GENERAL DESCRIPTION

The AD7476/AD7477/AD7478 are, respectively, 12-bit, 10-bit, and 8-bit, high speed, low power, successive-approximation ADCs. The parts operate from a single 2.35 V to 5.25 V power supply and feature throughput rates up to 1 MSPS. The parts contain a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 6 MHz.

The conversion process and data 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 the conversion is also initiated at this point. There are no pipeline delays associated with the part.

The AD7476/AD7477/AD7478 use advanced design techniques to achieve very low power dissipation at high throughput rates.

The reference for the part is taken internally from VDD. This allows the widest dynamic input range to the ADC. Thus the analog input range for the part is 0 V to VDD. The conversion rate is determined by the SCLK.

FEATURES

Fast Throughput Rate: 1 MSPS

Specified for VDD of 2.35 V to 5.25 V

Low Power:

3.6 mW Typ at 1 MSPS with 3 V Supplies

15 mW Typ at 1 MSPS with 5 V Supplies

Wide Input Bandwidth:

70 dB SNR at 100 kHz Input Frequency

Flexible Power/Serial Clock Speed Management

No Pipeline Delays

High Speed Serial Interface

SPI?/QSPI?/MICROWIRE?/DSP Compatible

Standby Mode: 1 μA Max

6-Lead SOT-23 Package

APPLICATIONS

Battery-Powered Systems

Personal Digital Assistants

Medical Instruments

Mobile Communications

Instrumentation and Control Systems

Data Acquisition Systems

High Speed Modems

Optical Sensors