The AD74021 is a high-performance, second-order, delta-Sigma modulator that converts analog input signals into high-speed, single-bit data streams with digital-on-chip isolation based on analog Devices, Inc., iCoupler Technology. Available in an 8-pin wide-body SOIC package, the operating temperature range is −40°C to +105°C.
Typical Application Circuit
The AD7402 is powered from a 4.5V to 5.5V (VDD1) power supply and accepts differential input signals of ±250 mV(full-scale ±320 mV). Differential inputs are ideal for shunt voltage monitoring in high-voltage applications where electrical isolation is required. The analog input is continuously sampled by a high performance analog modulator and converted into a digital output stream with a density of 10mhz.
Functional block diagram
The original information can be reconstructed with an appropriate digital filter, reaching a signal-to-noise ratio of 87 dB at 39 kSPS. The serial input/output can use 3v ~ 5.5V or 3.3V power supply (VDD2). The serial port is digitally isolated. The combination of high-speed complementary metal oxide semiconductor (CMOS) technology with monolithic transformer technology means that on-chip isolation offers excellent performance characteristics over alternatives such as optocoupler devices.
Data time graph
