Isolated amp, modulator enable high-precision current measurement in motor control

Isolated amp, modulator enable high-precision current measurement in motor control

The AMC1200 isolated amplifier and AMC1204 delta-sigma modulator are claimed by the company to improve system performance while reducing power consumption. The parts allow designers to increase accuracy, temperature stability, and immunity to magnetic fields in equipment such as ac drives, solar inverters, and uninterruptible power supplies.

The AMC1200 is a 4-kV peak isolated amplifier providing 80% better linearity (maximum nonlinearity of 0.07%) and gain drift (56 ppm/°C) compared to competitive devices while reducing power consumption by 50% (high-side supply current is less than 8 mA at 5 V). This part is specified over –40° to 105°C, which is 20° higher than competitive offerings.

The AMC1204 is a 20-MHz, externally-clocked, isolated delta-sigma modulator that provides 40% better linearity (nonlinearity of ±8 LSB) than the competition, and a digital output that allows designers to define digital filter characteristics based on system requirements. This part includes an external clock interface to enable simultaneous measurment of multiple channels.

Housed is SOIC packages, both devices provide high electromagnetic immunity and a robust isolation barrier certified by UL1577 and IEC 60747-5-2. The AMC1204 is also CSA-certified. (Ea/1,000: AMC1200, $2.20; AMC1204, $3.45 — available now.)

By Christina Nickolas

Texas Instruments , Dallas , TX
Information 800-477-8924
www.ti.com