The AD7402, AD7403, and AD7405 are high performance, second-order, Σ-Δ modulators that convert 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 modulators operate from a 4.5 to 5.5 V (V_DD1) (AD7402) power supply or from a 5 V (V_DD1) (AD7403/AD7405) power supply. The modulators accept 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 10 MHz (AD7402) or 20 MHz (AD7403/AD7405). The original information can be reconstructed with an appropriate digital filter to achieve 87 dB signal to noise ratio (SNR) at 39 kSPS (AD7402) or 88 dB signal-to-noise ratio (SNR) at 78.1 kSPS (AD7403/AD7405). The serial input/output can use a 3 V to 5.5 V or a 3.3 V supply (V_DD2) (AD7402) or 5 V or a 3 V supply (V_DD2) (AD7403). The LVDS input/output can use a 5 V or a 3.3 V supply (V_DD2) (AD7405).

The serial and LVDS interfaces are digitally isolated. This combined with monolithic transformer technology, means the on-chip isolation provides outstanding performance characteristics; superior to alternatives such as optocoupler devices. The AD7402 and AD7403-8 devices are offered in an 8-lead wide body SOIC package and have an operating temperature range of -40°C to 105°C. The AD7403 and AD7405 devices are offered in a 16-lead, wide-body SOIC package and have an operating temperature range of -40°C to 125°C.