The MAX146 has an internal 2.5V reference, while the MAX147 requires an external reference. Both parts have a reference-buffer amplifier with a 1.5% voltageadjustment 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 MAX146/MAX147, and the quick turn-on time allows them to be shut down between all conversions. This technique can cut supply current to under 60A at reduced sampling rates. The MAX146/MAX147 are available in 20-pin DIP and SSOP packages.