OPA128JM Equivalent & Substitute Parts Reference

Part Overview

The OPA128JM is a general-purpose operational amplifier manufactured by Texas Instruments in a TO-99-8 metal can package. This device is classified as obsolete, though 2200 units remain in current inventory. The OPA128JM operates as a single-circuit amplifier with JFET input technology, delivering 1 MHz gain-bandwidth product and ultra-low input bias current of 0.15 pA, making it suitable for precision instrumentation and high-impedance signal conditioning applications.

Due to its obsolete status, identifying equivalent and substitute parts is essential for design continuity, long-term supply chain planning, and new product development. Substitute parts must maintain electrical compatibility within the specified parameter ranges while accommodating potential package and performance differences.

Substiute Parts

OPA128JM

Texas InstrumentsIn Stock: 2216OPA128JM Datasheet

Current PartRFQ

OPA145ID

Texas InstrumentsIn Stock: 2413OPA145ID Datasheet

MFR RecommendedRFQ

AD549JHZ

Analog Devices Inc.In Stock: 8241AD549JHZ Datasheet

MFR RecommendedRFQ

AD549SH/883B

Analog Devices Inc.In Stock: 1386AD549SH/883B Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OPA128JM is determined by electrical parameter compatibility and package form factor. The primary substitution criteria are:

Electrical Compatibility Parameters:

• Slew Rate: 3 V/µs (baseline performance)
• Gain Bandwidth Product: 1 MHz (frequency response)
• Input Bias Current: 0.15 pA (ultra-low leakage requirement)
• Supply Voltage Range: 10 V to 36 V (operating envelope)
• Output Current Capability: minimum 10 mA per channel
• Input Offset Voltage: within acceptable instrumentation limits

Package Compatibility:

• TO-99-8 Metal Can (through-hole mounting) for direct pin-compatible replacement
• 8-SOIC surface-mount package for redesign scenarios requiring modern packaging

Operational Temperature Range:

• Commercial grade (0°C to 70°C) for standard applications
• Military grade (-55°C to 125°C) for extended temperature requirements

The substitute parts listed maintain the core electrical characteristics of the OPA128JM while offering either identical packaging for direct replacement or enhanced performance specifications with alternative packaging for new designs.

Parameter Comparison

Engineering Selection Recommendations

Direct Pin-Compatible Replacement (TO-99-8 Package):

The AD549JHZ and AD549SH/883B are direct electrical and mechanical substitutes for the OPA128JM in through-hole applications. Both devices maintain the TO-99-8 metal can package, identical pin configuration, and compatible electrical specifications. The AD549JHZ is recommended for commercial-grade applications requiring 0°C to 70°C operation with active product status and unlimited moisture sensitivity. The AD549SH/883B is specified for military-grade applications requiring extended temperature operation (-55°C to 125°C) and MIL-STD-883 qualification, with superior input bias current performance (0.075 pA).

Surface-Mount Alternative (8-SOIC Package):

The OPA145ID provides enhanced electrical performance with 5.5 MHz gain-bandwidth product and 20 V/µs slew rate, suitable for applications requiring higher frequency response. This device operates across an extended temperature range (-40°C to 125°C) and features rail-to-rail output capability. The OPA145ID requires PCB redesign due to surface-mount packaging but offers improved performance metrics and active product status. Moisture sensitivity level MSL 2 (1 Year) requires standard handling procedures.

Compliance and Regulatory Status:

All substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the regulatory profile of the OPA128JM. Selection between substitutes depends on application requirements: package form factor (through-hole versus surface-mount), temperature operating range (commercial versus military), and performance specifications (bandwidth and slew rate).

Frequently Asked Questions (FAQ)

Q: Can the AD549JHZ directly replace the OPA128JM in existing PCB designs?

A: Yes. The AD549JHZ maintains identical TO-99-8 metal can packaging, pin configuration, and electrical specifications within the OPA128JM operating envelope. No PCB modifications are required for direct substitution in through-hole applications.

Q: What is the primary difference between AD549JHZ and AD549SH/883B?

A: Both devices share identical electrical specifications and TO-99-8 packaging. The AD549SH/883B is qualified to MIL-STD-883 military standards with extended operating temperature range (-55°C to 125°C) and superior input bias current (0.075 pA versus 0.15 pA). The AD549JHZ is specified for commercial applications (0°C to 70°C).

Q: Why would I select the OPA145ID over the AD549JHZ?

A: The OPA145ID offers enhanced performance specifications: 5.5 MHz gain-bandwidth product (versus 1 MHz), 20 V/µs slew rate (versus 3 V/µs), and rail-to-rail output capability. Selection requires PCB redesign due to 8-SOIC surface-mount packaging. The OPA145ID is suitable for applications requiring higher frequency response and modern manufacturing processes.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The OPA128JM, AD549JHZ, AD549SH/883B, and OPA145ID are all ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Q: What is the moisture sensitivity level difference between OPA145ID and other substitutes?

A: The OPA145ID has MSL 2 (1 Year), requiring standard moisture control during storage and handling. The OPA128JM, AD549JHZ, and AD549SH/883B have MSL 1 (Unlimited), allowing indefinite storage without moisture control measures. MSL 2 components require baking before reflow soldering if storage exceeds one year.

Q: Can the OPA145ID be used in applications requiring 0°C to 70°C operation?

A: Yes. The OPA145ID operates across -40°C to 125°C, which encompasses the 0°C to 70°C commercial range. However, the extended temperature capability is not required for commercial-grade applications and does not provide cost or performance advantage in this scenario.

Q: What supply voltage range is compatible across all substitute parts?

A: All substitute parts operate within the 10 V to 36 V supply range specified for the OPA128JM. The OPA145ID extends the minimum supply voltage to 4.5 V, providing additional flexibility for low-voltage applications.