a FEATURES Wideband AC Performance Gain Bandwidth Product: 400 MHz (Gain ≥ 10) Fast Settling: 100 ns to 0.01% for a 10 V Step Slew Rate: 400 V/s Stable at Gains of 10 or Greater Full Power Bandwidth: 6.4 MHz for 20 V p into a 500 ⍀ Load Precision DC Performance Input Offset Voltage: 0.3 mV max Input Offset Drift: 3 V/؇C typ Input Voltage Noise: 4 nV/√Hz Open-Loop Gain: 130 V/mV into a 1 k⍀ Load Output Current: 50 mA min Supply Current: 12 mA max APPLICATIONS Video and Pulse Amplifiers DAC and ADC Buffers Line Drivers Available in 14-Pin Plastic DIP, Hermetic Cerdip and 20-Pin LCC Packages and in Chip Form MIL-STD-883B Processing Available
Wideband, Fast Settling Op Amp AD840 CONNECTION DIAGRAMS Plastic DIP (N) Package and Cerdip (Q) Package
LCC (E) Package
bandwidth active filters. The extremely rapid settling time of the AD840 makes it the preferred choice for data acquisition applications which require 12-bit accuracy. The AD840 is also appropriate for other applications such as high speed DAC and ADC buffer amplifiers and other wide bandwidth circuitry. APPLICATION HIGHLIGHTS
The AD840 is a member of the Analog Devices’ family of wide bandwidth operational amplifiers. This high speed/high precision family includes, among others, the AD841, which is unitygain stable, and the AD842, which is stable at a gain of two or greater and has 100 mA minimum output current drive. These devices are fabricated using Analog Devices’ junction isolated complementary bipolar (CB) process. This process permits a combination of dc precision and wideband ac performance previously unobtainable in a monolithic op amp. In addition to its 400 MHz gain bandwidth product, the AD840 offers extremely fast settling characteristics, typically settling to within 0.01% of final value in 100 ns for a 10 volt step. The AD840 remains stable over its full operating temperature range at closed-loop gains of 10 or greater. It also offers a low quiescent current of 12 mA maximum, a minimum output current drive capability of 50 mA, a low input voltage noise of 4 nV/√Hz and a low input offset voltage of 0.3 mV maximum (AD840K).
1. The high slew rate and fast settling time of the AD840 make it ideal for DAC and ADC buffers, line drivers and all types of video instrumentation circuitry. 2. The AD840 is truly a precision amplifier. It offers 12-bit accuracy to 0.01% or better and wide bandwidth, performance previously available only in hybrids. 3. The AD840’s thermally balanced layout and the high speed of the CB process allow the AD840 to settle to 0.01% in 100 ns without the long “tails” that occur with other fast op amps. 4. Laser wafer trimming reduces the input offset voltage to 0.3 mV max on the K grade, thus eliminating the need for external offset nulling in many applications. Offset null pins are provided for additional versatility. 5. Full differential inputs provide outstanding performance in all standard high frequency op amp applications where circuit gain will be 10 or greater. 6. The AD840 is an enhanced replacement for the HA2540.
The 400 V/µs slew rate of the AD840, along with its 400 MHz gain bandwidth, ensures excellent performance in video and pulse amplifier applications. This amplifier is ideally suited for use in high frequency signal conditioning circuits and wide REV. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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