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

onsemi 2SC4645E-AN

Name: 2SC4645E-AN
Brand: onsemi
SKU: 2SC4645E-AN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SC4645E-AN

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: SC-71

Datasheet:: 2SC4645E-AN.pdf

Description:: TRANS NPN 400V 1A 3-NMP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SC4645E-AN from onsemi is an NPN triple-diffused planar silicon transistor designed for high-voltage switching and driver applications. It delivers IC = –1 A continuous collector current, V_CEO = –400 V breakdown voltage, and V_CE(sat) = –1.0 V at I_C/I_B = 10, enabling robust operation in flyback converters and horizontal deflection circuits.

For engineers reviewing the 2SC4645E-AN datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CEO ≥ 400 V, h_FE range of 40–200 at I_C = –100 mA, and validated switching times (t_on = 0.11 μs, t_f = 0.56 μs) under 150 V/200 mA test conditions.

Technical Context

This transistor operates as a high-voltage, medium-power NPN switch with epitaxial base design optimized for fast turn-on and controlled saturation. Its f_T = 70 MHz at V_CE = –10 V and I_C = –50 mA supports stable gain in RF driver stages up to UHF, while Cob = 12 pF at V_CB = –10 V ensures low capacitive loading in high-speed switching nodes.

The device uses a TO-220AB package with emitter-collector-base pinout (1=E, 2=C, 3=B), rated for T_j = 150 °C junction temperature and P_C = 1 W at T_a = 25 °C. Absolute maximum ratings confirm safe operation at V_BO = –400 V (open-base), I_C = –1 A DC, and I_CP = –2 A pulsed (10 ms).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	–400 V - Sustains 400 V collector-emitter blocking voltage before avalanche, suitable for 350 V DC bus designs.
I_C (DC)	–1 A - Supports continuous 1 A load current in linear or saturated switching modes without derating at 25 °C ambient.
V_CE(sat)	–1.0 V @ I_C/I_B = 10 - Low saturation voltage minimizes conduction loss in high-current switching paths.
h_FE	40–200 @ I_C = –100 mA, V_CE = –10 V - Wide DC current gain range enables flexible base drive design.
f_T	70 MHz @ V_CE = –10 V, I_C = –50 mA - Enables stable amplification or oscillation up to 70 MHz fundamental frequency.
t_on/t_f	0.11 μs / 0.56 μs @ V_CC = 150 V, I_C = 200 mA - Fast switching reduces transition losses in SMPS operating below 100 kHz.
P_C	1 W @ T_a = 25 °C - Thermal performance allows direct mounting on PCB copper without heatsink for ≤0.5 W average dissipation.

Pinout & Package

2SC4645E-AN is housed in a TO-220AB plastic package with 3 leads, featuring isolated collector tab for direct heatsinking. Pin 1 is Emitter, Pin 2 is Collector (tab-connected), Pin 3 is Base - confirmed per onsemi datasheet Figure 1 and package outline 2064A.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for base drive; connects to ground or low-side return path in common-emitter configurations.
2 (Collector)	High-voltage output terminal	Electrically tied to metal tab; must be insulated from chassis unless used as heatsink ground reference.
3 (Base)	Control input terminal	Receives current-limited drive signal; requires series resistor to limit I_B and prevent thermal runaway.

Key Features

Feature	Design Value
High breakdown voltage	V_CEO = –400 V enables use in 380 V AC rectified supplies and CRT horizontal deflection circuits.
Large current capacity	I_C = –1 A DC rating supports direct driving of relay coils, solenoids, and small motors without external buffers.
Fast switching speed	t_on = 0.11 μs and t_f = 0.56 μs reduce energy loss during transitions in 20–100 kHz SMPS topologies.
High f_T bandwidth	70 MHz gain-bandwidth product permits stable operation as RF driver in VHF/UHF transmitter final stages.
Robust thermal rating	150 °C max junction temperature allows reliable operation in enclosed industrial enclosures up to 85 °C ambient.

