Analog Devices Inc. ADuM7703 16-Bit Isolated Sigma-Delta ADC

Analog Devices Inc. ADuM7703 16-Bit Isolated Sigma-Delta (Σ-Δ) Analog to Digital Converter (ADC) is designed to convert an analog input signal to a high-speed, single-bit data stream. Featuring an integrated Low Dropout (LDO) Regulator, the ADuM7703 ADC provides high isolation between the analog input, a current sensing resistor or shunt, and the digital output. A digital filter then processes the output signal to provide an N-bit word. The ADC Device operates from a 4.5V to 20V power supply range (V_DD1) and accepts a pseudo-differential input signal of ±250mV (±320mV full-scale). The pseudo-differential input is ideally suited to shunt voltage monitoring in high-voltage applications requiring galvanic isolation.

Analog Devices ADuM7703 continuously samples the analog input via a high-performance analog modulator and converts it to a single-bit digital output stream with a data rate of up to 21MHz. The original information can be reconstructed with an appropriate sinc3 digital filter to achieve an 86dB signal-to-noise ratio (SNR) at 78.1kSPS with a 256 decimation rate and a 20MHz master clock. The serial input and output operates from a 5V or a 3.3V supply (V_DD2).

The serial interface is digitally isolated. High-speed complementary metal-oxide semiconductor (CMOS) technology, combined with monolithic transformer technology, results in the on-chip isolation providing outstanding performance characteristics, superior to alternatives such as optocoupler devices.

The Analog Devices Inc. ADuM7703 is offered in an 8-lead, wide-body SOIC package, with an operating temperature range of -40°C to +105°C. This device is also available in a 16-lead, wide-body SOIC with an extended operating temperature range of -40°C to +125°C.

Features

5MHz to 21MHz master clock input frequency
±0.6μV/°C maximum Offset drift vs. temperature
86dB typical SNR
16 bits, no missing codes
Full-scale analog input voltage range
14 bits typical effective number of bits (ENOB)
10mA maximum I_DD1
On-board digital isolator
20V operation on V_DD1
150kV/μs minimum high CMTI, V_DD2 = 3.3V

Safety and regulatory approvals
- UL recognition
  - 5700V_rms for 1 minute per UL 1577
- CSA Component Acceptance Notice 5A (Pending)
- VDE Certificate of Conformity
  - DIN V VDE V 0884-10: V_IORM = 1270V_PEAK
  - DIN V VDE V 0884-11: V_IORM = 1060V_PEAK (Pending)
Package and operating temperature range
- 16-lead SOIC_W; -40°C to +125°C
- 8-lead SOIC_IC with increased creepage; -40°C to +105°C