The LM12L458 is a highly integrated 3.3V Data Acquisition System. It combines 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 LM12L458"s eight-input multiplexer. The LM12L458 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.
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 LM12L458 includes a direct memory access (DMA) interface for high-speed conversion data transfer.
Additional applications information can be found in applications notes AN-906 (JAJA265), AN-947 (SNAA012), and AN-949 (SNAA013).
Three Operating Modes: 12-Bit + Sign, 8-Bit + Sign, and “Watchdog”
Single-Ended or Differential Inputs
Built-In Sample-and-Hold
Instruction RAM and Event Sequencer
8-Channel Multiplexer
32-Word Conversion FIFO
Programmable Acquisition Times and Conversion Rates
Self-Calibration and Diagnostic Mode
8- or 16-Bit Wide Data Bus Microprocessor or DSP Interface
CMOS Compatible I/O
## Key Specifications
(fCLK = 6 MHz)
Resolution: 12-Bit + Sign or 8-Bit + Sign
Single Supply: +3 to +5.5 V
13-bit Conversion Time: 7.3 μs
9-bit Conversion Time: 3.5 μs
13-bit Through-Put Rate: 106 k Samples/s (Min)
Comparison Time (“Watchdog” Mode): 1.8 μs (Max)
ILE: ±1 LSB (Max)
Power Consumption: 15 mW (max)
Stand-By Mode: 5 μW (typ)
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