MPSA18RLRAG Equivalent & Substitute Parts

Part Overview

The MPSA18RLRAG is an NPN bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. This device features a 45 V collector-emitter breakdown voltage, 200 mA maximum collector current, and 625 mW power dissipation in a through-hole TO-92 package. The MPSA18RLRAG is classified as obsolete, necessitating identification of equivalent and substitute components for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility while accommodating differences in electrical ratings and package configurations.

Substiute Parts

MPSA18RLRAG

onsemiIn Stock: 7887MPSA18RLRAG Datasheet

Current PartRFQ

2N4401BU

onsemiIn Stock: 99862N4401BU Datasheet

DirectRFQ

MMBT5089LT1G

onsemiIn Stock: 35446MMBT5089LT1G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MPSA18RLRAG are categorized based on compatibility with the following critical parameters: transistor type (NPN), operating temperature range (-55°C ~ 150°C), and package form factor. Substitution logic is determined by the allowed electrical specifications:

Direct Substitutes maintain the same package type (through-hole TO-92) and support equivalent or superior electrical ratings within the specified operating temperature range.

Similar Substitutes provide functional equivalence through different package technologies (surface mount) while maintaining NPN polarity and compatible temperature specifications. These substitutes are suitable for designs where package conversion is feasible.

The following parameters establish substitution boundaries:

• Transistor polarity: NPN (mandatory)
• Operating temperature: -55°C ~ 150°C (mandatory)
• Collector-emitter breakdown voltage: minimum 40 V (for direct substitutes)
• Maximum collector current: minimum 200 mA (for direct substitutes)
• Power dissipation: 625 mW (standard for through-hole packages)

Parameter Comparison

Engineering Selection Recommendations

2N4401BU is the primary direct substitute for the MPSA18RLRAG. Both devices share identical through-hole TO-92 package configurations, identical operating temperature ranges (-55°C ~ 150°C), and equivalent power dissipation (625 mW). The 2N4401BU maintains NPN polarity and exceeds the collector-emitter breakdown voltage requirement (40 V versus 45 V specification). The 2N4401BU is classified as active product status with RoHS3 compliance, ensuring long-term availability and regulatory conformance. The 2N4401BU supports higher maximum collector current (600 mA) and transition frequency (250 MHz) compared to the MPSA18RLRAG, providing design margin for current and frequency-dependent applications.

MMBT5089LT1G is a similar substitute suitable for applications where surface-mount technology is acceptable. This device maintains NPN polarity and identical operating temperature range (-55°C ~ 150°C). The MMBT5089LT1G is classified as active product status with RoHS3 compliance. However, the MMBT5089LT1G operates at reduced voltage (25 V maximum) and current (50 mA maximum) ratings compared to the MPSA18RLRAG. The MMBT5089LT1G is appropriate for low-power signal-level applications and requires circuit redesign for applications demanding the full 45 V or 200 mA specifications of the original device.

Frequently Asked Questions (FAQ)

Q: Can the 2N4401BU directly replace the MPSA18RLRAG in existing through-hole PCB designs?

A: Yes. Both devices use identical TO-92-3 (TO-226) through-hole package configurations with matching pin assignments. No PCB modifications are required. The 2N4401BU operates within the same temperature range and provides equivalent or superior electrical performance.

Q: What are the key electrical differences between the MPSA18RLRAG and 2N4401BU?

A: The 2N4401BU has a 40 V collector-emitter breakdown voltage (versus 45 V for the MPSA18RLRAG), supporting higher maximum collector current (600 mA versus 200 mA) and higher transition frequency (250 MHz versus 160 MHz). The 2N4401BU exhibits higher saturation voltage (750 mV @ 50mA, 500mA versus 300 mV @ 5mA, 50mA), which may affect switching speed in saturation-mode applications.

Q: Is the MMBT5089LT1G suitable as a substitute for the MPSA18RLRAG?

A: The MMBT5089LT1G is a similar substitute only for applications operating below 25 V and 50 mA. This device is not suitable for applications requiring the full 45 V or 200 mA specifications of the MPSA18RLRAG. The MMBT5089LT1G requires surface-mount assembly capability and circuit redesign to accommodate reduced electrical ratings.

Q: What is the impact of package type differences when substituting the MMBT5089LT1G?

A: The MMBT5089LT1G uses SOT-23-3 surface-mount packaging, requiring different PCB layout, assembly processes, and test procedures compared to the through-hole TO-92 package of the MPSA18RLRAG. Surface-mount assembly is not compatible with through-hole PCB designs without significant redesign.

Q: Are all substitute parts RoHS compliant?

A: The 2N4401BU and MMBT5089LT1G are both RoHS3 compliant. The MPSA18RLRAG does not specify RoHS status. All three devices are REACH unaffected and classified under ECCN EAR99.

Q: What is the inventory status of substitute parts?

A: The 2N4401BU has 9,900 pieces in stock (active product status). The MMBT5089LT1G has 35,400 pieces in stock (active product status). The MPSA18RLRAG has 7,797 pieces in stock but is classified as obsolete.