MMBT4354 Equivalent & Substitute Parts

Part Overview

The MMBT4354 is a surface mount PNP bipolar junction transistor manufactured by onsemi, housed in a SOT-23-3 package. This device is rated for 60 V collector-emitter breakdown voltage and 800 mA maximum collector current, with a maximum power dissipation of 350 mW. The MMBT4354 is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility within the electrical and mechanical constraints of the application.

Key Parameters

Parameter	MMBT4354	Unit
Transistor Type	PNP	—
Voltage - Collector Emitter Breakdown (Max)	60	V
Current - Collector (Ic) (Max)	800	mA
Power - Max	350	mW
Vce Saturation (Max) @ Ib, Ic	500mV @ 50mA, 500mA	V
DC Current Gain (hFE) (Min) @ Ic, Vce	50 @ 10mA, 5V	—
Operating Temperature	-55 to 150	°C
Package / Case	SOT-23-3 (TO-236)	—
Mounting Type	Surface Mount	—
Product Status	Obsolete	—

Substitute Part Grouping Explanation

Substitute parts for the MMBT4354 are grouped based on the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Transistor Type: PNP (required)
Package / Case: SOT-23-3 (TO-236) (required for mechanical compatibility)
Mounting Type: Surface Mount (required)
Operating Temperature Range: -55°C to 150°C (required)
Voltage - Collector Emitter Breakdown: ≥60 V (minimum requirement)
Current - Collector (Ic) (Max): ≥800 mA (minimum requirement for full current handling)
Power - Max: ≥350 mW (minimum requirement)

Substitution Groups:

Group 1: Direct Current Capability Substitutes (Ic ≥ 800 mA) Parts meeting or exceeding the full 800 mA collector current specification with 60 V or higher breakdown voltage. These provide direct functional replacement without derating.

Group 2: Reduced Current Substitutes (Ic < 800 mA) Parts with collector current ratings below 800 mA but with compatible voltage ratings and package. These are suitable for applications where the actual operating current does not approach the 800 mA maximum.

Group 3: Automotive Grade Alternatives Parts with AEC-Q101 qualification and automotive grade designation, suitable for applications requiring automotive-grade reliability.

Parameter Comparison

Part Number	Manufacturer	Ic (Max) mA	Vce Breakdown (Max) V	Power (Max) mW	Vce Sat (Max) @ Ib, Ic	hFE (Min) @ Ic, Vce	Frequency - Transition	Product Status	RoHS Status
MMBT4354	onsemi	800	60	350	500mV @ 50mA, 500mA	50 @ 10mA, 5V	—	Obsolete	—
MMBT2907ALT1G	onsemi	600	60	300	1.6V @ 50mA, 500mA	100 @ 150mA, 10V	200MHz	Active	ROHS3 Compliant
MMBT2907ALT3G	onsemi	600	60	300	1.6V @ 50mA, 500mA	100 @ 150mA, 10V	200MHz	Active	ROHS3 Compliant
MMBT4403LT1G	onsemi	600	40	300	750mV @ 50mA, 500mA	100 @ 150mA, 2V	200MHz	Active	ROHS3 Compliant
MMBT4403LT3G	onsemi	600	40	300	750mV @ 50mA, 500mA	100 @ 150mA, 2V	200MHz	Active	ROHS3 Compliant
BC856ALT1G	onsemi	100	65	300	650mV @ 5mA, 100mA	125 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant
BC856BLT1G	onsemi	100	65	300	650mV @ 5mA, 100mA	220 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant
BC856BLT3G	onsemi	100	65	300	650mV @ 5mA, 100mA	220 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant
SBC856ALT1G	onsemi	100	65	300	650mV @ 5mA, 100mA	125 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant
SBC856BLT1G	onsemi	100	65	300	650mV @ 5mA, 100mA	220 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant
SBC856BLT3G	onsemi	100	65	300	650mV @ 5mA, 100mA	220 @ 2mA, 5V	100MHz	Active	ROHS3 Compliant

Engineering Selection Recommendations

For Applications Requiring Full 800 mA Current Capability:

The MMBT2907ALT1G and MMBT2907ALT3G are the only active substitutes that approach the collector current specification of the MMBT4354, rated at 600 mA. These parts share the same 60 V breakdown voltage rating and are available in active product status with ROHS3 compliance. The MMBT2907 series offers higher transition frequency (200 MHz) compared to the obsolete MMBT4354. Both packaging variants (Cut Tape and Tape & Reel) are available with substantial inventory levels.

