Data Sheet ACPL-798J Optically Isolated Sigma-Delta Modulator with LVDS Interface Description Features The Broadcom ACPL-798J is a 1-bit, second-order sigma- Up to 25 MHz external clock input range delta (-) modulator that oversamples an analog input signal LVDS clock and data interface. into a highspeed data stream with galvanic isolation based on 1-bit, second-order sigma-delta modulator optical coupling technology. The ACPL-798J operates from a 16 bits resolution no missing codes (12 bits ENOB) 5 V power supply with dynamic range of 82 dB with an 75 dB Typical SNDR appropriate digital filter. The differential inputs of 200 mV (full scale 320 mV) are ideal for direct connection to shunt 3.5 V/C maximum offset drift resistors or other low-level signal sources in applications such 1% maximum gain error as motor phase current measurement. 200 mV linear range with single 5 V supply 40C to +105C operating temperature range The analog input is continuously sampled by means of sigma- delta oversampling using external clock, coupled across the SO-16 package isolation barrier, which allows synchronous operation with any 25 kV/s common-mode transient immunity digital controller. The signal information is contained in the Safety and regulatory approval (pending): modulator data, as a density of ones with data rate up to IEC/EN/DIN EN 60747-5-5: 1414 Vpeak working 25 MHz, and the data are encoded and transmitted across insulation voltage the isolation boundary where they are recovered and UL 1577: 5000 V /1min double protection rating decoded into high-speed data stream of digital ones and rms zeros. The original signal information can be reconstructed CSA: Component Acceptance Notice 5 with a digital filter. The ACPL-798J comes with an LVDS Applications interface on both clock inputs and data outputs for better signal integrity. Motor phase and rail current sensing Power inverter current and voltage sensing Combined with superior optical coupling technology, the modulator delivers high noise margins and excellent immunity Industrial process control against isolation-mode transients. With 0.5 mm minimum Data acquisition systems distance through insulation (DTI), the ACPL-798J provides General-purpose current and voltage sensing reliable double protection and high working insulation voltage, Traditional current transducer replacement 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 an SO-16 package, the CAUTION It is advised that normal static precautions be isolated ADC delivers the reliability, small size, superior taken in handling and assembly of this isolation and over-temperature performance motor drive component to prevent damage and/or designers need to accurately measure current at much lower degradation which can be induced by ESD. price compared to traditional current transducers. Broadcom AV02-4339EN July 19, 2019ACPL-798J Data Sheet Optically Isolated Sigma-Delta Modulator with LVDS Interface Functional Block Diagram V V DD1 DD2 MDAT+ LED V + IN DECODER MODULATOR/ DRIVER MDAT- V ENCODER IN SHIELD MCLKIN+ LED CLOCK DRIVER DETECTOR MCLKIN- V SHIELD REF ACPL-798J GND2 GND1 Pin Configuration and Descriptions ACPL-798J V 1 16 GND2 DD1 V + 2 15 NC IN V 3 14 V IN DD2 GND1 4 13 MCLKIN+ NC 5 12 MCLKIN NC 6 11 MDAT+ V 7 10 MDAT DD1 GND1 8 9 GND2 Table 1: Pin Descriptions Pin No. Symbol Description 1, 7 V Supply voltage for input side relative to GND1. DD1 2V Positive analog input, recommended input range 200 mV. IN+ 3V Negative analog input, recommended input range 200 mV (normally connected to GND1). IN 4,8 GND1 Supply ground for signal input side. 5, 6, 15 NC No connection. Leave floating. 9, 16 GND2 Supply ground for data output side (digital side). 11 MDAT+ Positive LVDS modulator data output. 10 MDAT Negative LVDS modulator data output. 13 MCLKIN+ Positive LVDS modulator clock input 12 MCLKIN Negative LVDS modulator clock input 14 V Supply voltage for output side, referenced to GND2. DD2 Broadcom AV02-4339EN 2 BUF