Analog Devices Inc.

Category: Data Converters

The AD7938/AD7939 are 12-bit and 10-bit, high speed, lowpower, successive approximation (SAR) analog-to-digitalconverters (ADCs). The parts operate from a single 2.7 V to5.25 V power supply and feature throughput rates up to1.5 MSPS. The parts contain a low noise, wide bandwidth,differential track-and-hold amplifier that can handle inputfrequencies up to 50 MHz.The AD7938/AD7939 feature eight analog input channels witha channel sequencer that allows a preprogrammed selection ofchannels to be converted sequentially. These parts can operatewith either single-ended, fully differential, or pseudodifferential analog inputs.The conversion process and data acquisition are controlledusing standard control inputs that allow easy interfacing withmicroprocessors and DSPs. The input signal is sampled on thefalling edge of CONVST and the conversion is also initiated atthis point.The AD7938/AD7939 have an accurate on-chip 2.5 V referencethat can be used as the reference source for the analog-to-digitalconversion. Alternatively, this pin can be overdriven to providean external reference. These parts use advanced design techniques to achieve verylow power dissipation at high throughput rates. They alsofeature flexible power management options. An on-chip controlregister allows the user to set up different operating conditions,including analog input range and configuration, output coding,power management, and channel sequencing.Product Highlights High throughput with low power consumption. Eight analog inputs with a channel sequencer. Accurate on-chip 2.5 V reference. Single-ended, pseudo differential, or fully differential analog inputs that are software selectable. Single-supply operation with VDRIVE function. The VDRIVE function allows the parallel interface to connect directly to 3 V or 5 V processor systems independent of VDD. No pipeline delay. Accurate control of the sampling instant via a CONVST input and once-off conversion control.

$20.33 - $27.06