LF198AH Sample and Hold Amplifier Equivalent & Substitute Parts

Part Overview

The LF198AH is a Sample and Hold Amplifier integrated circuit manufactured by Texas Instruments, housed in a TO-99-8 metal can package. This linear amplifier device is classified as obsolete, indicating discontinued production by the manufacturer. The LF198AH performs precision sampling and holding of analog signals with a single circuit configuration, making it essential for data acquisition and signal conditioning applications.

Due to its obsolete status, identifying equivalent and substitute parts is necessary for system maintenance, repair, and redesign efforts. The substitute part LF198AH/NOPB maintains identical electrical and mechanical specifications while offering active product status and improved availability.

Substiute Parts

LF198AH

Texas InstrumentsIn Stock: 1521LF198AH Datasheet

Current PartRFQ

LF198AH/NOPB

Texas InstrumentsIn Stock: 1566LF198AH/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LF198AH is determined by strict equivalence across all critical electrical and mechanical parameters. The substitute part LF198AH/NOPB is classified as a direct equivalent based on the following criteria:

Electrical Parameter Equivalence:

• Amplifier Type: Sample and Hold (identical)
• Number of Circuits: 1 (identical)
• Current - Input Bias: 5 nA (identical)
• Voltage - Input Offset: 1 mV (identical)
• Current - Supply: 4.5 mA (identical)
• Voltage - Supply Span: 10 V to 36 V (identical)
• Operating Temperature Range: -55°C to 125°C (identical)

Mechanical and Package Equivalence:

• Mounting Type: Through Hole (identical)
• Package / Case: TO-99-8 Metal Can (identical)
• Supplier Device Package: TO-99-8 (identical)

Compliance and Certification Equivalence:

• RoHS Status: ROHS3 Compliant (identical)
• Moisture Sensitivity Level: 1 (Unlimited) (identical)
• REACH Status: REACH Unaffected (identical)
• ECCN: EAR99 (identical)

The LF198AH/NOPB differs only in product status (Active versus Obsolete) and packaging designation (Bulk), with no impact on functional or physical compatibility.

Parameter Comparison

Engineering Selection Recommendations

For LF198AH Replacement:

The LF198AH/NOPB is the direct substitute for the obsolete LF198AH. Both parts are manufactured by Texas Instruments and maintain identical electrical specifications, thermal operating range, and physical packaging. The substitute part carries Active product status, ensuring continued availability and supply chain reliability.

Compliance Considerations:

Both the LF198AH and LF198AH/NOPB maintain ROHS3 compliance and REACH Unaffected status, satisfying regulatory requirements for electronic component procurement in regulated industries. Moisture Sensitivity Level 1 (Unlimited) indicates no special handling or storage requirements beyond standard component care.

Availability and Inventory:

The LF198AH/NOPB demonstrates superior inventory availability (1531 pieces in stock) compared to the obsolete LF198AH (1414 pieces in stock). For new designs or system redesigns, the LF198AH/NOPB is the appropriate selection due to its Active product status.

Package and Mounting:

Both parts utilize identical TO-99-8 metal can through-hole packaging. PCB layout, footprint, and mounting procedures remain unchanged between the two parts, enabling direct substitution without circuit board redesign.

Frequently Asked Questions (FAQ)

Q: Can LF198AH/NOPB be used as a direct replacement for LF198AH in existing designs?

A: Yes. The LF198AH/NOPB is electrically and mechanically identical to the LF198AH across all specified parameters. Pin configuration, electrical performance, and thermal characteristics are equivalent. Direct substitution is supported without circuit modification.

Q: What does the "/NOPB" suffix indicate in the part number LF198AH/NOPB?

A: The "/NOPB" suffix designates "No Plumbum" (lead-free) packaging and indicates the part is supplied in bulk packaging format rather than tape-and-reel or other specialized packaging. This designation reflects RoHS3 compliance and standard commercial packaging practices.

Q: Are there any thermal or electrical performance differences between LF198AH and LF198AH/NOPB?

A: No. Both parts operate identically across the specified temperature range (-55°C to 125°C) and maintain identical electrical characteristics including input bias current (5 nA), input offset voltage (1 mV), and supply current (4.5 mA).

Q: Why is the LF198AH classified as obsolete?

A: The LF198AH has been discontinued by Texas Instruments. The LF198AH/NOPB remains in active production and is the recommended part for new applications and system redesigns.

Q: What is the significance of the TO-99-8 metal can package?

A: The TO-99-8 metal can is a through-hole package with 8 pins, commonly used for precision analog circuits. This package provides excellent electromagnetic shielding and thermal characteristics suitable for sample-and-hold amplifier applications. Both the LF198AH and LF198AH/NOPB use this identical package.

Q: Are there any supply voltage or temperature derating considerations?

A: The LF198AH and LF198AH/NOPB operate across a supply voltage range of 10 V to 36 V and a temperature range of -55°C to 125°C. No special derating is specified in the provided parameters. System design should ensure operation within these specified limits.

Q: What is Moisture Sensitivity Level 1 (Unlimited)?

A: MSL 1 (Unlimited) indicates the component has no moisture sensitivity restrictions. Standard component storage and handling practices are sufficient. No special dry-pack storage or baking procedures are required prior to assembly.