16-bit sigma-delta modulator includes high-voltage isolation
The AD7402 operates from a 5V (VDD1) power supply and accepts a differential input signal of ±250 mV (±320 mV full scale). The differential input is suited to shunt voltage monitoring in high voltage applications where galvanic isolation is required. The input is continuously sampled by a high performance analogue modulator, and converted to a digital output stream with a data rate of 10 MHz. The original information can be reconstructed with an appropriate digital filter to achieve 87 dB signal to noise ratio (SNR) at 39 ksamples/sec. The serial input/output can use a 5V or a 3.3V supply (VDD2).
The serial interface is digitally isolated. High speed CMOS technology, combined with monolithic transformer technology, means the on-chip isolation provides outstanding performance characteristics, superior to alternatives such as optocoupler devices. The AD7402 comes in an 8-lead wide body SOIC package and has an operating temperature range of −40°C to +105°C; it is priced at $3.05 (1000).
Analog Devices; www.analog.com/en/products/analog-to-digital-converters/precision-adc-10msps/isolated-ad-converters/ad7402.html
next page; safety approvals/applications/ feature list
Safety and regulatory approvals
UL recognition
5000 V rms 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 = 1250 VPEAK
Applications
Shunt current monitoring
AC motor controls
Power and solar inverters
Wind turbine inverters
Data acquisition systems
Analogue-to-digital and opto-isolator replacements
Features and Benefits
10 MHz internal clock rate
16 bits, no missing codes
Signal-to-noise ratio (SNR): 87 dB typical
Effective number of bits (ENOB): 13.5 bits typical
Typical offset drift vs. temperature: 1.7 µV/°C
On-board digital isolator
On-board reference
Full-scale analogue input range: ±320 mV
−40°C to +105°C operating range
High common-mode transient immunity: >25 kV/µsec
8-lead, wide-body SOIC, with increased creepage package
Slew rate limited output for low electromagnetic interference (EMI)
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