The LM12458, and LM12H458 are highly integrated Data Acquisition Systems. Operating on just 5V, they combine a fully-differential self-calibrating (correcting linearity and zero errors) 13-bit (12-bit + sign) analog-to-digital converter (ADC) and sample-and-hold (S/H) with extensive analog functions 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 RAM can store the conversion sequence for up to eight acquisitions through the LM12(H)458"s eight-input multiplexer. The obsolete LM12454 has a four-channel multiplexer, a differential multiplexer output, and a differential S/H input. The LM12(H)458 can also operate with 8-bit + sign resolution and in a supervisory "watchdog" mode that compares an input signal against two programmable limits.
●Programmable acquisition times and conversion rates are possible through the use of internal clock-driven timers. The reference voltage input can be externally generated for absolute or ratiometric operation or can be derived using the internal 2.5V bandgap reference.
●All registers, RAM, and FIFO are directly addressable through the high speed microprocessor interface to either an 8-bit or 16-bit data bus. The LM12(H)458 includes a direct memory access (DMA) interface for high-speed conversion data transfer.
●Additional applications information can be found in applications notes AN-906, AN-947 and AN-949.
●(fCLK = 5 MHz; 8 MHz, H)
