The 4-wire serial interface connects directly to SPITM, QSPITM, and MicrowireTM devices, without using external logic. A serial strobe output allows direct connection to TMS320 family digital signal processors. The MAX192 uses either the internal clock or an external serialinterface clock to perform successive approximation A/D conversions. The serial interface can operate beyond 4MHz when the internal clock is used. The MAX192 has an internal 4.096V reference with a drift of 30ppm typical. A reference-buffer amplifier simplifies gain trim and two sub-LSBs reduce quantization errors. The MAX192 provides a hardwired SHDN pin and two software-selectable power-down modes. Accessing the serial interface automatically powers up the device, and the quick turn-on time allows the MAX192 to be shut down between conversions. By powering down between conversions, supply current can be cut to under 10A at reduced sampling rates. The MAX192 is available in 20-pin DIP and SO packages, and in a shrink-small-outline package (SSOP) that occupies 30% less area than an 8-pin DIP. The data format provides hardware and software compatibility with the MAX186/MAX188. For anti-aliasing filters, consult the data sheets for the MAX291MAX297.