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 SPITM/ QSPITM and MICROWIRETM 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.
VDDto AGND, DGND................................................. .-0.3V to 6V
AGND to DGND...................................................... -0.3V to 0.3V
CH0(R)CCH7, COM to AGND, DGN.............. -0.3V to (VDD+ 0.3V)
VREF, REFADJ to AGND.............................. -0.3V to (VDD+ 0.3V)
Digital Inputs to DGND............................................. -0.3V to 6V
Digital Outputs to DGND........................... .-0.3V to (VDD+ 0.3V)
Digital Output Sink Current................................................25mA
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 11.11mW/°C above +70°C) ...... 889mW
SSOP (derate 8.00mW/°C above +70°C) ................. 640mW
CERDIP (derate 11.11mW/°C above +70°C)............. 889mW
Operating Temperature Ranges
MAX148_C_P/MAX149_C_P.............................. 0°C to +70°C
MAX148_E_P/MAX149_E_P............................ -40°C to +85°C
MAX148_MJP/MAX149_MJP........................ ...-55°C to +125°C
Storage Temperature Range........................... -60°C to +150°C
Lead Temperature (soldering, 10sec)............................. +300°C
Required Field 
