MMBT3906T Equivalent & Substitute Parts

Part Overview

The MMBT3906T is a surface mount PNP bipolar junction transistor manufactured by onsemi, rated for 40 V collector-emitter breakdown voltage and 200 mA maximum collector current. This device is classified as obsolete, though 4200 pieces remain in stock as new original inventory. The MMBT3906T is packaged in SC-89-3 (SOT-490) configuration and is suitable for general-purpose switching and amplification applications requiring PNP polarity in compact surface mount form factors.

Due to the obsolete product status, equivalent and substitute parts are necessary to ensure design continuity, long-term availability, and supply chain reliability for new production runs and ongoing support of existing designs.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP	—
Voltage - Collector Emitter Breakdown (Max)	40	V
Current - Collector (Ic) (Max)	200	mA
Vce Saturation (Max) @ Ib, Ic	400 mV @ 5 mA, 50 mA	—
DC Current Gain (hFE) (Min) @ Ic, Vce	100 @ 10 mA, 1 V	—
Power - Max	250	mW
Frequency - Transition	250	MHz
Operating Temperature (Max)	150	°C (TJ)
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the MMBT3906T is determined by strict equivalence across the following critical parameters:

Primary Substitution Criteria:

Transistor polarity: PNP
Voltage rating: 40 V collector-emitter breakdown (minimum)
Current rating: 200 mA collector current (minimum)
DC current gain (hFE): 100 @ 10 mA, 1 V (minimum)
Transition frequency: 250 MHz (minimum)
Power dissipation: 250 mW (minimum)
Compliance: ROHS3 compliant, MSL 1

Secondary Considerations:

Package form factor (surface mount variants acceptable)
Operating temperature range
Product status (active preferred for long-term availability)

Substitute parts are grouped into two categories:

Category A - Direct Equivalents (Same Base Product): Parts sharing the MMBT3906 base product number with identical electrical specifications but different package configurations or manufacturer variants. These include MMBT3906LT1G (SOT-23-3), MMBT3906TT1G (SC-75, SOT-416), and MMBT3906T RSG (SOT-523).

Category B - Functional Equivalents (Different Manufacturer): The 2PA1774QM,315 from Nexperia USA Inc. meets the core voltage and polarity requirements but operates at reduced maximum collector current (100 mA versus 200 mA) and transition frequency (100 MHz versus 250 MHz). This part is suitable only for applications not requiring the full 200 mA current capability or 250 MHz bandwidth.

Parameter Comparison

Parameter	MMBT3906T (Main)	MMBT3906LT1G	MMBT3906TT1G	MMBT3906T RSG	2PA1774QM,315
Manufacturer	onsemi	onsemi	onsemi	Taiwan Semiconductor Corporation	Nexperia USA Inc.
Transistor Type	PNP	PNP	PNP	PNP	PNP
Voltage - Collector Emitter Breakdown (Max)	40 V	40 V	40 V	40 V	40 V
Current - Collector (Ic) (Max)	200 mA	200 mA	200 mA	200 mA	100 mA
Vce Saturation (Max) @ Ib, Ic	400 mV @ 5 mA, 50 mA	400 mV @ 5 mA, 50 mA	400 mV @ 5 mA, 50 mA	400 mV @ 5 mA, 50 mA	200 mV @ 5 mA, 50 mA
DC Current Gain (hFE) (Min) @ Ic, Vce	100 @ 10 mA, 1 V	100 @ 10 mA, 1 V	100 @ 10 mA, 1 V	100 @ 10 mA, 1 V	120 @ 1 mA, 6 V
Power - Max	250 mW	300 mW	200 mW	150 mW	430 mW
Frequency - Transition	250 MHz	250 MHz	250 MHz	250 MHz	100 MHz
Operating Temperature (Max)	150°C (TJ)	150°C (TJ)	150°C (TJ)	150°C (TJ)	150°C (TJ)
Package / Case	SC-89, SOT-490	TO-236-3, SC-59, SOT-23-3	SC-75, SOT-416	SOT-523	SC-101, SOT-883
Product Status	Obsolete	Active	Active	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
MSL	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

For Direct Replacement (Recommended):

MMBT3906LT1G, MMBT3906TT1G, and MMBT3906T RSG are preferred substitutes for the obsolete MMBT3906T. All three parts maintain identical electrical specifications (200 mA collector current, 40 V breakdown voltage, 250 MHz transition frequency, 100 hFE minimum) and are manufactured by onsemi or Taiwan Semiconductor Corporation with active product status. These parts carry ROHS3 compliance and MSL 1 rating, matching the original device.

