Differential Amplifiers Drive Broad Range of ADCs

A pair of differential amplifiers, the AD8139 and AD8137, can drive 12-, 16- and 18-bit high-speed a/d converters in applications ranging from battery powered data acquisition systems to high-bandwidth instrumentation, communications, military and industrial systems. With its combination of low noise, low distortion and rail-to-rail output, the AD8139 is aimed at 16- and 18-bit high-speed, high resolution ADCs. Input referred noise of this device is specified at 1.9 nV/vHz and spurious-free dynamic range (SFDR) at 1 MHz and 370 MHz bandwidth is 115 dBc. Rail-to-rail output swing allows the amplifier’s entire dynamic range to be used without headroom constraints and operate on a 5V supply. Slated for the battery-powered market, the AD8137 has rail-to-rail output swing, 110 MHz bandwidth and a slew rate of 450 V/µs. It consumes just 1.8 mA of quiescent current and operates off supply voltages of 3V to 12V. Both devices are packaged in a standard 8-pin SOIC or as an 8-lead LFCSP (lead-frame chip scale package). The operating temperature range is -40°C to +125°C. Pricing for the AD8139 is $3.59 each/1,000 and for the AD8137, $1.09. ANALOG DEVICES INC., Wilmington, MA. (800) 262-5643.