Part A
AD549JHZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 3803 個数
- Package
- TO-99-8
- Series
- リニアアンプ - 計装用、オペアンプ、バッファアンプ
Replacement verdict
Compatible functional replacement candidate
The AD549JHZ and AD549KHZ are functionally equivalent electrometer-grade operational amplifiers that share the same core architecture, package footprint, and pin configuration. The AD549KHZ offers a higher grade specification with tighter input offset voltage and lower input bias current, making it a viable direct replacement for the AD549JHZ in most precision applications where enhanced DC performance is beneficial. Both devices are interchangeable at the board level without layout modifications.
Package Type
High match
Pin Configuration
High match
Input Offset Voltage
High match
Input Bias Current
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 | AD549JHZ | AD549KHZ | Why it matters |
|---|---|---|---|
| Input Offset Voltage (VOS) | 1 mV max | 0.5 mV max | Lower offset voltage reduces DC error in precision electrometer and high-impedance measurement circuits. |
| Input Offset Voltage Drift (TCVOS) | 20 µV/°C max | 10 µV/°C max | Lower drift improves stability over temperature, critical for long-term precision measurements. |
| Input Bias Current (IB) | 150 fA max | 75 fA max | Ultra-low bias current is essential for high-impedance sensors, pH probes, and electrometer applications. |
| Input Offset Current (IOS) | 75 fA max | 40 fA max | Lower offset current reduces error in differential high-impedance measurements. |
| Input Noise Voltage Density | 90 nV/√Hz at 1 kHz | 90 nV/√Hz at 1 kHz | Noise density affects resolution in low-level signal amplification. |
| Gain Bandwidth Product (GBW) | 1 MHz typ | 1 MHz typ | Determines the bandwidth available for signal conditioning and closed-loop stability. |
| Common-Mode Rejection Ratio (CMRR) | 90 dB min | 90 dB min | High CMRR rejects common-mode interference in precision instrumentation. |
| Power Supply Rejection Ratio (PSRR) | 90 dB min | 90 dB min | Good PSRR minimizes supply noise coupling into the signal path. |
| Operating Temperature Range | 0°C to +70°C | 0°C to +70°C | Defines the environment where the part maintains specified electrical performance. |
| Package | TO-99-8 (H) | TO-99-8 (H) | Package affects thermal behavior, mounting, and availability for replacement designs. |
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 | AD549KHZ |
|---|---|---|
| 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 | 0.075 pA |
| Voltage - Input Offset | 500 µV | 150 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 AD549KHZ?
The AD549JHZ and AD549KHZ are both ultralow input bias current operational amplifiers from Analog Devices. The primary difference is their specified electrical performance grades. The AD549JHZ is the lower grade, while the AD549KHZ is the higher grade, offering tighter specifications for input offset voltage, input offset voltage drift, and input bias current. Both are housed in the same 8-lead TO-99 hermetic metal can package and are specified over the 0°C to +70°C commercial temperature range.
Are the AD549JHZ and AD549KHZ pin-compatible?
Yes. Both the AD549JHZ and AD549KHZ are offered in the same 8-lead TO-99 package (H-8). The pinout is identical, with pins for offset null, inverting input, non-inverting input, V-, output, and V+. This allows the AD549KHZ to be used as a direct replacement for the AD549JHZ on an existing PCB, provided the tighter specifications of the KHZ grade are acceptable or required.
Which grade has better input offset voltage specifications?
The AD549KHZ has tighter input offset voltage specifications than the AD549JHZ. According to the Analog Devices datasheet, the AD549JHZ has a maximum input offset voltage of 1.0 mV at 25°C, while the AD549KHZ has a maximum input offset voltage of 0.5 mV at 25°C. The KHZ grade also offers a lower maximum input offset voltage drift over temperature.
How do the input bias current specifications compare between the AD549JHZ and AD549KHZ?
Both grades feature extremely low input bias current, which is the defining characteristic of the AD549. The AD549JHZ has a maximum input bias current of 100 fA at 25°C, while the AD549KHZ has a maximum input bias current of 60 fA at 25°C. The KHZ grade provides a tighter guaranteed limit for this critical parameter.
Can the AD549JHZ and AD549KHZ be used interchangeably in a design?
In many applications, the AD549JHZ and AD549KHZ can be used interchangeably because they share the same package, pinout, and functional behavior. However, the AD549KHZ offers tighter guaranteed limits for input offset voltage, offset voltage drift, and input bias current. A design that requires the tighter specifications of the KHZ grade may not function correctly with the JHZ grade. Always verify that the lower-grade part meets the system requirements before substituting.
What is the operating temperature range for the AD549JHZ and AD549KHZ?
Both the AD549JHZ and AD549KHZ 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 packages of the AD549 may be available, but the JHZ and KHZ suffixes specifically denote the commercial temperature range in the TO-99 package.
Do the AD549JHZ and AD549KHZ require external offset nulling?
Both the AD549JHZ and AD549KHZ provide pins for external offset nulling. The need for offset nulling depends on the application's tolerance for input offset voltage. The AD549KHZ has a lower maximum offset voltage, so it may not require nulling in less demanding applications. The AD549JHZ, with a higher maximum offset, may require nulling in precision applications. The offset null circuit is the same for both grades.
Are the AD549JHZ and AD549KHZ RoHS compliant?
The AD549JHZ and AD549KHZ are both available in lead-free, RoHS-compliant versions. The "Z" suffix in the part number indicates a RoHS-compliant package. However, because these are hermetic metal can packages, the RoHS compliance status should be confirmed with the manufacturer's current datasheet or product page, as exemptions may apply. Always verify the specific ordering code for the latest compliance information.