AD7450:  Differential Input, 1 MSPS, 12-BIT SAR ADC

The AD7450 is a 12-bit, high speed, low power, successive-approximation (SAR) analog-to-digital converter featuring a fully differential analog input. It operates from a single 3 V or 5 V power supply and features throughput rates up to 833 kSPS or 1 MSPS respectively.

This part contains a low-noise, wide bandwidth, differential track and hold amplifier (T/H) which can handle input frequencies in excess of 1 MHz with the –3 dB point being 20 MHz typically. The reference voltage for the AD7450 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 determines the common mode voltage range of the part. With this truly differential input structure and variable reference 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 and the conversion is also initiated at this point. The SAR architecture of this part ensures that there are no pipeline delays.

The AD7450 uses advanced design techniques to achieve very low power dissipation at high throughput rates.