MAX149

The MAX148/MAX149 10-bit data-acquisition systems combine an 8-channel multiplexer, high-bandwidth track/hold, and serial interface with high conversion speed and low power consumption. They operate from a single +2.7V to +5.25V supply, and sample to 133ksps. Both devices°O analog inputs are software configurable fo unipolar/bipolar and single-ended/differential operation.

The 4-wire serial interface connects directly to SPI^TM/ QSPI^TM and MICROWIRE^TM devices without external logic. A serial-strobe output allows direct connection to TMS320-family digital signal processors. The MAX148/MAX149 use either the internal clock or an external serial-interface clock to perform successive-approximation analog-to-digital conversions. The MAX149 has an internal 2.5V reference, while the MAX148 requires an external reference. Both parts have a reference-buffer amplifier with a ±1.5% voltage adjustment range.

These devices provide a hard-wired SHDN pin and a software-selectable power-down, and can be pro- grammed to automatically shut down at the end of a con-version. Accessing the serial interface automatically  powers up the MAX148/MAX149, and the quick turn-on time allows them to be shut down between all conver- sions. This technique can cut supply current to under 60PAA at reduced sampling rates.

The MAX148/MAX149 are available in a 20-pin DIP and a 20-pin SSOP.

For 4-channel versions of these devices, see the MAX1248/MAX1249 data sheet.