10-Bit, 20Msps ADC

The MAX1425 10-bit, monolithic analog-to-digital converter (ADC) is capable of a 20Msps sampling rate. This device features an internal track-and-hold (T/H) amplifier for excellent dynamic performance; at the same time, it minimizes the number of external components. Low input capacitance of only 8pF minimizes input drive requirements. A wide input bandwidth (up to 150MHz) makes this device suitable for digital RF/IF downconverter applications employing undersampling techniques.

The MAX1425 employs a differential pipelined architecture with a wideband T/H amplifier to maximize throughput while limiting power consumption to only 172mW. The MAX1425 generates an internal +2.5V reference that supplies three additional reference voltages (+3.25V, +2.25V, and +1.25V). These reference voltages provide a differential input range of +2V to -2V. The analog inputs are biased internally to correct the DC level, eliminating the need for external biasing on AC-coupled applications.

A separate +3V digital logic supply input allows for separation of digital and analog circuitry. The output data is in two's complement format. The MAX1425 is available in the space-saving 28-pin SSOP package. For a pin-compatible version at a lower data rate, refer to the MAX1426 data sheet. For a higher data rate, refer to the MAX1424 data sheet.

Applications

* CCD Pixel Processing * IF and Baseband Digitization * IR Focal Plane Arrays * Medical Ultrasound Imaging * Radar * Set-Top Boxes

* Differential Inputs for High Common-Mode Noise Rejection

* Signal-to-Noise Ratio

* 61dB (at fIN = 2MHz)

* 59.3dB (at fIN = 10MHz)

* Internal +2.5V Reference

* 150MHz Input Bandwidth

* Wide ±2V Input Range

* Low Power Consumption: 172mW

* Separate Digital Supply Input for 3V Logic Compatibility

* Single +5V Supply Operation Possible