Description

The AD7476A / AD7477A / AD7478A are 12-bit, 10-bit, and 8-bithigh speed, low power, successive-approximation analog-to-digitalconverters (ADCs), respectively. The parts operate froma single 2.35 V to 5.25 V power supply and feature throughputrates up to 1 MSPS. The parts contain a low noise, widebandwidth track-and-hold amplifier that can handle inputfrequencies in excess of 13 MHz. The conversion process anddata acquisition are controlled using CS and the serial clock,allowing the devices to interface with microprocessors or DSPs.The input signal is sampled on the falling edge of CS, and theconversion is also initiated at this point. There are no pipelinedelays associated with the parts. The AD7476A / AD7477A /AD7478A use advanced design techniques to achieve low powerdissipation at high throughput rates. The reference for the partis taken internally from VDD to allow the widest dynamic inputrange to the ADC. Thus, the analog input range for the part is0 V to VDD. The conversion rate is determined by the SCLK.PRODUCT HIGHLIGHTS First 12-/10-/8-bit ADCs in a SC70 package. High throughput with low power consumption. Flexible power/serial clock speed management. The conversion rate is determined by the serial clock, allowing the conversion time to be reduced through the serial clock speed increase. This allows the average power consumption to be reduced when a power-down mode is used while not converting. The parts also feature a power-down mode to maximize power efficiency at lower throughput rates. Current consumption is 1 µA maximum and 50 nA typically when in power-down mode. Reference derived from the power supply. No pipeline delay. The parts feature a standard successive approximation ADC with accurate control of the sampling instant via a CS input and once-off conversion control.APPLICATIONS Battery-powered systems Personal digital assistants Medical instruments Mobile communications Instrumentation and control systems Data acquisition systems High speed modems Optical sensors