2N3635UB Equivalent & Substitute Parts

Part Overview

The 2N3635UB is a PNP bipolar junction transistor manufactured by Microchip Technology, designed for surface mount applications in 3-SMD, No Lead packaging. This component operates at maximum collector current of 1 A with a collector-emitter breakdown voltage of 140 V and maximum power dissipation of 1.5 W. The 2N3635UB is discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives for ongoing design requirements and production needs.

Substiute Parts

2N3635UB

Microchip TechnologyIn Stock: 10082N3635UB Datasheet

Current PartRFQ

FZT755TA

Diodes IncorporatedIn Stock: 35119FZT755TA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N3635UB is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Transistor polarity must be PNP
• Maximum collector current must equal or exceed 1 A
• Collector-emitter breakdown voltage must equal or exceed 140 V
• Maximum power dissipation must equal or exceed 1.5 W
• DC current gain characteristics must support circuit design requirements

Mechanical Compatibility Criteria:

• Surface mount mounting type
• Package form factor compatibility with PCB layout constraints

The FZT755TA meets these substitution criteria with electrical ratings that equal or exceed the 2N3635UB specifications while maintaining surface mount compatibility.

Parameter Comparison

Engineering Selection Recommendations

The FZT755TA from Diodes Incorporated serves as a functional substitute for the discontinued 2N3635UB. Selection of the FZT755TA is based on the following engineering factors:

Electrical Performance: The FZT755TA meets or exceeds all critical electrical specifications of the 2N3635UB, including collector current (1 A), collector-emitter breakdown voltage (150 V versus 140 V), and power dissipation (2 W versus 1.5 W). The lower saturation voltage and leakage current of the FZT755TA represent performance improvements over the original specification.

Product Availability: The FZT755TA is actively manufactured and maintained in production inventory (35,100 units in stock), whereas the 2N3635UB is discontinued. This availability ensures supply chain continuity for new designs and production requirements.

Compliance Status: The FZT755TA is ROHS3 compliant, whereas the 2N3635UB is RoHS non-compliant. Organizations subject to RoHS regulations must implement the FZT755TA for regulatory compliance.

Package Consideration: The FZT755TA utilizes SOT-223-3 packaging, which differs from the 3-SMD, No Lead package of the 2N3635UB. PCB layout modifications are required to accommodate the different package form factor.

Operating Temperature Range: The 2N3635UB supports a wider operating temperature range (-65°C to 200°C) compared to the FZT755TA (-55°C to 150°C). Applications requiring operation below -55°C or above 150°C must evaluate alternative solutions.

Frequently Asked Questions (FAQ)

Q: Can the FZT755TA directly replace the 2N3635UB without circuit modifications?

A: The FZT755TA is electrically compatible with the 2N3635UB for PNP transistor applications requiring 1 A collector current and 140 V breakdown voltage. However, the different package form factor (SOT-223-3 versus 3-SMD, No Lead) requires PCB layout modifications. Verify that the SOT-223-3 package footprint is compatible with your PCB design before implementation.

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

A: Both transistors are PNP types with identical maximum collector current (1 A). The FZT755TA provides higher collector-emitter breakdown voltage (150 V versus 140 V), higher power dissipation capability (2 W versus 1.5 W), lower saturation voltage (500mV versus 600mV), and lower leakage current (100nA versus 10µA). These differences represent performance improvements in the FZT755TA.

Q: Is the FZT755TA suitable for applications requiring extended temperature operation?

A: The FZT755TA operates from -55°C to 150°C junction temperature, which is narrower than the 2N3635UB range of -65°C to 200°C. Applications requiring operation below -55°C or above 150°C must evaluate alternative PNP transistor solutions that support the required temperature range.

Q: What compliance advantages does the FZT755TA offer?

A: The FZT755TA is ROHS3 compliant, whereas the 2N3635UB is RoHS non-compliant. Organizations operating under RoHS regulations must implement the FZT755TA to meet regulatory requirements. Both parts maintain identical Moisture Sensitivity Level (MSL 1) and REACH Unaffected status.

Q: Are there inventory considerations when transitioning from 2N3635UB to FZT755TA?

A: The 2N3635UB is discontinued at DiGi Electronics with 966 units in stock. The FZT755TA is actively produced with 35,100 units in stock, providing superior supply chain availability for ongoing production and future design requirements.

Q: How do the DC current gain characteristics compare?

A: The 2N3635UB specifies minimum DC current gain of 100 at 50mA collector current and 10V collector-emitter voltage. The FZT755TA specifies minimum DC current gain of 50 at 500mA collector current and 5V collector-emitter voltage. These specifications are measured at different operating points; circuit design must account for the specific gain characteristics at intended operating conditions.