The MAX1204 is a 10-bit data-acquisition system specifically designed for use in applications with mixed +5V (analog) and +3V (digital) supply voltages. It operates with a single +5V analog supply or dual 5V analog supplies, and combines an 8-channel multiplexer, internal track/hold, and serial interface with high conversion speed and low power consumption. A 4-wire serial interface connects directly to SPITM/MicrowireTM devices without external logic, and a serial strobe output allows direct connection to TMS320-family digital signal processors. The MAX1204 uses either the internal clock or an external serialinterface clock to perform successive-approximation analog-to-digital conversions. The serial interface operates at up to 2MHz. The MAX1204 features an internal 4.096V reference and a reference-buffer amplifier that simplifies gain trim. It also has a VL pin that supplies power to the digital outputs. Output logic levels (3V, 3.3V, or 5V) are determined by the value of the voltage applied to this pin. A hard-wired SHDN pin and two software-selectable power-down modes are provided. Accessing the serial interface automatically powers up the device. A quick turn-on time allows the MAX1204 to be shut down between conversions, enabling the user to optimize supply currents. By customizing power-down between conversions, supply current can drop below 10A at reduced sampling rates.