For Applications with Reduced Current Requirements (≤600 mA):

The MMBT2907ALT1G and MMBT2907ALT3G remain the primary recommendation, as they maintain the 60 V voltage rating and provide active product status with full compliance documentation.

For Applications with Voltage Constraints (≤40 V):

The MMBT4403LT1G and MMBT4403LT3G are suitable alternatives when the application operates at 40 V or below. These parts are rated for 600 mA collector current and are available in active product status with ROHS3 compliance.

For Low-Current Applications (≤100 mA):

The BC856 and SBC856 series (ALT1G, BLT1G, BLT3G variants) are suitable for applications requiring only 100 mA or less. The BC856 series is available in standard commercial grade, while the SBC856 series provides automotive-grade qualification (AEC-Q101) for applications requiring automotive reliability standards. All variants are active products with ROHS3 compliance and higher voltage ratings (65 V).

Compliance and Availability:

All recommended substitute parts are manufactured by onsemi, maintain SOT-23-3 package compatibility, and are classified as active products. All substitutes carry ROHS3 compliance. Automotive-grade alternatives (SBC856 series) are available for applications requiring AEC-Q101 qualification.

Frequently Asked Questions (FAQ)

Q: Can the MMBT2907ALT1G directly replace the MMBT4354 in all applications?

A: The MMBT2907ALT1G is compatible with applications where the actual operating collector current does not exceed 600 mA. The MMBT4354 is rated for 800 mA maximum, so applications operating near or above 600 mA require circuit analysis to confirm the MMBT2907 series is suitable. Both parts share the same 60 V breakdown voltage and SOT-23-3 package, ensuring mechanical and voltage compatibility.

Q: What is the difference between BC856ALT1G, BC856BLT1G, and BC856BLT3G?

A: These variants differ in DC current gain (hFE) specification and packaging format. BC856ALT1G specifies hFE minimum of 125 at 2 mA, 5V. BC856BLT1G and BC856BLT3G specify hFE minimum of 220 at the same conditions. The "ALT1" designation indicates Cut Tape & Digi-Reel packaging, while "BLT1" and "BLT3" indicate Tape & Reel packaging. All three are electrically equivalent in voltage and current ratings.

Q: Why are the BC856 and SBC856 series rated for only 100 mA when the MMBT4354 is rated for 800 mA?

A: The BC856 and SBC856 series are designed for low-signal applications requiring lower collector current. These parts are suitable only for applications where the actual operating current does not exceed 100 mA. For applications requiring higher current capability, the MMBT2907 series is the appropriate substitute.

Q: What is the significance of the "S" prefix in SBC856?

A: The "S" prefix indicates automotive-grade qualification to AEC-Q101 standard. SBC856 parts are suitable for automotive applications requiring enhanced reliability and qualification documentation. Commercial-grade BC856 parts are suitable for general industrial and consumer applications.

Q: Are all substitute parts ROHS3 compliant?

A: All recommended substitute parts carry ROHS3 compliance certification. The obsolete MMBT4354 does not have ROHS3 compliance documentation provided in the specifications.

Q: Can I use MMBT4403LT1G in a 60 V application?

A: No. The MMBT4403LT1G is rated for 40 V maximum collector-emitter breakdown voltage. Using this part in a 60 V application exceeds its voltage rating and will result in device failure. The MMBT2907 series must be used for 60 V applications.

Q: What is the difference between Cut Tape and Tape & Reel packaging?

A: Both are surface mount packaging formats suitable for automated assembly. Cut Tape (CT) & Digi-Reel packaging is supplied in smaller quantities on cut tape. Tape & Reel (TR) packaging is supplied in continuous reel format for high-volume production. Electrical and mechanical specifications are identical; the difference is in supply format and handling.

Q: Is the MMBT4354 still available for purchase?

A: The MMBT4354 is classified as obsolete. While inventory may exist from distributors, no new production is available from onsemi. Active substitute parts must be used for new designs and ongoing production.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message