3.1. This fixed addressing simplifies system design where only one MCP3426A1T-E/MS is used on the bus, avoiding address collision concerns during firmware initialization.

Does the MCP3426A1T-E/MS support single-ended input configurations?

Yes, the MCP3426A1T-E/MS supports single-ended operation: tie CH1− or CH2− to VSS and apply the signal to CH1+ or CH2+, respectively. As documented in DS22226A Section 3.1, this configuration maintains full 16-bit resolution and self-calibration but reduces common-mode rejection. Input voltage must remain within VSS−0.3V to VDD+0.3V, and PGA scaling still applies to the measured differential voltage.

How does the on-board oscillator affect timing accuracy in the MCP3426A1T-E/MS?

The MCP3426A1T-E/MS uses an internal oscillator whose drift is specified at ±0.5% over –40°C to +125°C (DS22226A Figure 2-10). This impacts absolute data rate accuracy but not conversion integrity - since offset/gain calibration occurs per conversion, timing variation does not degrade INL or gain error. For applications requiring precise time-stamping, an external clock source is not supported; system-level timestamping must compensate for oscillator tolerance.

Can the MCP3426A1T-E/MS measure beyond ±2.048V differentially?

No - the MCP3426A1T-E/MS cannot directly measure differential inputs exceeding ±2.048V, even with PGA = 1. Its internal 2.048V reference defines the absolute full-scale range: |CHn+ − CHn−| × PGA must be ≤ 2.048V. Exceeding this causes saturation (all 0s or all 1s except sign bit). To measure wider ranges, an external resistive divider must scale the input before connection, as shown in DS22226A Figure 6-7, preserving common-mode rejection via matched components.

What thermal management is required for the MCP3426A1T-E/MS in MSOP-8 package?

The MCP3426A1T-E/MS in MSOP-8 has θJA = 211°C/W (DS22226A page 7). To maintain junction temperature ≤125°C at 125°C ambient, power dissipation must stay below 0.95 mW. With max IDD = 180 µA at 5.5V (1 mW), thermal relief is essential: the exposed thermal pad (EP) must be soldered to a minimum 100 mm² copper pour connected to VSS. Without EP grounding, temperature rise exceeds safe limits under continuous operation.