Electronic Design

Low-Power 12-Bit ADC Fits I<sup>2</sup>C Interface In SOT-23 Package

The 12-bit MCP3221 analog-to-digital converter (ADC) incorporates an I2C interface in an SOT-23 package. The 400-kHz clock rate of the two-wire serial, I2C interface enables sampling rates up to 22.3 ksamples/s for signals of higher bandwidth. The MCP3221 operates from a single 2.7- to 5.5-V supply. The ADC employs a conventional successive approximation register (SAR) architecture, which uses an internal sample-and-hold capacitor to store the analog input while the conversion is taking place. At the end of the acquisition time, the converter's input switch opens, and the device uses the collected charge on the internal sample-and-hold capacitor to produce a serial 12-bit digital output. The acquisition time and conversion are self-timed using an internal clock. The device's low standby and conversion current suit it for battery-powered applications where low power consumption is required. In 1000-unit quantities, the MCP3221 costs $1.18 each.

Microchip Technology Inc.
www.microchip.com; (480) 792-7668

TAGS: Microchip
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