The LM12434 and LM12 L 438 are highly integrated Data Acquisition Systems Operating on 3V to 5V they combine a fully-differential self-calibrating (correcting linearity and zero errors) 13-bit (12-bit a sign) analog-to-digital converter (ADC) and sample-and-hold (S H) with extensive analog and digital functionality Up to 32 consecutive conversions using two's complement format can be stored in an internal 32-word (16-bit wide) FIFO data buffer An internal 8-word instruction RAM can store the conversion sequence for up to eight acquisitions through the LM12 L 438's eight-input multiplexer The LM12434 has a four-channel multiplexer a differential multiplexer output and a differential S H input The LM12434 and LM12 L 438 can also operate with 8-bit a sign resolution and in a supervisory ``watchdog'' mode that compares an input signal against two programmable limits