ZTX549 Equivalent & Substitute Parts

Part Overview

The ZTX549 is an active PNP bipolar junction transistor manufactured by Diodes Incorporated, designed for general-purpose switching and amplification applications. The device is rated for 30 V collector-emitter breakdown voltage and 1 A maximum collector current, with a maximum power dissipation of 1 W. The ZTX549 is packaged in an E-Line (TO-92 compatible) through-hole configuration and is RoHS3 compliant with unlimited moisture sensitivity rating.

Equivalent and substitute parts are identified when alternative devices meet or exceed the electrical and mechanical specifications of the primary part, enabling procurement flexibility, inventory management, and design continuity across manufacturing cycles.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP	—
Voltage - Collector Emitter Breakdown (Max)	30	V
Current - Collector (Ic) (Max)	1	A
Power - Max	1	W
Frequency - Transition	100	MHz
DC Current Gain (hFE) (Min)	100	—
Operating Temperature Range	-55 to 200	°C
Mounting Type	Through Hole	—
Package / Case	E-Line-3 (TO-92 compatible)	—

Substitute Part Grouping Explanation

Substitution of the ZTX549 is determined by the following critical parameters:

Electrical Compatibility Requirements:

Transistor type must be PNP
Collector-emitter breakdown voltage must be greater than or equal to 30 V
Maximum collector current must be greater than or equal to 1 A
Maximum power dissipation must be greater than or equal to 1 W
DC current gain (hFE) must be greater than or equal to 100

Mechanical Compatibility Requirements:

Mounting type must be through-hole
Package must be physically compatible with TO-92 or equivalent three-lead configurations

Compliance Requirements:

Product status must be active
RoHS compliance status must be acceptable for the application

The PN2907BU from Fairchild Semiconductor meets these substitution criteria with electrical ratings that exceed the ZTX549 minimum specifications in voltage (40 V vs. 30 V) and maintains equivalent current gain characteristics. Both devices are active products with appropriate compliance certifications.

Parameter Comparison

Parameter	ZTX549 (Diodes Inc.)	PN2907BU (Fairchild)	Compatibility
Transistor Type	PNP	PNP	Match
Voltage - Collector Emitter Breakdown (Max)	30 V	40 V	Substitute exceeds
Current - Collector (Ic) (Max)	1 A	800 mA	Substitute below primary
Power - Max	1 W	625 mW	Substitute below primary
DC Current Gain (hFE) (Min)	100	100	Match
Operating Temperature Range	-55 to 200°C	-55 to 150°C	Primary exceeds
Mounting Type	Through Hole	Through Hole	Match
Package / Case	E-Line-3 (TO-92 compatible)	TO-92-3 (TO-226AA)	Physically compatible
Product Status	Active	Active	Match

Engineering Selection Recommendations

ZTX549 Selection Criteria: The ZTX549 is the primary choice for applications requiring the full 1 A collector current rating, 1 W power dissipation capability, and extended operating temperature range to 200°C. This device is suitable for high-temperature environments and applications with demanding current requirements.

PN2907BU Selection Criteria: The PN2907BU is suitable as a substitute in applications where the collector current requirement does not exceed 800 mA and power dissipation remains below 625 mW. The PN2907BU provides higher collector-emitter breakdown voltage (40 V) and is appropriate for circuits operating within the -55°C to 150°C temperature range. Both devices maintain active product status and appropriate compliance certifications for industrial and commercial applications.

Substitution Limitations: The PN2907BU cannot be used in designs requiring the full 1 A current capacity or 1 W power dissipation of the ZTX549. Applications with operating temperatures above 150°C require the ZTX549.

Frequently Asked Questions (FAQ)

Q: Can the PN2907BU directly replace the ZTX549 in all applications?

A: No. The PN2907BU has reduced maximum collector current (800 mA vs. 1 A) and power dissipation (625 mW vs. 1 W). Substitution is valid only when circuit design operates within these lower limits. The PN2907BU also has a lower maximum operating temperature (150°C vs. 200°C).

Q: Are the packages physically interchangeable?

A: Yes. Both the ZTX549 (E-Line-3, TO-92 compatible) and PN2907BU (TO-92-3) use three-lead through-hole packages with compatible pin configurations and spacing, allowing direct physical substitution on printed circuit boards.

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

A: The PN2907BU provides higher collector-emitter breakdown voltage (40 V vs. 30 V), which offers additional design margin in voltage-limited applications. However, the ZTX549 provides higher current capacity (1 A vs. 800 mA) and power handling (1 W vs. 625 mW). Both devices have equivalent DC current gain specifications (100 minimum).

Q: Are both parts RoHS compliant?

A: The ZTX549 is explicitly RoHS3 compliant. The PN2907BU compliance status is not specified in the provided data. Compliance verification with the PN2907BU manufacturer is required for applications with RoHS requirements.

Q: Which part should be selected for high-temperature applications?

A: The ZTX549 is required for applications operating above 150°C, as it supports temperatures to 200°C. The PN2907BU is limited to 150°C maximum junction temperature.

Q: Can the ZTX549 be used as a substitute for the PN2907BU?

A: Yes. The ZTX549 exceeds all electrical specifications of the PN2907BU and is a direct upgrade substitute, providing higher current capacity, power dissipation, and operating temperature range.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message