LM12L438

LM12434 LM12 L 438 12-Bit a Sign Data Acquisition System with Serial I O and Self-Calibration July 1995 LM12434 LM12 L 438 12-Bit a Sign Data Acquisition System with Serial I O and Self-Calibration General Description 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 Acquisition times and conversion rates are programmable through the use of internal clock-driven timers The differential reference voltage inputs can be externally driven for absolute or ratiometric operation All registers RAM and FIFO are directly accessible through the high speed and flexible serial I O interface bus The serial interface bus is user selectable to interface with the following protoco...