16-bit SAR ADC with true bipolar differential input
The AD7665ASTZRL is a 16-bit successive-approximation (SAR) ADC from Analog Devices' PulSAR® series, sampling at 570k samples per second. It accepts a true bipolar differential input signal, meaning it can digitize both positive and negative voltages referenced to a common-mode point without external level-shifting circuitry. The single-ended-to-differential conversion is handled internally by the S/H-ADC front end (1:1 ratio), simplifying the analog interface for precision measurement chains. The digital side offers three interface options — SPI, parallel, and DSP — making it adaptable to a wide range of host controllers and FPGA-based systems. A single external reference sets the full-scale range, giving the designer control over the LSB weight and input span.