LF398MX Sample and Hold Amplifier IC

Part Overview

The LF398MX is a Sample and Hold Amplifier integrated circuit manufactured by Texas Instruments, designed for precision analog signal acquisition and storage applications. This device features a single sample-and-hold circuit in a 14-SOIC surface mount package, enabling accurate sampling of analog signals at specified time intervals.

The LF398MX carries an Obsolete product status, indicating that Texas Instruments has discontinued active production and support for this part number. Organizations currently using this component in active designs or requiring replacement units for maintenance and repair operations must identify suitable alternatives to ensure long-term supply chain continuity and design sustainability.

Substiute Parts

LF398MX

Texas InstrumentsIn Stock: 24443LF398MX Datasheet

Current PartRFQ

LF398MX/NOPB

Texas InstrumentsIn Stock: 25324LF398MX/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LF398MX is determined by strict equivalence across all critical electrical and mechanical parameters. The substitute relationship is established based on the following criteria:

Electrical Parameter Equivalence:

• Amplifier Type: Sample and Hold (identical function)
• Number of Circuits: 1 (identical circuit count)
• Current - Input Bias: 10 nA (identical specification)
• Voltage - Input Offset: 2 mV (identical specification)
• Current - Supply: 4.5 mA (identical specification)
• Voltage - Supply Span: 10 V to 36 V (identical operating range)
• Operating Temperature Range: 0°C to 70°C (identical range)

Mechanical Parameter Equivalence:

• Mounting Type: Surface Mount (identical mounting method)
• Package / Case: 14-SOIC (0.154", 3.90mm Width) (identical package)
• Moisture Sensitivity Level: 1 (Unlimited) (identical MSL rating)

The substitute part maintains complete functional and physical compatibility with the original LF398MX, enabling direct replacement in existing circuit designs without modification to PCB layouts, component footprints, or electrical connections.

Parameter Comparison

Engineering Selection Recommendations

The LF398MX/NOPB is the direct functional and physical equivalent of the obsolete LF398MX. Selection of the LF398MX/NOPB is based on the following engineering factors:

Product Status Consideration: The LF398MX carries Obsolete status, indicating discontinued production by Texas Instruments. The LF398MX/NOPB maintains Active product status with confirmed inventory availability (25,300 pieces in stock), ensuring reliable supply for current and future procurement requirements.

Regulatory Compliance: The LF398MX/NOPB achieves ROHS3 Compliant certification, representing improved environmental and regulatory alignment compared to the RoHS non-compliant status of the original LF398MX. This compliance enhancement supports modern manufacturing standards and regulatory requirements in target markets.

Electrical and Mechanical Equivalence: All critical electrical parameters (input bias current, input offset voltage, supply current, supply voltage range, operating temperature) and mechanical specifications (surface mount package, 14-SOIC form factor, MSL rating) are identical between the two part numbers, enabling direct substitution without circuit redesign or PCB modification.

Packaging and Handling: Both parts maintain identical Moisture Sensitivity Level (MSL 1 - Unlimited), eliminating special storage or handling requirement changes during transition from the obsolete to the active part number.

Frequently Asked Questions (FAQ)

Q: Can the LF398MX/NOPB be used as a direct replacement for the LF398MX in existing designs?

A: Yes. The LF398MX/NOPB is electrically and mechanically equivalent to the LF398MX across all specified parameters. No circuit modifications, PCB layout changes, or component footprint adjustments are required for substitution.

Q: What is the difference between LF398MX and LF398MX/NOPB?

A: The primary differences are product status and RoHS compliance. The LF398MX is Obsolete with RoHS non-compliant status, while the LF398MX/NOPB is Active with ROHS3 Compliant certification. All electrical and mechanical specifications remain identical.

Q: Are there any supply chain advantages to using LF398MX/NOPB?

A: Yes. The LF398MX/NOPB maintains Active product status with confirmed inventory availability (25,300 pieces), whereas the LF398MX is Obsolete with no active production. The LF398MX/NOPB ensures long-term supply continuity and reduces procurement risk.

Q: Does the LF398MX/NOPB require different PCB footprint or mounting considerations?

A: No. Both parts use identical 14-SOIC surface mount packaging with 0.154" (3.90mm) width. PCB footprints, land patterns, and mounting procedures remain unchanged.

Q: What is the significance of the "/NOPB" suffix in LF398MX/NOPB?

A: The "/NOPB" suffix indicates the part is supplied in Cut Tape (CT) and Digi-Reel® packaging formats without lead-free plating on the leads. This designation distinguishes the packaging configuration from other variants of the base LF398 product.

Q: Are the operating temperature ranges identical between the two parts?

A: Yes. Both the LF398MX and LF398MX/NOPB operate across the identical temperature range of 0°C to 70°C, with no thermal performance differences.

Q: What compliance certifications apply to the LF398MX/NOPB?

A: The LF398MX/NOPB holds ROHS3 Compliant and REACH Unaffected certifications. Both parts share identical ECCN (EAR99) and HTSUS (8542.33.0001) classifications for export and tariff purposes.