Selection among these three should be based on package availability and PCB layout requirements:

MMBT3906LT1G (SOT-23-3) offers the widest availability (608,935 pieces in stock) and is suitable for standard surface mount assembly.
MMBT3906TT1G (SC-75, SOT-416) provides a compact alternative with 176,100 pieces available.
MMBT3906T RSG (SOT-523) is the smallest footprint option with 5,683 pieces in stock.

For Current-Limited Applications:

The 2PA1774QM,315 from Nexperia USA Inc. is suitable only for applications where collector current does not exceed 100 mA and transition frequency requirements do not exceed 100 MHz. This part is AEC-Q101 qualified for automotive applications. Use of this part in designs requiring the full 200 mA specification will result in performance degradation or device failure.

Compliance and Certification:

All substitute parts maintain ROHS3 compliance and MSL 1 rating. The 2PA1774QM,315 carries additional AEC-Q101 automotive qualification, which may be required for specific application domains but is not necessary for general-purpose switching applications.

Frequently Asked Questions (FAQ)

Q: Can MMBT3906LT1G be used as a direct replacement for MMBT3906T?

A: Yes. MMBT3906LT1G maintains identical electrical specifications (200 mA, 40 V, 250 MHz, 100 hFE) and is manufactured by onsemi with active product status. The primary difference is package configuration: SOT-23-3 (TO-236) versus SC-89-3 (SOT-490). PCB layout modifications are required to accommodate the different footprint.

Q: What is the difference between MMBT3906TT1G and MMBT3906LT1G?

A: Both parts share identical electrical specifications and onsemi manufacture. The difference is package form factor: MMBT3906TT1G uses SC-75 (SOT-416) packaging, while MMBT3906LT1G uses SOT-23-3 (TO-236) packaging. Selection depends on available PCB space and assembly equipment compatibility.

Q: Is 2PA1774QM,315 a suitable replacement for MMBT3906T?

A: 2PA1774QM,315 is not a direct replacement. While it maintains the 40 V voltage rating and PNP polarity, it operates at reduced maximum collector current (100 mA versus 200 mA) and transition frequency (100 MHz versus 250 MHz). Use this part only in applications where these reduced specifications are acceptable. The part carries AEC-Q101 automotive qualification, which may be beneficial for automotive applications.

Q: Why is MMBT3906T classified as obsolete?

A: Product status is determined by the manufacturer. Obsolete classification indicates that onsemi has discontinued active production and support for this specific part number. Substitute parts with active status provide assured long-term availability and manufacturer support.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed (MMBT3906LT1G, MMBT3906TT1G, MMBT3906T RSG, and 2PA1774QM,315) are ROHS3 compliant with MSL 1 rating, matching the original MMBT3906T specification.

Q: What is the smallest package option available?

A: MMBT3906T RSG in SOT-523 packaging provides the smallest footprint among direct electrical equivalents. This part is manufactured by Taiwan Semiconductor Corporation with 5,683 pieces in current stock.

Q: Can package changes affect circuit performance?

A: Package changes do not affect electrical performance of the transistor itself. However, different packages have different lead inductance and thermal characteristics. PCB layout must be modified to accommodate the new footprint, and thermal management considerations may differ between packages. Verify PCB design compatibility before implementation.

Q: Which substitute has the highest inventory availability?

A: MMBT3906LT1G has the highest inventory with 608,935 pieces in stock, followed by MMBT3906TT1G with 176,100 pieces. Both are suitable for immediate procurement and long-term supply assurance.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message