Overview
The AD549SH/883B is a monolithic electrometer operational amplifier produced by Analog Devices Inc. It is renowned for its ultralow input bias current, making it ideal for applications requiring high precision and low noise. The AD549 utilizes Topgate™ JFET technology, which ensures extremely low input current and is compatible with standard junction isolated bipolar processes. This amplifier is laser trimmed for precision performance, offering low input offset voltage and drift. It is available in a TO-99 hermetic package and is rated over the military temperature range of −55°C to +125°C, adhering to MIL-STD-883B, Rev. C standards.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Bias Current | 100 fA (AD549K), 250 fA (AD549J) | A |
| Input Offset Voltage | 0.50 mV (AD549K), 1.00 mV (AD549J) | mV |
| Input Offset Voltage Drift | 15 μV/°C (AD549K), 20 μV/°C (AD549J) | μV/°C |
| Supply Current | 700 μA | μA |
| Unity-Gain Bandwidth | 1 MHz | Hz |
| Slew Rate | 3 V/μs | V/μs |
| Supply Voltage | ±18 V | V |
| Operating Temperature Range | −55°C to +125°C (AD549S) | °C |
| Package Type | TO-99 Hermetic |
Key Features
- Ultralow input bias current achieved with Topgate™ JFET technology.
- Laser-trimmed input offset voltage and drift for precision performance.
- Low power consumption with a maximum quiescent supply current of 700 μA.
- High accuracy with low input offset voltage and drift.
- Pin compatible with standard FET and electrometer op amps, allowing for easy system upgrades.
- Available in military-grade packaging with extended reliability and screening options.
Applications
- Electrometer amplifier.
- Photodiode preamplifier.
- pH electrode buffer.
- Precision integrator or low droop sample-and-hold circuits.
- Preamplifier for current output transducers such as photomultiplier tubes or oxygen sensors.
Q & A
- What is the primary feature of the AD549SH/883B operational amplifier?
The AD549SH/883B is primarily known for its ultralow input bias current, achieved through Topgate™ JFET technology.
- What are the input offset voltage and drift specifications for the AD549K and AD549J versions?
The AD549K has an input offset voltage of 0.50 mV and a drift of 15 μV/°C, while the AD549J has an input offset voltage of 1.00 mV and a drift of 20 μV/°C.
- What is the maximum supply current of the AD549SH/883B?
The maximum quiescent supply current is 700 μA.
- What is the unity-gain bandwidth and slew rate of the AD549SH/883B?
The unity-gain bandwidth is 1 MHz, and the slew rate is 3 V/μs.
- What are the operating temperature ranges for the different versions of the AD549?
The AD549J, AD549K, and AD549L are rated over the commercial temperature range of 0°C to +70°C, while the AD549S is rated over the military temperature range of −55°C to +125°C.
- What type of package is the AD549SH/883B available in?
The AD549SH/883B is available in a TO-99 hermetic package.
- What are some common applications of the AD549SH/883B?
Common applications include electrometer amplifiers, photodiode preamplifiers, pH electrode buffers, and precision integrators or low droop sample-and-hold circuits.
- Is the AD549SH/883B compatible with other FET and electrometer op amps?
Yes, the AD549SH/883B is pin compatible with standard FET and electrometer op amps, allowing for easy upgrades in existing systems.
- What kind of screening and reliability options are available for the AD549SH/883B?
The AD549SH/883B is available with extended reliability and screening options, including 168-hour burn-in and other environmental and physical tests derived from MIL-STD-883B, Rev. C.
- What is the significance of the Topgate™ JFET technology used in the AD549SH/883B?
The Topgate™ JFET technology ensures extremely low input current and is compatible with standard junction isolated bipolar processes, enhancing the overall performance of the amplifier.
