ACPL-7970 Datasheet | Avago Technologies

ACPL-7970 Optically Isolated Sigma-Delta Modulator Data Sheet Description The ACPL-7970 is a 1-bit, second-order sigma-delta (∑-∆) modulator converts an analog input signal into a highspeed data stream with galvanic isolation based on optical coupling technology. The ACPL-7970 operates from a 5 V power supply with dynamic range of 78 d B with an appropriate digital filter. The differential inputs of ±200 m V (full scale ±320 m V) are ideal for direct connection to shunt resistors or other low-level signal sources in applications such as motor phase current measurement. The analog input is continuously sampled by a means of sigma-delta over-sampling using an on-board clock. The signal information is contained in the modulator data, as a density of ones with data rate of 10 MHz, and the data are encoded and transmitted across the isolation boundary where they are recovered and decoded into high-speed data stream of digital ones and zeros. The original signal information can be reconstructed with a digital filter. The serial interface for data and clock has a wide supply range of 3 V to 5.5 V. bined with superior optical coupling technology, the modulator delivers high noise margins and excellent immunity against isolation-mode transients. With 0.5 mm minimum distance through insulation (DTI), the ACPL‑7970 provides reliable reinforced insulation and high working insulation voltage, which is suitable for fail-safe designs. This outstanding isolation performance is superior to alternatives including devices based on capacitive- or magnetic-coupling with DTI in micro-meter range. Offered in a DIP-8 package, the isolated ADC delivers the reliability, small size, superior isolation and over-temperature performance motor drive designers need to accurately measure current at much lower price pared to traditional current transducers. The external clock version modulator ACPL-796J (SO-16 package) is also available. Features - 10 MHz internal clock - 1-bit, second-order...