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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi 2SC3787S

Name: 2SC3787S
Brand: onsemi
SKU: 2SC3787S
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SC3787S

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: 2SC3787S.pdf

Description:: TRANS NPN 160V 0.14A TO-126ML

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SC3787S from SANYO is an NPN epitaxial planar silicon transistor rated for 160V V_CBO, 140mA I_C, and 1.3W P_C at T_C=25°C, optimized for switching applications including predrivers in 100W power amplifiers. It features FBET process technology, excellent h_FE linearity, low C_ob (0.4pF), and TO-126ML plastic-encapsulated heat sink package.

For engineers reviewing the 2SC3787S datasheet, pinout, applications, or equivalent options, key selection criteria include its 160V breakdown rating, 140mA continuous collector current, 1.3W power dissipation at case temperature, FBET process benefits for linearity, and TO-126ML thermal package suitability for high-density mounting in audio and industrial switching designs.

Technical Context

The 2SC3787S operates as a medium-power NPN switching transistor with V_CBO = −160V, V_CEO = −140V, and V_EBO = −5V. Its h_FE is specified at 100–400 (measured at V_CE = −5V, I_C = −10mA), and f_T reaches 150MHz under V_CE = −10V, I_C = −10mA conditions.

Switching performance is characterized by t_on = 0.1µs, t_stg = 0.5µs, and t_off = 0.1µs using standard test circuits. The device uses SANYO's FBET (Flat Base Epitaxial Transistor) process to achieve tight h_FE linearity and reduced output capacitance (C_ob = 0.4pF).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CBO	−160V - Maximum reverse-biased collector-base voltage before breakdown; supports high-voltage switching stages.
I_C	−140mA - Continuous collector current rating; suitable for driver-stage loads in 100W amplifier designs.
P_C @ T_C=25°C	1.3W - Power dissipation capability with heatsink; enables compact thermal design in TO-126ML package.
h_FE	100–400 - DC current gain range at V_CE=−5V, I_C=−10mA; ensures predictable biasing in linear and switching modes.
f_T	150MHz - Transition frequency at V_CE=−10V, I_C=−10mA; supports high-speed switching up to audio RF bands.
C_ob	0.4pF - Output capacitance at V_CB=−10V, f=1MHz; minimizes Miller effect and improves switching efficiency.

Pinout & Package

SANYO TO-126ML plastic-encapsulated package with integral heat sink tab; thermally efficient for surface-mount-compatible through-hole assembly. Pin 1 = Emitter, Pin 2 = Collector (connected to heat sink tab), Pin 3 = Base.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current exit terminal; electrically isolated from heat sink tab; referenced for base-emitter bias control.
2	Collector	Main current input terminal; internally bonded to metal heat sink tab; requires electrical isolation from PCB ground plane.
3	Base	Control electrode; accepts low-current drive to modulate collector-emitter conduction; sensitive to ESD due to thin base region.

Key Features

Feature	Design Value
FBET process technology	Enables precise base doping profile for improved h_FE linearity and reduced base resistance across operating range.
Low C_ob (0.4pF)	Reduces capacitive loading on driving stage and suppresses high-frequency oscillation in switching nodes.
TO-126ML heat sink integration	Eliminates need for separate mounting hardware; allows direct PCB thermal coupling via tab while maintaining electrical isolation.
High V_CBO (−160V)	Supports operation in high-voltage supply rails common in discrete audio amplifier output stages and industrial SMPS drivers.

