Chipset Eliminates Current Transformers In Polyphase Meters

Promising to lower the BOM for polyphase energy meters, the MAXQ3108 and DS8102 chipset replace three high-cost current transformers with three low-cost shunts. The DS8102 integrates two second-order, delta-sigma modulators with programmable gains up to 32x. Encoded into a single bit stream, the modulator outputs minimize isolation and data-coupling costs. For data processing, the MAXQ3108 dual-core microcontroller accepts three DS8102 output bit streams and decodes and decimates data to produce raw ADC samples. The ADC samples feed into the MAXQ3108's digital-signal processor, which computes power, energy, power factor, and RMS voltage and current parameters necessary for a multifunction meter. Prices for the MAXQ3108 in a 28-pin TSSOP and the DS8102 in a 16-pin TSSOP are $2.43 and $1.17 each/1,000, respectively. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.