Part A
AD549JHZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3803 PCS
- Package
- TO-99-8
- Series
- Linear - Amplifiers - Instrumentation, OP Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD549LHZ and AD549JHZ are functionally equivalent electrometer-grade operational amplifiers that share the same core architecture, package, and pinout. The AD549LHZ offers tighter input offset voltage and offset voltage drift specifications, making it the preferred choice for applications demanding the highest DC precision. Both devices are viable substitutes in the same circuit, provided the designer validates that the AD549JHZ's looser offset limits remain acceptable for the target application.
Input Offset Voltage Grade
Validation required
Package Type
High match
Pin Configuration
High match
Operating Temperature Range
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD549LHZ | AD549JHZ | Why it matters |
|---|---|---|---|
| Input Offset Voltage (VOS) max | 0.5 mV | 1.0 mV | Lower offset voltage improves DC accuracy in precision electrometer and low-level signal applications. |
| Input Offset Voltage Drift (TCVOS) max | 10 µV/°C | 20 µV/°C | Lower drift maintains accuracy over temperature, critical for stable long-term measurements. |
| Input Bias Current (IB) max | 60 fA | 150 fA | Ultra-low bias current is essential for high-impedance sensors, pH probes, and electrometer front ends. |
| Input Offset Current (IOS) max | 30 fA | 75 fA | Lower offset current reduces error in high-source-impedance measurement circuits. |
| Input Noise Voltage (0.1 Hz to 10 Hz) typ | 4 µV p-p | 4 µV p-p | Low 1/f noise is important for resolving small DC signals in precision instrumentation. |
| Common-Mode Rejection Ratio (CMRR) min | 90 dB | 80 dB | Higher CMRR rejects common-mode interference, improving accuracy in noisy environments. |
| Power Supply Rejection Ratio (PSRR) min | 90 dB | 80 dB | Better PSRR reduces sensitivity to supply variations, aiding precision performance. |
| Operating Temperature Range | -40 °C to +85 °C | 0 °C to +70 °C | Wider temperature range enables use in industrial and outdoor applications. |
| Package / Grade | TO-99, L Grade (industrial) | TO-99, J Grade (commercial) | Grade determines guaranteed specifications and suitable application environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD549JHZ | AD549LHZ |
|---|---|---|
| Series | Topgate™ | Topgate™ |
| Part Status | Active | Active |
| 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 AD549LHZ and AD549JHZ?
The AD549LHZ and AD549JHZ are both ultralow input bias current operational amplifiers from Analog Devices. The primary difference is their specified input offset voltage (Vos) grade. The AD549LHZ is the higher-grade version with a maximum input offset voltage of 1.0 mV, while the AD549JHZ has a maximum input offset voltage of 2.0 mV. Both are specified over the commercial temperature range and are available in a TO-99 hermetic metal can package.
Are the AD549LHZ and AD549JHZ pin-compatible?
Yes. Both the AD549LHZ and AD549JHZ are offered in the same TO-99 (H-08) hermetic metal can package with identical pin configurations. This allows them to be used interchangeably on the same PCB footprint without layout changes.
What is the input bias current specification for the AD549LHZ and AD549JHZ?
Both the AD549LHZ and AD549JHZ feature an ultralow maximum input bias current of 60 fA (0.06 pA) at 25°C, making them suitable for electrometer-grade applications. The typical input bias current is 10 fA at 25°C. These specifications are identical for both grades.
Can the AD549JHZ be used as a direct replacement for the AD549LHZ?
In many applications, yes, because both share the same pinout, package, and most electrical specifications. However, the AD549JHZ has a looser maximum input offset voltage (2.0 mV vs. 1.0 mV for the AD549LHZ). If the circuit requires the tighter offset voltage guaranteed by the L grade, the J grade may not meet the design margin without recalibration or offset trimming.
What is the operating temperature range for the AD549LHZ and AD549JHZ?
Both the AD549LHZ and AD549JHZ are specified for the commercial temperature range of 0°C to +70°C. They are not specified for industrial or military temperature ranges. For extended temperature operation, other grades or models would be required.
Do the AD549LHZ and AD549JHZ differ in input offset voltage drift?
Yes. The AD549LHZ has a maximum input offset voltage drift of 5 µV/°C, while the AD549JHZ has a maximum drift of 10 µV/°C. This difference is a direct consequence of the offset voltage grade and should be considered in precision applications where temperature stability is critical.
Are the AD549LHZ and AD549JHZ RoHS compliant?
The AD549LHZ and AD549JHZ are both available in lead-free, RoHS-compliant versions. The "Z" suffix in the part number indicates a RoHS-compliant package. However, designers should verify the specific ordering code and manufacturer documentation to confirm compliance for their exact lot or date code.
What are the common applications for the AD549LHZ and AD549JHZ?
Both grades are used in applications requiring ultralow input bias current, such as electrometer amplifiers, photodiode preamplifiers, pH electrode buffers, ionization chambers, and vacuum tube grid current measurement. The AD549LHZ is preferred where tighter offset voltage and lower drift are needed, while the AD549JHZ may be sufficient for less demanding precision requirements.