Applications

Predriver Stage in 100W Audio Amplifier	High-Voltage Switching Regulator Driver
Use Scenario: Driving complementary output transistors in Class-AB audio power stages delivering up to 100W into 4Ω or 8Ω loads. IC Role / Device Role / Timing Role: NPN switch providing current gain and voltage swing to turn on high-power output devices rapidly and symmetrically. Use Value: FBET process ensures consistent h_FE across signal swing, reducing crossover distortion; low C_ob prevents phase shift at high frequencies.	Use Scenario: Controlling gate of high-side MOSFET or IGBT in flyback or forward converter primary-side switching circuits with >100V bus. IC Role / Device Role / Timing Role: Medium-power NPN switch translating PWM controller output to higher-current drive for power semiconductor gates. Use Value: 160V V_CBO withstands reflected voltage spikes; 1.3W dissipation handles peak gate charge currents without derating.
Industrial Relay/Contactor Driver	Discrete Logic-Level Signal Inverter
Use Scenario: Directly energizing 24V or 48V industrial relay coils or contactor solenoids requiring ≥100mA steady-state current. IC Role / Device Role / Timing Role: High-gain NPN switch converting microcontroller GPIO output into coil-driving current with minimal base drive burden. Use Value: h_FE ≥100 at 10mA base current ensures full saturation with logic-level inputs; TO-126ML tab provides mechanical robustness in vibration-prone environments.	Use Scenario: Level-shifting and inverting TTL/CMOS signals in legacy industrial control panels where discrete transistor logic remains cost-effective. IC Role / Device Role / Timing Role: Fast-switching NPN inverter stage with sub-μs propagation delay and rail-to-rail output swing. Use Value: t_on/t_off ≤0.1µs enables clean digital transitions up to ~3MHz; low C_ob prevents signal coupling between adjacent channels.

Predriver Stage in 100W Audio Amplifier

High-Voltage Switching Regulator Driver

Use Scenario: Driving complementary output transistors in Class-AB audio power stages delivering up to 100W into 4Ω or 8Ω loads.

IC Role / Device Role / Timing Role: NPN switch providing current gain and voltage swing to turn on high-power output devices rapidly and symmetrically.

Use Value: FBET process ensures consistent h_FE across signal swing, reducing crossover distortion; low C_ob prevents phase shift at high frequencies.

Use Scenario: Controlling gate of high-side MOSFET or IGBT in flyback or forward converter primary-side switching circuits with >100V bus.

IC Role / Device Role / Timing Role: Medium-power NPN switch translating PWM controller output to higher-current drive for power semiconductor gates.

Use Value: 160V V_CBO withstands reflected voltage spikes; 1.3W dissipation handles peak gate charge currents without derating.

Industrial Relay/Contactor Driver

Discrete Logic-Level Signal Inverter

Use Scenario: Directly energizing 24V or 48V industrial relay coils or contactor solenoids requiring ≥100mA steady-state current.

IC Role / Device Role / Timing Role: High-gain NPN switch converting microcontroller GPIO output into coil-driving current with minimal base drive burden.

Use Value: h_FE ≥100 at 10mA base current ensures full saturation with logic-level inputs; TO-126ML tab provides mechanical robustness in vibration-prone environments.

Use Scenario: Level-shifting and inverting TTL/CMOS signals in legacy industrial control panels where discrete transistor logic remains cost-effective.

IC Role / Device Role / Timing Role: Fast-switching NPN inverter stage with sub-μs propagation delay and rail-to-rail output swing.

Use Value: t_on/t_off ≤0.1µs enables clean digital transitions up to ~3MHz; low C_ob prevents signal coupling between adjacent channels.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN switching transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SC2625	V_CBO = −120V (lower), P_C = 1.0W (lower), h_FE = 120–270 (narrower range)	Limited to ≤80W amplifier predrivers or lower-voltage SMPS; less margin for transient overvoltage	Select when board space or cost constraints outweigh need for 160V rating and 1.3W dissipation.
MJD112	V_CBO = −100V, I_C = −2A (higher), P_C = 1.5W, TO-220 package (larger footprint)	Better for high-current switching but unsuitable for space-constrained predriver layouts; no FBET linearity benefit	Choose only if higher current drive (>140mA) is required and TO-220 mounting is acceptable.

