AD7440

The AD7440/AD7450A¹ are 10-bit and 12-bit high speed, low power, successive approximation (SAR) analog-to-digital converters with a fully differential analog input. These parts operate from a single 3 V or 5 V power supply and use advanced design techniques to achieve very low power dissipation at throughput rates up to 1 MSPS. The SAR architecture of these parts ensures that there are no pipeline delays.

The parts contain a low noise, wide bandwidth, differential track-and-hold amplifier (T/H) that can handle input  requencies up to 3.5 MHz. The reference voltage is applied externally to the V_REF pin and can be varied from 100 mV to 3.5 V depending on the power supply and what suits the application. The value of the reference voltage  etermines the common-mode voltage range of the part. With this truly differential input structure and variable  eference input, the user can select a variety of input ranges and bias points.

The conversion process and data acquisition are controlled using CS and the serial clock, allowing the device to interface with microprocessors or DSPs. The input signals are sampled on the falling edge of CS; the conversion is also initiated at this point. The SAR architecture of these parts ensures that there are no pipeline delays. The AD7440 and the AD7450A use ad-vanced design techniques to achieve very low power dissipation at high throughput rates.