ACPL-C797 Optically Isolated Sigma-Delta Modulator Data Sheet Description Features The ACPL-C797 is a 1-bit, second-order sigma-delta ( - ) Superior optical isolation and insulation modulator converts an analog input signal into a high-speed 10-MHz internal clock data stream with galvanic isolation based on optical coupling 1-bit, second-order sigma-delta modulator technology. The ACPL-C797 operates from a 5-V power supply 16 bits resolution no missing codes (12 bits ENOB) with dynamic range of 80 dB with an appropriate digital filter. 78 dB SNR The differential inputs of 200 mV (full scale 320 mV) are ideal 3.5 V/C maximum offset drift for direct connection to shunt resistors or other low-level signal sources in applications, such as motor phase current 1% gain error measurement. Internal reference voltage 200-mV linear range with single 5-V supply (320 mV full scale) The analog input is continuously sampled by a means of sigma-delta over-sampling using an on-board clock. The signal 3-V to 5.5-V wide supply range for digital interface information is contained in the modulator data, as a density of 40C to +105C operating temperature range ones with data rate of 10 MHz, and the data are encoded and SSO-8 package transmitted across the isolation boundary where they are 25-kV/s common-mode transient immunity recovered and decoded into high-speed data stream of digital Safety and regulatory approval: ones and zeros. The original signal information can be IEC/EN/DIN EN 60747-5-5: 1414 Vpeak working reconstructed with a digital filter. The serial interface for data insulation voltage and clock has a wide supply range of 3V to 5. V. UL 1577: 5000 Vrms/1 min isolation voltage Combined with superior optical-coupling technology, the CSA: Component Acceptance Notice 5 modulator delivers high noise margins and excellent immunity against isolation-mode transients. With 0.5-mm minimum Applications distance through insulation (DTI), the ACPL-C797 provides reliable reinforced insulation and high working insulation Motor phase and rail current sensing voltage, which is suitable for fail-safe designs. This outstanding Power inverter current and voltage sensing isolation performance is superior to alternatives, including Industrial process control devices based on capacitive- or magnetic-coupling with DTI in Data acquisition systems micro-meter range. Offered in a Stretched SO-8 (SSO-8) General purpose current and voltage sensing package, the isolated ADC delivers the reliability, small size, superior isolation, and over-temperature performance that Traditional current transducer replacements motor drive designers need to accurately measure current at much lower price compared to traditional current transducers. CAUTION It is advised that normal static precautions be taken in handling and assembly of this The external clock version modulator ACPL-796J (SO-16 component to prevent damage and/or package) is also available. degradation that may be induced by ESD. The components featured in this data sheet are not to be used in military or aerospace applications or environments. Broadcom - 1 -ACPL-C797 Data Sheet Functional Block Diagram Figure 1 Functional Block Diagram V V DD1 DD2 + 6 - MCLK V IN LED MODULATOR/ DECODER DRIVER V ENCODER IN MDAT SHIELD CLK V REF GND1 GND2 Pin Configurations and Descriptions Figure 2 Pin Configuration V 1 8 V DD1 DD2 + V 7 MCLK IN 2 ACPL-C797 V 3 6 MDAT IN GND1 4 5 GND2 Table 1 Pin Descriptions Pin No. Symbol Description 1 VDD1 Supply voltage for signal input side (analog side), relative to GND1 2 VIN+ Positive analog input, recommended input range 200 mV 3 VIN- Negative analog input, recommended input range 200 mV (normally connected to GND1) 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 VDD2 Supply voltage for data output side, relative to GND2 Broadcom - 2 - BUF