Chipset eliminates cost in polyphase energy meters

Chipset eliminates cost in polyphase energy meters

The DS8102 modulator and encoder and the MAXQ3108 microcontroller form a chipset that targets the isolation and data-coupling needs for polyphase energy meters. The chipset replaces three high-cost current transformers with three shunts to save both cost and space.

A three-phase meter uses three modulators and one microcontroller. The modulator converts the voltage and current inputs into a high-frequency digital bit stream and is coupled to the microcontroller through a capacitor. The microcontroller is dc-isolated from the three DS8102 modulators, but ac-coupled to them to accept the digital data bit streams from each. With each modulator isolated from the other phases and from the microcontroller, each phase can use a shunt resistor for its current sensing, which removes the current transformer from the BOM costs.

The DS8102 contains two high-precision second-order delta-sigma modulators with programmable gains up to 32x. The data processing is carried out in the microcontroller, which accepts three modulator output bit streams. The microcontroller’s DSP is programmable, making the chipset suitable for industrial data-acquisition applications where isolation between the physical signals and the data-acquisition instrument is required. (Ea/1,000: MAXQ3108,$2.43; DS8102, $1.17 — available now.)

Maxim Integrated Products , Sunnyvale , CA
Sales Office 888-629-4642

http://www.maxim-ic.com