MCP3426A6T-E/MC

Analog To Digital Converters (ADC) Overview

The MCP3426A6T-E/MC is a 16-bit, dual-channel Delta-Sigma Analog-to-Digital Converter (ADC) manufactured by Microchip Technology. It features an integrated I²C interface and an on-board 2.048V voltage reference with ±0.05% accuracy. The device supports differential inputs with a full-scale range of -VREF to +VREF and includes a programmable gain amplifier (PGA) with gains of 1, 2, 4, or 8. Key electrical specifications include a maximum Integral Non-Linearity (INL) of 10 ppm of Full Scale Range and a typical gain error of 0.1%. It operates from a single 2.7V to 5.5V supply and offers data rates of 15 SPS (16-bit), 60 SPS (14-bit), and 240 SPS (12-bit).

Analog To Digital Converters (ADC) Feature Summary

• 16-bit resolution with differential inputs and self-calibration for offset and gain errors.
• Integrated 2.048V voltage reference (±0.05% accuracy) and Programmable Gain Amplifier (PGA) with gains of x1, x2, x4, or x8.
• I²C serial interface supporting Standard (100 kHz), Fast (400 kHz), and High-Speed (3.4 MHz) modes.
• Low power consumption: 135 µA typical in continuous conversion mode; down to 0.56 µA in one-shot standby mode at 12-bit resolution.

Analog To Digital Converters (ADC) Applications

• Portable instrumentation and consumer goods.
• Temperature sensing using RTDs, thermistors, and thermocouples.
• Bridge sensing for pressure, strain, and force measurements.
• Weigh scales and battery fuel gauges.
• Factory automation equipment.

Analog To Digital Converters (ADC) Procurement Notes

Verify the ordering suffix 'T' indicates tape-and-reel packaging and 'MC' denotes the specific package type as defined by Microchip. Confirm that the 'E' suffix corresponds to the extended temperature range (-40°C to +125°C). Ensure compatibility with the required I²C address configuration, as the MCP3426 has factory-programmed addresses unlike the user-configurable MCP3427/8.

Analog To Digital Converters (ADC) Selection Notes

Select this component when high accuracy (16-bit) and low noise are required for dual-channel differential signals. The internal PGA allows amplification of weak signals without external components. Choose between One-Shot and Continuous conversion modes based on power constraints; One-Shot mode significantly reduces current draw during idle periods. Ensure the input source impedance is low to prevent degradation of INL and offset performance due to the switched-capacitor input structure.

Analog To Digital Converters (ADC) Part Context

The MCP3426A6T-E/MC belongs to the MCP342X family, which also includes the MCP3427 (2 channels, configurable I²C address) and MCP3428 (4 channels, configurable I²C address). All devices share identical electrical characteristics, including the ADC architecture, reference voltage, and PGA capabilities. The primary distinction lies in the number of input channels and the method of I²C address selection.

Analog To Digital Converters (ADC) Replacement Considerations

Direct pin-compatible replacements within the same package may include other variants from the MCP3426 series with different suffixes indicating package or temperature variations. For multi-channel needs, the MCP3427 or MCP3428 can be considered if additional channels or address configurability are required, though pin counts may differ for the 4-channel variant.

Analog To Digital Converters (ADC) FAQ

How does the device handle input voltages exceeding the full-scale range?

If the differential input voltage multiplied by the PGA gain exceeds the internal reference voltage (±2.048V), the output code will saturate. Positive saturation results in a code of 011...111, and negative saturation results in 100...000. The code remains locked at these values even if the input voltage increases further.

What is the impact of source impedance on conversion accuracy?

The device uses a switched-capacitor input stage with a sampling capacitor of approximately 3.2 pF. High source impedance can degrade performance by increasing the time required to charge the sampling capacitor, potentially leading to increased offset, gain, and Integral Non-Linearity (INL) errors. An operational amplifier with low output impedance is recommended for high-impedance sources.

Does the MCP3426 support user-configurable I²C addresses?

No, the I²C address bits for the MCP3426 are programmed at the factory during production. Unlike the MCP3427 and MCP3428, which have external address selection pins (Adr0 and Adr1), the MCP3426 does not provide user-configurable address options.