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. The output signal is then processed by a digital filter 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 where galvanic isolation is required.

The 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
Offset Drift vs. Temperature: ±0.6μV/°C Maximum
SNR: 86dB Typical
16 Bits, No Missing Codes
Full-scale Analog Input Voltage Range: ±320mV
Effective Number of Bits (ENOB): 14 Bits Typical
I_DD1: 10mA Maximum
On-board Digital Isolator
20V Operation on V_DD1
High CMTI: 150kV/μs Minimum, 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