Compared with 2SC2625 and MJD112, the 2SC3787S offers superior voltage headroom and h_FE linearity in a compact TO-126ML thermal package-making it optimal for precision predriver roles where 160V standoff and low-distortion gain are critical.

Availability

2SC3787S is available at Aetrix Electronics and suitable for audio amplifier predrivers, high-voltage switching regulator drivers, industrial relay interfaces, and discrete logic inverters requiring stable component supply and long-term obsolescence management.

Supply support for 2SC3787S includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

SANYO Electric Co., Ltd. was a Japanese semiconductor manufacturer specializing in analog and power discrete devices before its acquisition by Panasonic in 2012; known for high-reliability audio and industrial transistors.

The 2SC3787S belongs to SANYO's legacy high-voltage NPN switching transistor family designed specifically for audio predriver and industrial control applications demanding stable h_FE, low capacitance, and robust thermal packaging.

FAQ

What is the maximum collector-emitter voltage rating for the 2SC3787S?

The 2SC3787S has a maximum collector-emitter voltage rating of V_CEO = −140V at T_A = 25°C. This rating defines the upper limit of reverse voltage the transistor can block between collector and emitter with the base open. Exceeding this value risks avalanche breakdown and permanent damage. Derating is required above 25°C ambient per the datasheet's thermal curves.

Is the 2SC3787S pin-compatible with the 2SA1477 PNP counterpart?

No, the 2SC3787S (NPN) and 2SA1477 (PNP) share the same TO-126ML package and pinout order (1=E, 2=C, 3=B), but their polarity and biasing requirements are opposite. While physically interchangeable on PCB, they cannot be substituted without circuit redesign-e.g., reversing supply polarity and bias network orientation. The 2SC3787S must be used only in NPN-configured circuits.

Does the 2SC3787S require a heatsink in typical predriver applications?

In typical predriver applications drawing ≤100mA average collector current, the 2SC3787S can operate without an external heatsink due to its integrated TO-126ML heat sink tab and 1.3W P_C rating at T_C = 25°C. However, sustained operation near I_C = −140mA or in ambient temperatures >50°C requires PCB copper pour or chassis mounting to maintain junction temperature below 150°C.

What does "FBET process" mean for the 2SC3787S performance?

FBET (Flat Base Epitaxial Transistor) is SANYO's proprietary fabrication process that produces a uniform, shallow base region with controlled doping. For the 2SC3787S, this yields excellent h_FE linearity across collector current-critical for low-distortion audio predriver stages-and reduces base resistance and output capacitance compared to conventional planar processes.

Can the 2SC3787S be used in linear amplifier configurations?

The 2SC3787S is characterized and qualified for switching applications, but its h_FE linearity and low C_ob make it usable in Class-A or AB linear preamplifier stages at moderate power levels. However, it lacks guaranteed SOA (Safe Operating Area) curves for linear mode, so designers must verify thermal limits and second-breakdown margins under actual bias and load conditions-not just rely on DC ratings.

2SC3787S Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 140 mA

Voltage - Collector Emitter Breakdown (Max):: 160 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 10mA, 5V

Power - Max:: 1.3 W

Frequency - Transition:: 150MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126ML

2SC3787S FAQ

1.How can I place an order for 2SC3787S through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SC3787S on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2SC3787S reliable?

The price and inventory of 2SC3787S are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SC3787S is usually 5 days.

3.What payment methods are accepted for 2SC3787S?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SC3787S transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SC3787S?

2SC3787S orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SC3787S order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2SC3787S?

For technical support, including 2SC3787S datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SC3787S requirements.

6.How does Aetrix verify that 2SC3787S is sourced from the original manufacturer or authorized distributors?

All 2SC3787S products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2SC3787S meets industry standards.

7.What is the process for return or replacement of 2SC3787S?

All 2SC3787S units undergo pre-shipment inspection (PSI). If there is an issue with 2SC3787S, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2SC3787S part is unused and in its original packaging.

Return procedure for 2SC3787S:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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