The AD7405 is a high performance, second-order, Σ-Δ modulator that converts an analog input signal into a high speed, single-bit LVDS data stream, with on-chip digital isolation based on Analog Devices, Inc., iCoupler® technology. The AD7405 operates from a 5 V (VDD1) power supply and accepts a differential input signal of ±250 mV (±320 mV 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 20 MHz. The original information can be reconstructed with an appropriate digital filter to achieve 88 dB signal to noise ratio (SNR) at 78.1 kSPS. The LVDS input/output can use a 5 V or a 3.3 V supply (VDD2).
The LVDS interface is digitally isolated. The LVDS interface technology, combined with monolithic transformer technology, means the on-chip isolation provides outstanding performance characteristics, superior to alternatives such as optocoupler devices. The AD7405 device is offered in a 16-lead, wide-body SOIC package and has an operating temperature range of −40°C to +125°C.