Analog Devices Inc. AD7403 16-Bit Isolated Sigma-Delta Modulators

Analog Devices Inc. AD7403/-8 16-Bit Isolated Sigma-Delta Modulators are high performance, second-order, Σ-Δ modulator that converts an analog input signal into a high speed, single-bit data stream, with on-chip digital isolation based on Analog Devices, Inc., iCoupler® technology. The AD7403/-8 operates from a 5V (VDD1) power supply and accepts a differential input signal of ±250mV (±320mV full-scale). The differential input is ideally suited to shunt voltage monitoring in high voltage applications where galvanic isolation is required. The analog input is continuously sampled by a high performance analog modulator, and converted to a ones density digital output stream with a data rate of up to 20MHz. 

The original information can be reconstructed with an appropriate digital filter to achieve 88dB signal to noise ratio (SNR) at 78.1kSPS. The serial input/output can use a 5V or a 3V supply (VDD2). The serial interface is digitally isolated. High speed complementary metal oxide semiconductor (CMOS) technology, combined with monolithic transformer technology, means the on-chip isolation provides outstanding performance characteristics, superior to alternatives such as optocoupler devices.


  • 5MHz to 20MHz external clock input rate
  • 16 bits, no missing codes
  • Signal-to-noise ratio (SNR): 88dB typical
  • Effective number of bits (ENOB): 14.2 bits typical
  • Offset drift vs. temperature:
    • AD7403: 1.6μV/°C typical
    • AD7403-8: 2μV/°C typical
  • On-board digital isolator
  • On-board reference
  • Full-scale analog input range: ±320mV
  • Operating range 
  • AD7403: -40°C to + 125°C
  • AD7403/-8: -40°C to + 105°C
  • High common-mode transient immunity: >25kV/μs
  • 16-lead, wide-body SOIC, with increased creepage package
  • Slew rate limited output for low electromagnetic interference (EMI)
  • Safety and regulatory approvals (pending)
    • UL recognition
      • 5000Vrms for 1 minute per UL 1577
    • CSA Component Acceptance Notice 5A
    • VDE Certificate of Conformity
      • DIN V VDE V 0884-10 (VDE V 0884-10): 2006-12 VIORM = 1250VPEAK


  • Shunt current monitoring
  • AC motor controls
  • Power and solar inverters
  • Wind turbine inverters
  • Data acquisition systems
  • Analog-to-digital and opto-isolator replacements
Publicado: 2014-07-10 | Actualizado: 2022-03-11