SPT7725

SPT7725 8-BIT, 300 MSPS, FLASH A/D CONVERTER TECHNICAL DATA AUGUST 17, 2001 FEATURES Metastable errors reduced to 1 LSB Low input capacitance: 10 pF Wide input bandwidth: 210 MHz 300 MSPS conversion rate Typical power dissipation: 2.2 watts APPLICATIONS Digital oscilloscopes Transient capture Radar, EW, ECM Direct RF down-conversion Medical electronics: ultrasound, CAT instrumentation GENERAL DESCRIPTION The SPT7725 is a monolithic flash A/D converter capable of digitizing a two volt analog input signal into 8-bit digital words at a 300 MSPS (typ) update rate. For most applications, no external sample-and-hold is required for accurate conversion due to the device’s narrow aperture time, wide bandwidth, and low input capacitance. A single standard –5.2 volt power supply is required for operation of the SPT7725, with nominal power dissipation of 2.2 W. A proprietary decoding scheme reduces metastable errors to the 1 LSB level. The SPT7725 is available in 42-lead ceramic sidebrazed DIP, surface-mount 44-lead cerquad, and 46-lead PGA packages (all are pin-compatible with the SPT7710); the cerquad and PGA packages allow access to additional reference ladder taps, an overrange bit, and a data ready output. The SPT7725 is available in the industrial temperature range. BLOCK DIAGRAM VRTS VRTF Analog Input (Force or Sense) AGND DGND VEE LINV MINV Preamp 256 Comparator DRINV MSB D7 DREAD Clock Buffer 255 VR3 152 Overrange 151 D7 MSB 128 VR2 127 D6...