12-Bit, 70-MSPS Analog-to-Digital Converter (ADC)

The ADS808 is a high-dynamic range, 12-bit, 70MHz, pipelined Analog-to-Digital Converter (ADC). It includes a high-bandwidth linear track-and-hold that has a low jitter of only 0.25ps rms, leading to excellent SNR performance. The clock input can accept a low-level differential sine wave or square wave signal down to 0.5Vp-p, further improving the SNR performance. It also accepts a single-ended clock signal and has flexible threshold levels.

The ADS808 has a 2Vp-p differential input range (1Vp-p • 2 inputs) for optimum signal-to-noise ratio. The differential operation gives the lowest even-order harmonic components. A lower input voltage of 1.5Vp-p or 1Vp-p can also be selected using the internal references, further optimizing SFDR. Alternatively, a single-ended input range can be used by tying the IN\ input to the common-mode voltage, if desired.

The ADS808 also provides an over-range flag that indicates when the input signal has exceeded the converter’s full-scale range. This flag can also be used to reduce the gain of the front-end signal conditioning circuitry. It also employs digital error-correction techniques to provide excellent differential linearity for demanding imaging applications. The ADS808 is available in a small TQFP-48 PowerPAD™ thermally enhanced package.