Small Basic Isolated Delta-Sigma Modulator With ±50mV Input and Manchester-Encoded CMOS Interface

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.