AD642

a FEATURES Matched Offset Voltage Matched Offset Voltage Over Temperature Matched Bias Current Crosstalk: –124 dB @ 1 kHz Low Bias Current: 35 pA max Warmed Up Low Offset Voltage: 500 ␮V max Low Input Voltage Noise: 2 ␮ V p-p High Open Loop Gain Low Quiescent Current: 2.8 mA max Low Total Harmonic Distortion Standard Dual Amplifier Pin Out Available in Hermetic Metal Can Package and Chip Form MIL-STD-883B Processing Available Single Version Available: AD542 Precision, Low Cost Dual BiFET Op Amp AD642 PIN CONFIGURATION PRODUCT DESCRIPTION The AD642 is a pair of matched high speed monolithic BiFET operational amplifier fabricated with the most advanced bipolar, JFET and laser trimming technologies. The AD642 offers matched bias currents that are significantly lower than currently available monolithic dual FET input operational amplifiers: 35 pA max matched to 25 pA for the AD642K and L; 75 pA max, matched to 35 pA for the AD642J and S. In addition, the offset voltage is laser trimmed to less than 0.5 mV and matched to 0.25 mV for the AD642L, 1.0 mV and matched to 0.5 mV for the AD642K, utilizing Analog’s laser-wafer trimming (LWT) process. The tight matching and temperature tracking between the operational amplifiers is achieved by ion-implanted JFETs and laser-wafer trimming. Ion-implantation permits the fabrication of precision, matched JFETs on a monolithic bipolar chip. The optimizes the process to product matched bias currents which have lower initial bias currents than...