Overview
The AD549JHZ is a monolithic electrometer operational amplifier produced by Analog Devices Inc. It is renowned for its ultralow input bias current, achieved through Analog Devices' exclusive Topgate™ JFET technology. This amplifier is designed for applications requiring very low input current and low input offset voltage, making it ideal for precision instrumentation and measurement systems.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Bias Current | - | 60 fA | 100 fA | A |
| Input Offset Voltage | - | 0.5 mV | 1 mV | mV |
| Input Offset Voltage Drift | - | 15 μV/°C | 20 μV/°C | μV/°C |
| Unity Gain Bandwidth | 0.7 | 1.0 | - | MHz |
| Slew Rate | 2 | 3 | - | V/μs |
| Settling Time (0.1%) | - | 4.5 | - | μs |
| Supply Voltage | - | - | ±18 V | V |
| Operating Temperature Range (AD549JHZ) | 0°C | - | +70°C | °C |
Key Features
- Ultralow input bias current using Topgate™ JFET technology.
- Laser-trimmed input offset voltage and drift for precision performance.
- High common-mode impedance (1015 Ω) ensuring input current independence from common-mode voltage.
- Low quiescent supply current (700 μA) to minimize heating effects.
- Pin compatibility with standard FET and electrometer op amps for easy system upgrades.
- Available in a TO-99 hermetic package with the case connected to Pin 8 for reduced stray leakage.
Applications
- Precision preamplification for current output transducers such as photodiodes, photomultiplier tubes, and oxygen sensors.
- Precision integrators and low droop sample-and-hold circuits.
- High-precision instrumentation and measurement systems requiring low input bias current and offset voltage.
Q & A
- What is the primary technology used in the AD549JHZ to achieve low input bias current?
The AD549JHZ uses Analog Devices' exclusive Topgate™ JFET technology to achieve ultralow input bias current. - What are the typical input offset voltage and drift specifications for the AD549JHZ?
The typical input offset voltage is 0.5 mV, and the drift is 15 μV/°C for the AD549K version. - What is the unity gain bandwidth of the AD549JHZ?
The unity gain bandwidth is typically 1 MHz. - What is the slew rate of the AD549JHZ?
The slew rate is typically 3 V/μs. - What is the operating temperature range for the AD549JHZ?
The operating temperature range is 0°C to +70°C. - What type of package is the AD549JHZ available in?
The AD549JHZ is available in a TO-99 hermetic package. - Can the AD549JHZ be used as a precision integrator?
Yes, the AD549JHZ can be used as a precision integrator due to its low input bias current and offset voltage. - Is the AD549JHZ pin compatible with other FET and electrometer op amps?
Yes, the AD549JHZ is pin compatible with standard FET and electrometer op amps, allowing for easy system upgrades. - What is the maximum supply voltage for the AD549JHZ?
The maximum supply voltage is ±18 V. - What is the quiescent supply current of the AD549JHZ?
The quiescent supply current is a maximum of 700 μA.