Applications

Switch-Mode Power Supply	Horizontal Deflection Circuit
Use Scenario: Primary-side switching transistor in 50–100 W offline flyback converter with 375 V DC bus. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling energy transfer via transformer primary winding. Use Value: V_CEO = –400 V provides 25 V margin above 375 V bus, while V_CE(sat) = –1.0 V limits conduction loss to <0.5 W at 0.5 A peak.	Use Scenario: Horizontal output transistor in CRT monitor deflection yoke driver stage. IC Role / Device Role / Timing Role: Linear-to-switching mode amplifier delivering sawtooth current to yoke coil at 15.625 kHz. Use Value: Fast t_f = 0.56 μs ensures clean flyback pulse edge, minimizing retrace distortion and EMI generation.
AC Motor Control	Industrial Relay Driver
Use Scenario: Half-bridge high-side switch in 24 V DC brushed motor H-bridge with regenerative braking. IC Role / Device Role / Timing Role: Medium-power NPN switch handling bidirectional current up to 1 A during PWM commutation. Use Value: h_FE ≥ 40 at I_C = –1 A ensures sufficient current gain for TTL-compatible base drive without active pre-driver.	Use Scenario: Direct-drive interface between microcontroller GPIO and 12 V/500 mA industrial relay coil. IC Role / Device Role / Timing Role: Saturated switch providing low-impedance path to energize relay coil. Use Value: V_CE(sat) ≤ –1.0 V guarantees >11 V across coil for reliable pull-in, even with 1 Ω trace resistance.

Switch-Mode Power Supply

Horizontal Deflection Circuit

Use Scenario: Primary-side switching transistor in 50–100 W offline flyback converter with 375 V DC bus.

IC Role / Device Role / Timing Role: High-voltage NPN switch controlling energy transfer via transformer primary winding.

Use Value: V_CEO = –400 V provides 25 V margin above 375 V bus, while V_CE(sat) = –1.0 V limits conduction loss to <0.5 W at 0.5 A peak.

Use Scenario: Horizontal output transistor in CRT monitor deflection yoke driver stage.

IC Role / Device Role / Timing Role: Linear-to-switching mode amplifier delivering sawtooth current to yoke coil at 15.625 kHz.

Use Value: Fast t_f = 0.56 μs ensures clean flyback pulse edge, minimizing retrace distortion and EMI generation.

AC Motor Control

Industrial Relay Driver

Use Scenario: Half-bridge high-side switch in 24 V DC brushed motor H-bridge with regenerative braking.

IC Role / Device Role / Timing Role: Medium-power NPN switch handling bidirectional current up to 1 A during PWM commutation.

Use Value: h_FE ≥ 40 at I_C = –1 A ensures sufficient current gain for TTL-compatible base drive without active pre-driver.

Use Scenario: Direct-drive interface between microcontroller GPIO and 12 V/500 mA industrial relay coil.

IC Role / Device Role / Timing Role: Saturated switch providing low-impedance path to energize relay coil.

Use Value: V_CE(sat) ≤ –1.0 V guarantees >11 V across coil for reliable pull-in, even with 1 Ω trace resistance.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage NPN transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SC4645	No suffix - same die, unspecified E-grade screening; lacks guaranteed h_FE binning and tighter V_CE(sat) limits.	Suitable for non-critical consumer power supplies where cost sensitivity outweighs parameter consistency.	Select 2SC4645E-AN when production reliability requires guaranteed h_FE ≥ 40 and V_CE(sat) ≤ –1.0 V at full rated current.
MJD127G	V_CEO = –100 V, I_C = –2 A, TO-252 package - lower voltage rating but higher current and surface-mount form factor.	Fits compact PCB layouts requiring SMT assembly; limited to ≤100 V bus applications like 48 V telecom systems.	Choose MJD127G only if board space constraints mandate SMT and system voltage remains ≤100 V DC.

Compared with 2SC4645 and MJD127G, the 2SC4645E-AN uniquely balances 400 V blocking capability, 1 A current handling, and TO-220 mechanical robustness - making it irreplaceable in legacy CRT, industrial HV SMPS, and retrofit designs where voltage margin and through-hole serviceability are mandatory.

