NJM79L18A Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The NJM79L18A is a linear voltage regulator IC manufactured by Nisshinbo Micro Devices Inc., designed to provide a fixed negative output voltage of -18V at 100mA. This device is classified as a Power Management (PMIC) component and is packaged in a TO-92-3 (TO-226-3) through-hole configuration. The NJM79L18A is currently listed as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and component procurement.

Substiute Parts

NJM79L18A

Nisshinbo Micro Devices Inc.In Stock: 2479NJM79L18A Datasheet

Current PartRFQ

MC79L18ACPG

onsemiIn Stock: 1256MC79L18ACPG Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the NJM79L18A is determined by the following critical parameters:

Output Voltage Matching: The substitute part must provide a fixed negative output voltage of -18V to maintain circuit functionality.

Output Current Rating: The substitute must support a minimum output current of 100mA to meet load requirements.

Package Compatibility: The substitute must use the TO-92-3 (TO-226-3) through-hole package to ensure mechanical and electrical compatibility with existing PCB layouts.

Output Configuration: The substitute must provide negative voltage regulation to match the original design topology.

Protection Features: The substitute must include over-temperature and short-circuit protection to maintain system reliability.

The MC79L18ACPG manufactured by onsemi meets all these critical substitution criteria and is classified as an active product with current manufacturing support.

Parameter Comparison

Engineering Selection Recommendations

The MC79L18ACPG is the qualified substitute for the obsolete NJM79L18A based on the following engineering criteria:

Functional Equivalence: Both devices provide identical output voltage (-18V) and current rating (100mA) with matching negative output configuration and fixed regulation topology.

Package Compatibility: Both parts use the TO-92-3 through-hole package, enabling direct PCB layout compatibility without redesign.

Protection Parity: Both devices incorporate over-temperature and short-circuit protection, maintaining equivalent system reliability.

Product Status: The MC79L18ACPG is an active product with current manufacturing support from onsemi, ensuring long-term component availability compared to the obsolete NJM79L18A.

Compliance Advantage: The MC79L18ACPG is ROHS3 compliant, whereas the NJM79L18A is non-compliant. This compliance status may be required for new designs or regulatory requirements.

Performance Considerations: The MC79L18ACPG has a lower maximum input voltage rating (-35V versus -40V) and reduced PSRR (48dB versus 60dB at 120Hz). These differences require circuit-level evaluation if the original design operates at the maximum input voltage specification or requires the higher PSRR performance of the NJM79L18A.

Frequently Asked Questions (FAQ)

Q: Can the MC79L18ACPG be used as a direct replacement for the NJM79L18A?

A: The MC79L18ACPG is functionally equivalent for applications within its specified operating parameters. Both devices provide -18V fixed negative regulation at 100mA in a TO-92-3 package. However, the MC79L18ACPG has a lower maximum input voltage rating (-35V versus -40V) and reduced PSRR (48dB versus 60dB). Verify that your circuit operates within the MC79L18ACPG specifications before substitution.

Q: What are the key differences between these two parts?

A: The primary differences are: (1) Product status—NJM79L18A is obsolete while MC79L18ACPG is active; (2) Maximum input voltage—NJM79L18A supports -40V while MC79L18ACPG supports -35V; (3) PSRR—NJM79L18A provides 60dB at 120Hz while MC79L18ACPG provides 48dB; (4) RoHS compliance—MC79L18ACPG is ROHS3 compliant while NJM79L18A is non-compliant; (5) Operating temperature range—NJM79L18A operates -40°C to 85°C while MC79L18ACPG operates 0°C to 125°C.

Q: Are the packages physically identical?

A: Both parts use the TO-92-3 (TO-226-3) through-hole package. The MC79L18ACPG is specified as "Long Body" variant, which may have slightly different physical dimensions. Verify mechanical compatibility with your PCB layout and component spacing before production implementation.

Q: What should I consider when selecting between these parts?

A: Selection depends on your circuit requirements: (1) If your design requires -40V maximum input voltage, the NJM79L18A specification is necessary; (2) If PSRR performance above 48dB is critical, the NJM79L18A provides superior performance; (3) If RoHS3 compliance is required, the MC79L18ACPG is the only option; (4) If long-term component availability is important, the MC79L18ACPG as an active product is preferable to the obsolete NJM79L18A.

Q: Are there any thermal or quiescent current differences I should know about?

A: The NJM79L18A specifies a quiescent current of 6.5mA. The MC79L18ACPG quiescent current is not specified in the provided data. The NJM79L18A specifies a maximum dropout voltage parameter that is not provided for the MC79L18ACPG. Obtain detailed datasheets from both manufacturers to compare thermal performance and quiescent current characteristics for your specific application.