Part A
AD549JHZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3803 Stückzahl
- Package
- TO-99-8
- Series
- Linear-Verstärker.Instrumentation, OP-Verstärker, Pufferverstärker
Replacement verdict
Compatible functional replacement candidate
The AD549JHZ and AD549LH are both electrometer-grade operational amplifiers from the same AD549 family, sharing identical core electrical characteristics including ultra-low input bias current, low offset voltage, and unity-gain stability. The AD549LH offers a tighter offset voltage grade and an extended temperature range, making it a viable functional replacement for the AD549JHZ in most precision electrometer applications, provided the operating environment and offset requirements are validated against the target design.
Input Bias Current
High match
Offset Voltage Grade
High match
Package Type
High match
Operating Temperature Range
Validation required
Parts at a glance
Part B
AD549LH
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2715 Stückzahl
- Package
- TO-99-8
- Series
- Linear-Verstärker.Instrumentation, OP-Verstärker, Pufferverstärker
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD549JHZ | AD549LH | Why it matters |
|---|---|---|---|
| Input Offset Voltage (Max) | 1 mV | 0.5 mV | Lower offset voltage improves DC accuracy in precision electrometer and low-level signal applications. |
| Input Offset Voltage Drift (Max) | 20 µV/°C | 10 µV/°C | Lower drift maintains accuracy over temperature, critical for stable measurements in varying environments. |
| Input Bias Current (Max, 25°C) | 150 fA | 75 fA | Ultra-low bias current is essential for high-impedance sensors, pH probes, and electrometer front ends. |
| Input Bias Current (Max, 125°C) | 300 fA | 150 fA | Bias current at elevated temperature determines usability in high-temperature precision instrumentation. |
| Input Offset Current (Max, 25°C) | 75 fA | 40 fA | Lower offset current reduces error in differential high-impedance measurement configurations. |
| Input Voltage Noise (0.1 Hz to 10 Hz) | 4 µV p-p | 4 µV p-p | Low-frequency noise limits resolution in DC-coupled precision measurement systems. |
| Gain Bandwidth Product | 1 MHz | 1 MHz | Determines closed-loop bandwidth achievable at a given gain in signal conditioning circuits. |
| Common-Mode Rejection Ratio (Min) | 90 dB | 90 dB | High CMRR rejects common-mode interference, preserving accuracy in bridge and sensor interfaces. |
| Operating Temperature Range | 0°C to 70°C | -40°C to 125°C | The wider industrial temperature range of the LH grade enables use in harsh-environment and military-grade applications. |
| Package | TO-99 (H) | TO-99 (H) | Package compatibility ensures drop-in replacement without PCB redesign. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD549JHZ | AD549LH |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | Topgate™ | Topgate™ |
| Part Status | Active | Obsolete |
| Amplifier Type | General Purpose | General Purpose |
| Number of Circuits | 1 | 1 |
| Slew Rate | 3V/µs | 3V/µs |
| Gain Bandwidth Product | 1 MHz | 1 MHz |
| Current - Input Bias | 0.15 pA | 0.04 pA |
| Voltage - Input Offset | 500 µV | 300 µV |
| Supply Current | 600µA | 600µA |
| Current - Output / Channel | 20 mA | 20 mA |
| Voltage - Supply Span(Min) | 10 V | 10 V |
| Voltage - Supply Span(Max) | 36 V | 36 V |
| Operating Temperature | 0°C ~ 70°C | 0°C ~ 70°C |
| Mounting Type | Through Hole | Through Hole |
Frequently asked questions
What are the main differences between the AD549JHZ and the AD549LH?
The AD549JHZ and AD549LH are both ultralow input bias current operational amplifiers from Analog Devices. The primary difference is their specified operating temperature range and corresponding electrical specifications. The AD549JHZ is specified over the commercial temperature range of 0°C to +70°C, while the AD549LH is specified over the industrial temperature range of -40°C to +85°C. Both are available in the same 8-lead TO-99 hermetic metal can package.
Are the AD549JHZ and AD549LH pin-compatible?
Yes. Both the AD549JHZ and AD549LH are offered in the same 8-lead TO-99 package (also designated as H-8 or J-8 style depending on the manufacturer's package code). They share identical pinout configurations, allowing for direct PCB footprint compatibility when the temperature grade is not a constraint.
What is the input bias current specification for these devices?
The AD549 series is characterized by ultralow input bias current. The AD549JHZ and AD549LH both feature a maximum input bias current of 60 fA at +25°C, with typical values of 40 fA. This makes them suitable for applications requiring extremely high input impedance, such as photodiode preamplifiers and electrometer circuits.
Can the AD549JHZ be used as a direct replacement for the AD549LH in an existing design?
Electrical and pin compatibility is maintained, but the substitution depends on the operating temperature requirements of the application. The AD549JHZ is specified only from 0°C to +70°C, whereas the AD549LH is specified from -40°C to +85°C. If the application operates outside the commercial temperature range, the AD549JHZ is not a valid replacement. Within the commercial range, the AD549JHZ may be used, but the designer must verify that all other specifications meet the system requirements.
What are the input offset voltage and drift specifications for the AD549JHZ and AD549LH?
Both the AD549JHZ and AD549LH have a maximum input offset voltage of 1.0 mV at +25°C. The input offset voltage drift is typically 10 µV/°C for both grades. These specifications are identical across the two temperature grades, meaning the offset performance does not differ between the J and L versions.
What is the gain bandwidth product of the AD549JHZ and AD549LH?
The AD549JHZ and AD549LH both have a typical gain bandwidth product of 1 MHz. This specification is common to the entire AD549 series and is not affected by the temperature grade designation.
What are the power supply requirements for the AD549JHZ and AD549LH?
Both the AD549JHZ and AD549LH operate from dual power supplies with a specified range of ±5 V to ±18 V. The typical supply current is 0.7 mA per amplifier. These power supply specifications are identical for both temperature grades.
Which applications are best suited for the AD549LH over the AD549JHZ?
The AD549LH is better suited for applications that require operation over the industrial temperature range of -40°C to +85°C, such as industrial process control, outdoor instrumentation, and automotive test equipment. The AD549JHZ is appropriate for benchtop laboratory equipment, commercial-grade data acquisition systems, and other applications confined to 0°C to +70°C.