AMC1106x Small, High-Precision, Basic Isolated Delta-Sigma Modulators

1 Features

• ±50-mV input voltage range optimized for current measurement with shunt resistors
• Manchester coded or uncoded bitstream options
• Excellent DC performance for high-precision sensing on system level:
  • Offset error and drift: ±50 µV, ±1 µV/°C (max)
  • Gain error and drift: ±0.2%, ±40 ppm/°C (max)
• 3.3-V operation for reduced power dissipation on both sides of the isolation barrier
• System-level diagnostic features
• High electromagnetic field immunity
  (see the ISO72x Digital Isolator Magnetic-Field Immunity application report)
• Safety-related certifications:
  • 5657-V_PK basic isolation per DIN VDE V 0884-11: 2017-01
  • 4000-V_RMS isolation for 1 minute per UL1577
  • CAN/CSA No. 5A-component acceptance service notice
    and DIN EN 61010-1 end equipment standard

2 Applications

Shunt-resistor-based current sensing in 3-phase electricity meters

3 Description

The AMC1106 is a precision, delta-sigma (ΔΣ) modulator with the output separated from the input circuitry by a capacitive isolation barrier that is highly resistant to magnetic interference.

The input stage of the AMC1106 is optimized for direct connection to shunt resistors or other low voltage-level signal sources commonly used in multi-phase electricity meters to achieve excellent ac and dc performance. The device low input voltage range of ±50-mV allows use of small shunt resistor values to minimize power dissipation. Decimate the output bitstream of the AMC1106 with an appropriate digital filter. The MSP430F67x, TMS320F2807x, and TMS320F2837x microcontrollers, and the AMC1210 integrate these digital filters for seamless operation with the AMC1106.

On the high-side, the modulator is supplied by a
3.3-V or 5-V power supply (AVDD). The isolated digital interface operates from a 3.0-V, 3.3-V, or 5-V power supply (DVDD).

The AMC1106 is specified over the extended industrial temperature range of –40°C to +125°C.

1. For all available packages, see the orderable addendum at the end of the datasheet.