AD515A数据手册ADI中文资料规格书

描述 Description

The AD515A is a monolithic FET-input operational amplifierwith a guaranteed maximum input bias current of 75 fA(AD515AL). The AD515A is a monolithic successor to theindustry standard AD515 electrometer, and will replace theAD515 in most applications. The AD515A also delivers laser-trimmedoffset voltage, low drift, low noise and low power, acombination of features not previously available in ultralow biascurrent circuits. All devices are internally compensated, protectedagainst latch-up and are short circuit protected.The AD515A's combination of low input bias current, lowoffset voltage and low drift optimizes it for a wide variety ofelectrometer and very high impedance buffer applicationsincluding photocurrent detection, vacuum ion-gage measurement,long-term precision integration and low drift sample/holdapplications. This amplifier is also an excellent choice for all formsof biomedical instrumentation such as pH/pIon sensitive electrodes,very low current oxygen sensors, and high impedancebiological microprobes. In addition, the low cost and pincompatibility of the AD515A with standard FET op amps willallow designers to upgrade the performance of present systemsat little or no additional cost. The 10 15 W common-mode inputimpedance ensures that the input bias current is essentiallyindependent of common-mode voltage. As with previous electrometer amplifier designs from AnalogDevices, the case is brought out to its own connection (Pin 8)so it can be independently connected to a point at the samepotential as the input, thus minimizing stray leakage to the case.This feature will also shield the input circuitry from externalnoise and supply transients. The AD515A is available in three versions of bias current andoffset voltage, the \"J\", \"K\" and \"L\"; all are specified for ratedperformance from 0°C to +70°C and supplied in a hermeticallysealed TO-99 package.