Описание
The MAX125/MAX126 are high-speed, multichannel, 14-bit data-acquisition systems (DAS) with simultaneous track/holds (T/Hs). These devices contain a 14-bit, 3µs, successive-approximation analog-to-digital converter (ADC), a +2.5V reference, a buffered reference input, and a bank of four simultaneous-sampling T/H amplifiers that preserve the relative phase information of the sampled inputs. The MAX125/MAX126 have two multiplexed inputs for each T/H, allowing a total of eight inputs. In addition, the converter is overvoltage tolerant to ±17V; a fault condition on any channel will not harm the IC. Available input ranges are ±5V (MAX125) and ±2.5V (MAX126). An on-board sequencer converts one to four channels per active-low CONVST pulse. In the default mode, one T/H output (CH1A) is converted. An interrupt signal (active-low INT) is provided after the last conversion is complete. Convert two, three, or four channels by reprogramming the MAX125/MAX126 through the bidirectional parallel interface. Once programmed, the MAX125/MAX126 continue to convert the specified number of channels per active-low CONVST pulse until they are reprogrammed. The channels are converted sequentially, beginning with CH1. The INT signal always follows the end of the last conversion in a conversion sequence. The ADC converts each assigned channel in 3µs and stores the result in an internal 14×4 RAM. Upon completion of the conversions, data can be accessed by applying successive pulses to the active-low RD pin. Four successive reads access four data words sequentially. The parallel interface"s data-access and bus-release timing specifications are compatible with most popular digital signal processors and 16-bit/32-bit microprocessors, so the MAX125/MAX126 conversion results can be accessed without resorting to wait states.
- Four Simultaneous-Sampling T/H Amplifiers with Two Multiplexed Inputs (eight single-ended inputs total)
- 3µs Conversion Time per Channel
- Throughput:
- 250ksps (1 channel)
- 142ksps (2 channels)
- 100ksps (3 channels)
- 76ksps (4 channels)
- ±5V (MAX125)
- ±2.5V (MAX126)