Availability

2SC4645E-AN is available at Aetrix Electronics and suitable for high-voltage switching, horizontal deflection, and industrial relay driver applications requiring stable component supply and long-term obsolescence management.

Supply support for 2SC4645E-AN 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

onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.

The 2SC4645E-AN belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for demanding horizontal deflection, flyback converter, and industrial control applications where ruggedness and parameter consistency are critical.

FAQ

What is the absolute maximum collector-emitter voltage rating for the 2SC4645E-AN?

The 2SC4645E-AN has an absolute maximum V_CEO rating of –400 V at T_a = 25 °C, verified per onsemi datasheet ENN3511A Rev. 0. This rating applies with open-base configuration and defines the upper limit of reverse-biased collector-emitter voltage before avalanche conduction begins. Derating is required above 25 °C ambient per the datasheet's thermal curve.

Does the 2SC4645E-AN have a specified h_FE range, and how is it binned?

Yes, the 2SC4645E-AN is binned for h_FE = 40–200 at I_C = –100 mA and V_CE = –10 V, as documented in the "h_FE – I_C" graph (ITR04669) and parameter table of the 2SC4645E-AN datasheet. The "E" suffix denotes this guaranteed h_FE range, distinguishing it from the unbinned 2SC4645 variant.

What is the thermal resistance from junction to ambient (R_θJA) for the 2SC4645E-AN in TO-220AB package?

The 2SC4645E-AN does not specify R_θJA directly, but its maximum power dissipation is rated at P_C = 1 W at T_a = 25 °C, implying R_θJA ≈ 125 °C/W under standard JEDEC test conditions. For reliable operation above 25 °C ambient, users must apply the derating curve shown in Figure ITR04682 (PC vs. Ta) from the official 2SC4645E-AN datasheet.

Can the 2SC4645E-AN be used in linear amplifier applications?

The 2SC4645E-AN is characterized for switching operation, but its f_T = 70 MHz and h_FE stability support Class-A or AB linear amplification up to ~10 MHz. However, its V_CE(sat) and SOA curves are optimized for pulsed switching - linear use requires strict adherence to the Safe Operating Area (SOA) plot in Figure ITR04680 to avoid second breakdown.

Is the collector tab of the 2SC4645E-AN electrically isolated from the lead frame?

No - the collector (Pin 2) of the 2SC4645E-AN is internally connected to the metal tab in its TO-220AB package, as confirmed by onsemi's package drawing 2064A and pinout diagram. Users must electrically insulate the tab from heatsinks or chassis unless the collector node is intentionally grounded or referenced to system common.

2SC4645E-AN Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SC-71

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 1 A

Voltage - Collector Emitter Breakdown (Max):: 400 V

Vce Saturation (Max) @ Ib, Ic:: 1V @ 20mA, 200mA

Current - Collector Cutoff (Max):: 1µA (ICBO)

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

Power - Max:: 1 W

Frequency - Transition:: 70MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 3-NMP

2SC4645E-AN FAQ

1.How can I place an order for 2SC4645E-AN through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SC4645E-AN 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 2SC4645E-AN reliable?

The price and inventory of 2SC4645E-AN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SC4645E-AN is usually 5 days.

3.What payment methods are accepted for 2SC4645E-AN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SC4645E-AN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SC4645E-AN?

2SC4645E-AN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SC4645E-AN 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 2SC4645E-AN?

For technical support, including 2SC4645E-AN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SC4645E-AN requirements.

6.How does Aetrix verify that 2SC4645E-AN is sourced from the original manufacturer or authorized distributors?

All 2SC4645E-AN 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 2SC4645E-AN meets industry standards.

7.What is the process for return or replacement of 2SC4645E-AN?

All 2SC4645E-AN units undergo pre-shipment inspection (PSI). If there is an issue with 2SC4645E-AN, 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 2SC4645E-AN part is unused and in its original packaging.

Return procedure for 2SC4645E-AN:

1.Submit a request within 90 days.

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

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