The AD549 is an ultralow input bias current operational amplifier with features such as ultralow input bias current, low offset voltage and drift, low power consumption, etc. It is suitable for applications such as current amplifiers, photodiode preamplifiers, pH electrode buffer amplifiers, etc.
The AD549 is a monolithic electrometer operational amplifier designed for applications that require extremely low input bias current and low offset voltage, such as electrometer amplifiers, photodiode preamps, and pH or oxygen sensors. It uses Analog Devices' Topgate™ JFET technology and is offered in several performance grades (J, K, L, S) and a TO‑99 hermetic package.
The datasheet provides full electrical specifications, absolute maximum ratings, typical performance curves, and mechanical data. It also includes connection diagrams, product highlights, revision history and ordering information for designers who need precise bias‑current performance and low noise.
| Input bias current (max) | 250 fA |
|---|---|
| Input offset voltage (max) | 0.25 mV |
The AD549L version has a maximum input bias current of 250 fA, while the AD549J version is limited to 250 fA as well.
The AD549 is available in a TO‑99 hermetic package.