The full-scale analog input range is determined by the internal reference of +2.048V (MAX1108) or +4.096V (MAX1109), or by an externally applied reference ranging from 1V to VDD. The MAX1108/MAX1109 also feature a software power-down mode that reduces power consumption to 0.5A when the device is not in use. The 4-wire serial interface directly connects to SPITM, QSPITM, and MICROWIRETM devices without external logic. Conversions up to 50ksps are performed using either the internal clock or an external serial-interface clock.