Out in Front: August 15, 1996

The trend toward packing more linear functions into ever-smaller packages continues with Maxim's MAX1247. The device multiplexes four single-ended inputs or two differential inputs, passes them through an internal track/hold circuit, and digitizes them with 12-bit resolution at speeds as high as 133k samples/sec. You can configure inputs for unipolar or bipolar spans via software. The 16-lead device, which comes in a QSOP package measuring 1.73 mm high, occupies just 28% of the area of a standard 2.65-mm-high, small-outline package.

The MAX1247 uses a 2.7 to 5.25V supply and consumes 0.9 mA at the maximum sampling rate with a 3V supply. Current consumption is 10 µA at 1k samples/sec and 1 µA in power-down mode. The device's four-wire serial interface is compatible with the Microwire, serial-peripheral-interface (SPI), and QSPI standards and the TMS320 DSP. You can program the IC to shut down at the end of each conversion, thus minimizing total power consumption, and any access of the serial interface then reactivates the IC. Prices start at $5.80 (1000) for the 12-bit A/D converter; a 10-bit version that is functionally identical costs $3.95. Both versions are also available in 16-pin DIP packaging.

—by Bill Schweber

Maxim Integrated Products, Sunnyvale, CA. (408) 737-7600, ext 6277, http://www.maxim-ic.com.