ADS1625

The ADS1625 and ADS1626 are high-speed, high-precision, delta-sigma analog-to-digital converters (ADCs) with 18-bit resolution. The data rate is 1.25 mega samples per second (MSPS), the bandwidth (-3dB) is 615kHz, and passband ripple is less than ±0.0025dB (to 550kHz). Both devices offer the same outstanding performance at these speeds with a signal-to-noise ratio up to 93dB, total harmonic distortion down to -101dB, and a spurious-free dynamic range up to 103dB. The ADS1626 includes an adjustable first-in, first-out buffer (FIFO) for the output data.

The input signal is measured against a voltage reference that can be generated on-chip or supplied externally. The digital output data is provided over a simple parallel interface that easily connects to digital signal processors (DSPs). An out-of-range monitor reports when the input range has been exceeded. The ADS1625/6 operate from a +5V analog supply (AVDD) and +3V digital supply (DVDD). The digital I/O supply (IOVDD) operates from +2.7 to +5.25V, enabling the digital interface to support a range of logic families. The analog power dissipation is set by an external resistor and can be reduced when operating at slower speeds. A power-down mode, activated by a digital I/O pin, shuts down all circuitry. The ADS1625/6 are offered in a TQFP-64 package using TI PowerPAD™ technology.

The ADS1625 and ADS1626, along with their 16-bit, 5MSPS counterparts, the ADS1605 and ADS1606, are well-suited for the demanding measurement requirements of scientific instrumentation, automated test equipment, data acquisition, and medical imaging.