ADuM7701: 16-Bit, Isolated Sigma-Delta Modulator

30 Jul 2019

The ADuM7701 is a 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 devices operate from a 5 V (VDD1) power supply and accept a pseudo-differential input signal of ±250 mV (±320 mV full scale). The pseudo-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 21 MHz. The original information can be reconstructed with an appropriate digital filter to achieve 86 dB signal to noise ratio (SNR) at 78. l kSPS with a 20 MHz MCLK for the ADuM7701. The serial input/output operates from a 5 V or a 3.3 V 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. The ADuM7701 device is offered in both 16-lead and 8-lead wide-body SOIC packages and have an operating temperature range of -40°C to +125° C.

Drawings/Package

Key Features and Benefits

- 5 MHz to 21 MHz master clock input frequency
- Offset drift vs. temperature: ±0.6 μV/°C maximum
- SNR: 86 dB typical
- 16 bits, no missing codes
- Full-scale analog input voltage range: ±320 mV
- ENOB: 14 bits typical
- I_DD1: 10 mA maximum
- On-board digital isolator
- Operating temperature range: −40°C to +125°C
- High common-mode transient immunity: 150 kV/μs minimum, VDD2 = 3.3 V
- Wide-body SOICs
- 16-lead SOIC_W
- 8-lead SOIC_IC with increased creepage
- Safety and regulatory approvals (pending)
- UL recognition
- 5700 V rms for 1 minute per UL 1577
- CSA Component Acceptance Notice SA
- VOE Certificate of Conformity
- DIN V VDE V 0884-10
- VlORM = 1270 VPEAK
- DIN V VDE V 0884-11
- VlORM = 1060 VPEAK

General Applications

- Shunt current monitoring
- AC motor controls
- Power and solar inverters
- Wind turbine inverters
- Analog-to-digital and optoisolator replacement

Evaluation Board

YES — The ADuM7701 can be evaluated with the EVAL-ADuM7701.