MAXIM MAX1249BEPE

The MAX1248/MAX1249 10-bit data-acquisition systems combine a 4-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 their analog inputs are software configurable for unipolar/bipolar and single-ended/differential operation. The 4-wire serial interface connects directly to SPITM/ QSPITM and MICROWIRETM devices without external logic. A serial strobe output allows direct connection to TMS320-family digital signal processors. The MAX1248/MAX1249 use either the internal clock or an external serial-interface clock to perform successive-approximation analog-to-digital conversions. The MAX1248 has an internal 2.5V reference, while the MAX1249 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 programmed to automatically shut down at the end of a conversion. Accessing the serial interface automatically powers up the MAX1248/MAX1249, and the quick turn-on time allows them to be shut down between all conversions. This technique can cut supply current to under 60μA at reduced sampling rates. The MAX1248/MAX1249 are available in a 16-pin DIP and a very small QSOP that occupies the same board area as an 8-pin SO.

• 4-Channel Single-Ended or 2-Channel Differential Inputs
• Single +2.7V to +5.25V Operation
• Internal 2.5V Reference (MAX1248)
• Low Power: 1.2mA (133ksps, +3V supply), 54μA (1ksps, +3V supply), μA (power-down mode)
• SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire Serial Interface
• Software-Configurable Unipolar or Bipolar Inputs
• 16-Pin QSOP Package (same area as 8-pin SO)

• Portable Data Logging
• Data Acquisition
• Medical Instruments
• Battery-Powered Instruments
• Pen Digitizers
• System Supervision