BD788G Equivalent & Substitute Parts

Part Overview

The BD788G is a PNP bipolar junction transistor manufactured by onsemi, rated for 60 V collector-emitter breakdown voltage and 4 A maximum collector current in a Through Hole TO-126 package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The BD788G delivers 15 W maximum power dissipation and operates across a temperature range of -65°C to 150°C (TJ).

Key Parameters

Parameter	BD788G Value
Transistor Type	PNP
Voltage - Collector Emitter Breakdown (Max)	60 V
Current - Collector (Ic) (Max)	4 A
Power - Max	15 W
Frequency - Transition	50 MHz
Mounting Type	Through Hole
Package / Case	TO-225AA, TO-126-3
Operating Temperature	-65°C ~ 150°C (TJ)
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution of the BD788G is determined by the following critical parameters: transistor type (PNP), mounting configuration (Through Hole), package compatibility (TO-126 or equivalent), and electrical ratings including voltage, current, and power dissipation capabilities.

The substitute parts listed below maintain PNP polarity and Through Hole mounting. Substitution validity depends on whether the application circuit can operate within the electrical constraints of each alternative part. The key parameters governing substitution are:

Transistor Type: PNP (required match)
Mounting Type: Through Hole (required match)
Voltage - Collector Emitter Breakdown: Must equal or exceed circuit maximum voltage
Current - Collector (Max): Must equal or exceed circuit maximum current
Power - Max: Must equal or exceed circuit power dissipation
Frequency - Transition: Must support circuit operating frequency
Operating Temperature Range: Must encompass application temperature requirements

Parameter Comparison

Parameter	BD788G	MJE172G	BD438
Manufacturer	onsemi	onsemi	STMicroelectronics
Transistor Type	PNP	PNP	PNP
Voltage - Collector Emitter Breakdown (Max)	60 V	80 V	45 V
Current - Collector (Ic) (Max)	4 A	3 A	4 A
Power - Max	15 W	1.5 W	36 W
Frequency - Transition	50 MHz	50 MHz	3 MHz
Mounting Type	Through Hole	Through Hole	Through Hole
Package / Case	TO-225AA, TO-126-3	TO-225AA, TO-126-3	TO-225AA, TO-126-3
Operating Temperature	-65°C ~ 150°C (TJ)	-65°C ~ 150°C (TJ)	-65°C ~ 150°C (TJ)
Product Status	Obsolete	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

MJE172G (onsemi): This substitute is an active product with identical package configuration (TO-126-3) and matching frequency-transition rating (50 MHz). The MJE172G provides higher voltage rating (80 V versus 60 V), supporting applications with elevated voltage margins. However, maximum collector current is reduced to 3 A and maximum power dissipation is 1.5 W, making this substitute suitable only for circuits requiring less than 3 A collector current and lower power dissipation than the original BD788G specification.

BD438 (STMicroelectronics): This substitute is an active product with identical package configuration (TO-126-3) and matching collector current rating (4 A). The BD438 provides significantly higher power dissipation capability (36 W versus 15 W). However, the maximum voltage rating is reduced to 45 V and the frequency-transition rating is substantially lower at 3 MHz. This substitute is applicable only to circuits operating below 45 V and not requiring the 50 MHz frequency performance of the original device.

Both substitute parts maintain ROHS3 compliance and Through Hole mounting, ensuring mechanical and regulatory compatibility with existing designs. Selection between substitutes depends on whether the application circuit can operate within the reduced electrical ratings of each alternative.

Frequently Asked Questions (FAQ)

Q: Can MJE172G replace BD788G in all applications?

A: No. The MJE172G is suitable only for applications where collector current does not exceed 3 A and power dissipation does not exceed 1.5 W. Applications requiring the full 4 A current or 15 W power capability of the BD788G cannot use MJE172G as a direct substitute.

Q: Can BD438 replace BD788G in all applications?

A: No. The BD438 is suitable only for applications where collector-emitter voltage does not exceed 45 V and operating frequency does not exceed 3 MHz. Applications requiring 60 V voltage rating or 50 MHz frequency performance cannot use BD438 as a direct substitute.

Q: Are the package dimensions identical between BD788G, MJE172G, and BD438?

A: All three devices use Through Hole mounting with TO-225AA and TO-126-3 package designations, ensuring mechanical compatibility in PCB layouts designed for the BD788G.

Q: What is the impact of the BD788G obsolescence status?

A: The BD788G is classified as obsolete, meaning onsemi no longer manufactures this device. MJE172G and BD438 are both active products with ongoing manufacturing support and availability.

Q: Do all three devices meet RoHS3 compliance requirements?

A: Yes. BD788G, MJE172G, and BD438 are all ROHS3 compliant, meeting environmental and regulatory requirements for electronic component use.

Q: How do operating temperature ranges compare?

A: All three devices operate across the identical temperature range of -65°C to 150°C (TJ), ensuring thermal compatibility in applications with specified temperature requirements.

Q: What is the primary difference in DC current gain between these devices?

A: DC current gain specifications differ across the three devices. BD788G specifies 40 @ 200mA, 3V; MJE172G specifies 50 @ 100mA, 1V; and BD438 specifies 30 @ 10mA, 5V. These differences reflect different measurement conditions and device design characteristics.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message