ATSENSE301A-AU

Analog Front End (AFE) Overview

The ATSENSE301A-AU is a poly-phase analog front-end (AFE) device from Microchip Technology, designed for high-precision energy metering applications. It integrates seven simultaneously sampled Sigma-Delta A/D converters, a precision voltage reference, programmable current signal amplification, and an SPI interface. The device supports Class 0.2 standards compliance over a 3000:1 current range when paired with compatible microcontrollers. Key electrical parameters include a typical power consumption of less than 2.5 mW per channel at 3.3V operation, a 2.8V LDO regulator for analog functions, and a 102 dB dynamic range across its measurement channels.

Analog Front End (AFE) Feature Summary

• Integrates seven Sigma-Delta ADCs for simultaneous sampling of three voltages and four currents.
• Compliant with ANSI C12.20-2002 and IEC 62053-22 Class 0.2 standards.
• Features programmable gain amplifiers (x1, x2, x4, x8) for shunt, CT, and Rogowski coil inputs.
• Includes integrated SINC decimation filters with a typical output data rate of 16 kSps.

Analog Front End (AFE) Applications

• Three-phase, four-wire smart meters
• Poly-phase energy metering systems
• Data acquisition systems requiring high dynamic range

Analog Front End (AFE) Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to ensure correct package type and temperature grade. Confirm that the 'A' suffix denotes the standard voltage reference drift characteristics rather than the 'H' version with improved stability. Cross-reference the pinout requirements for the 32-lead TQFP package during PCB layout planning.

Analog Front End (AFE) Selection Notes

Select this component for poly-phase applications requiring up to seven synchronized measurement channels. Ensure the host MCU supports the required SPI interface and metrology library integration. Verify that the system design accommodates the external passive R-C anti-aliasing filters required for each ADC input to reject frequency images around the sampling clock.

Analog Front End (AFE) Part Context

This part belongs to the ATSENSE family, which includes single-phase (ATSENSE-101) and dual-phase (ATSENSE-201) variants. The ATSENSE-301 variant specifically provides the additional channels necessary for comprehensive poly-phase energy monitoring. It is designed to work in conjunction with Microchip's ATSAM4C device family for advanced metrology calculations.

Analog Front End (AFE) Replacement Considerations

For applications requiring higher voltage reference stability, consider the ATSENSE301HA-AU, which features a 10 ppm/°C temperature drift compared to the 50 ppm/°C typical drift of the standard version. Both parts share the same pinout and functional architecture.

Analog Front End (AFE) FAQ

How is the die temperature measured using the ATSENSE301A-AU?

The die temperature is measured by multiplexing the dedicated internal temperature sensor onto the tamper channel (ADC I0). The user must set the TEMPMEAS bit in the ADCI0 control register and average the ADC output over a minimum of 64 samples for repeatable results.

What is the maximum recommended input signal level for the analog inputs?

The maximum input signal level is typically ±0.25V to avoid leakage in the internal ESD protection devices connected to GNDA. For differential current inputs, the peak-to-peak voltage should not exceed 1Vpp.

Can the voltage reference drift be compensated in software?

Yes, for H-grade parts, factory-measured temperature drift data is stored in calibration registers (REF_TL, REF_TH, TEMP_TL, TEMP_TH). Users can implement a linear fit algorithm using these values to compensate for VREF drift over temperature.