ACPL-7970 Optically Isolated Sigma-Delta Modulator Data Sheet Description Features 10 MHz internal clock The ACPL-7970 is a 1-bit, second-order sigma-delta (-) modulator converts an analog input signal into a high- 1-bit, second-order sigma-delta modulator speed data stream with galvanic isolation based on optical 16 bits resolution no missing codes (12 bits ENOB) coupling technology. The ACPL-7970 operates from a 5 V 78 dB SNR power supply with dynamic range of 78 dB with an appro- 6 mV/C maximum offset drift priate digital filter. The differential inputs of 200 mV (full 1% maximum gain error scale 320 mV) are ideal for direct connection to shunt Internal reference voltage resistors or other low-level signal sources in applications such as motor phase current measurement. 200 mV linear range with single 5 V supply (320 mV full scale) The analog input is continuously sampled by a means of 3 V to 5.5 V wide supply range for digital interface sigma-delta over-sampling using an on-board clock. The -40 C to +105 C operating temperature range signal information is contained in the modulator data, as a density of ones with data rate of 10 MHz, and the data are 25 kV/ms common-mode transient immunity encoded and transmitted across the isolation boundary Safety and regulatory approvals: where they are recovered and decoded into high-speed IEC/EN/DIN EN 60747-5-5: 891 Vpeak working data stream of digital ones and zeros. The original signal insulation voltage information can be reconstructed with a digital filter. The UL 1577: 5000 Vrms/1min isolation voltage serial interface for data and clock has a wide supply range CSA: Component Acceptance Notice 5 of 3 V to 5.5 V. Applications Combined with superior optical coupling technology, Motor phase and rail current sensing the modulator delivers high noise margins and excellent immunity against isolation-mode transients. With 0.5 mm Power inverter current and voltage sensing minimum distance through insulation (DTI), the ACPL-7970 Industrial process control provides reliable reinforced insulation and high working Data acquisition systems insulation voltage, which is suitable for fail-safe designs. General purpose current and voltage sensing This outstanding isolation performance is superior to Traditional current transducer replacements alternatives including devices based on capacitive- or magnetic-coupling with DTI in micro-meter range. Oerff ed Functional Block Diagram in a DIP-8 package, the isolated ADC delivers the reliabil- ity, small size, superior isolation and over-temperature V V DD1 DD2 performance motor drive designers need to accurately measure current at much lower price compared to tradi- - V MCLK IN+ LED MODULATOR/ DECODER tional current transducers. DRIVER V ENCODER IN MDAT The external clock version modulator ACPL-796J (SO-16 SHIELD CLK package) is also available. V REF GND1 GND2 CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by ESD. BUFPin Configuration and Descriptions V 8 V DD1 1 DD2 V 2 7 MCLK IN+ ACPL-7970 V 3 6 MDAT IN 5 GND1 4 GND2 Figure 1. Pin configuration. Table 1. Pin descriptions. Pin No. Symbol Description 1 V Supply voltage for signal input side (analog side), relative to GND1 DD1 2 V + Positive analog input, recommended input range 200 mV IN 3 V Negative analog input, recommended input range 200 mV (normally connected to GND1) IN 4 GND1 Supply ground for signal input side 5 GND2 Supply ground for data/clock output side (digital side) 6 MDAT Modulator data output 7 MCLK Modulator clock output 8 V Supply voltage for data output side, relative to GND2 DD2 Table 2. Ordering Information ACPL-7970 is UL recognized with 5000 Vrms/1 minute rating per UL 1577. Option (RoHS Surface IEC/EN/DIN EN Part number Compliant) Package Mount Gull Wing Tape & Reel 60747-5-5 Quantity ACPL-7970 -000E 300 mil X 50 per tube DIP-8 -300E X X X 50 per tube -500E X X X X 1000 per reel To order, choose a part number from the part number column and combine with the desired option from the option column to form an order entry. Example: ACPL-7970-500E to order product of Surface Mount package in Tape and Reel packaging with IEC/EN/DIN EN 60747-5-5 Safety Approval and RoHS compliance. Option datasheets are available. Contact your Avago sales representative or authorized distributor for information. 2