Analog Devices Inc.United States

The OP27 precision operational amplifier combines the low offset and drift of the OP07 with both high speed and low noise. Offsets down to 25 μV and maximum drift of 0.6 μV/°C make the OP27 ideal for precision instrumentation applications. Low noise, en = 3.5 nV/√Hz, at 10 Hz, a low 1/f noise corner frequency of 2.7 Hz, and high gain (1.8 million), allow accurate high-gain amplification of low-level signals. A gain bandwidth product of 8 MHz and a 2.8 V/μs slew rate provide excellent dynamic accuracy in high speed, data-acquisition systems. A low input bias current of ±10 nA is achieved by use of a bias current cancellation circuit. Over the military temperature range, this circuit typically holds IB and IOS to ±20 nA and 15 nA, respectively. The output stage has good load driving capability. A guaranteed swing of ±10 V into 600 Ω and low output distortion make the OP27 an excellent choice for professional audio applications. PSRR and CMRR exceed 120 dB. These characteristics, coupled with long-term drift of 0.2 μV/month, allow the circuit designer to achieve performance levels previously attained only by discrete designs. Low cost, high volume production of OP27 is achieved by using an on-chip Zener zap-trimming network. This reliable and stable offset trimming scheme has proven its effectiveness over many years of production history. The OP27 provides excellent performance in low noise, high accuracy amplification of low level signals. Applications include stable integrators, precision summing amplifiers, precision voltage threshold detectors, comparators, and professional audio circuits such as tape heads and microphone preamplifiers.