Differential SAR ADCs run from a single VDD power supply

11-02-2020 | Analog Devices | Semiconductors

Analog Devices AD4021/AD4022 Differential SAR ADCs are high speed, high accuracy, low power, 20-bit, Easy Drive, precision SAR ADCs that run from a single VDD power supply. The device's reference voltage is applied externally and is able to be set independent of the supply voltage. Additionally, the devices' power scales linearly with throughput.


The ADCs feature Easy Drive, which lessens both signal chain complexity and power consumption while facilitating higher channel density. The decreased input current, especially in high-Z mode, coupled with a long signal acquisition phase, removes the requirement for a dedicated ADC driver. The Easy Drive feature allows the range of companion circuitry to widen that is able of driving the AD4021/AD4022.


The ADCs provide input span compression that removes the necessity to offer a negative supply to the ADC driver amplifier while preserving access to the full ADC code range. The input overvoltage clamp removes the requirement for external protection diodes by protecting the ADC inputs against overvoltage events and minimising disturbances on the reference pin. The fast device throughput up to 1.8 MSPS enables users to precisely capture high-frequency signals and to implement oversampling techniques to lighten the challenges associated with antialias filter designs. The decreased SPI clock rate demands, reduce digital input/output power consumption, widens digital host options, and simplifies the task of sending data across digital isolation. The SPI-compatible serial user interface is compatible with 1.8V, 2.5V, 3V, and 5V logic by employing the separate VIO logic supply.


The differential SAR ADCs are offered in 10-lead packages of 3mm x 3mm LFCSP and 3mm x 4.90mm MSOP. They are pin-compatible with the AD4003/AD4007/AD4011 16/18-Bit SAR ADCs.


Typical applications automatic test equipment, machine automation, medical equipment, battery-powered equipment, precision data acquisition systems, and instrumentation and control systems.

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