Automotive R²Coupler™ Optically Isolated Sigma-Delta Modulator

Currently Viewing:

The Broadcom ACPL-C797T is an optically isolated 1-bit, 2nd order Sigma-Delta (Σ-Δ) modulator device that is automotive qualified per AEC-Q100 Grade 1. The device converts an analog input signal into a high speed data stream with galvanic isolation based on optical coupling technology. The device operates from a 5V power supply, and has a dynamic range of 79 dB. The differential input range of ±200 mV (full scale ±320 mV) is ideal for direct connection to shunt resistors or other low level signal sources in applications such as motor phase current measurement.

The ACPL-C797T isolated modulator converts a low bandwidth analog input into a high speed 1-bit data stream by means of Sigma-Delta (Σ-Δ) over-sampling modulator.  The modulator data and on-chip sampling clock are encoded and transmitted across the isolation barrier where they are recovered and decoded into separate high speed clock and data channels. Combined with superior optical coupling technology, the modulator delivers high noise margin and excellent immunity against isolation-mode transients.

Offered in a compact, surface mount stretched SO-8 package, the device delivers the reliability, small size, superior isolation and stable performance across automotive temperature range that motor drive designers need to accurately measure current. Broadcom R2Coupler isolation products provide the reinforced insulation and reliability needed for critical automotive and high temperature industrial applications.


  • Qualified to AEC-Q100 Grade 1 Test Guidelines
  • Automotive Operating Temperature -40 to +125°C
  • 1-bit, 2nd Order Σ-Δ Modulator
  • 10MHz Internal Clock
  • 16-bit Resolution with No Missing Code (12-bit ENOB)
  • Signal-to-Noise Ratio (SNR): 79 dB typical
  • Gain Error: ±1%
  • ±200mV Linear Range with Single 5V Supply (±320mV full scale)
  • Wide Supply Range for Digital Interface: 3 to 5.5 V
  • High Common-Mode Rejection: 25 kV/μs
  • Compact, Surface-Mount Stretched SO-8 Package 
  • Worldwide Safety Approvals: 
    • UL 1577 (5000 VRMS/1 min.) and CSA
    • IEC/EN/DIN EN 60747-5-5: 1414VPEAK working voltage 


  • Automotive Motor Phase and Rail Current Sensing
  • Automotive Motor Inverter DC Bus Voltage Sensing
  • Automotive DC/DC Converter Voltage/Current Sensing
  • Automotive AC/DC (Charger) Voltage/Current Sensing
  • Automotive Battery Pack Voltage/Current Sensing
  • General Purpose Voltage/Current Sensing and Monitoring

Lifecycle Status


Substance Compliance

  • RoHS6
    Fully Compliant
Specification Value
Lifecycle Active
Distrib. Inventory Yes
RoHS6 Compliant Y
Product Type Automotive Optocoupler
Package Stretched SO8
Gain Error at 25 Deg C (%) Max ±1
VDD2 (V) 3 - 5.5
CMR (min.) (V/µs) 25000.0
Vcm (V) 1000.0
UL Insulation Rating Viso (VRMS) 5000.0
IEC Maximum Working Insulation Voltage Viorm (VPEAK) 1414.0
Data Sheet1 i
Options Data Sheet3 i
Reliability Data Sheet6 i
Photocard1 i


Plastic Automotive Miniature Isolation Amplifier


Automotive High Precision DC Voltage Isolation Sensor


Automotive High Precision DC Voltage Isolation Sensor