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

onsemi 2SC3645S-TD-E

Name: 2SC3645S-TD-E
Brand: onsemi
SKU: 2SC3645S-TD-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SC3645S-TD-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-243AA

Datasheet:: 2SC3645S-TD-E.pdf

Description:: TRANS NPN 160V 0.14A PCP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SC3645S-TD-E from onsemi is an NPN epitaxial planar silicon transistor designed for high-voltage switching and predriver applications, featuring V_CEO = 160 V, f_T = 150 MHz, Cob = 3.0 pF (typ), V_CE(sat) = 0.07 V (typ) at I_C = 50 mA / I_B = 5 mA, and P_C = 500 mW on PCB.

For engineers reviewing the 2SC3645S-TD-E datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage capability, fast switching (t_on = 0.1 µs, t_f = 0.1 µs), low output capacitance, linear h_FE behavior, and compatibility with high-density hybrid IC layouts.

Technical Context

This device employs FBET (Flat Base Epitaxial Transistor) process technology to achieve high breakdown voltage and excellent h_FE linearity across collector current. Its low Cob and fast switching times support stable operation in high-frequency switching stages.

The 2SC3645S-TD-E operates as a discrete NPN switch or predriver in DC-DC converters, display drivers, and pulse generators where V_CEO ≥ 160 V and f_T ≥ 150 MHz are required, with thermal performance validated on ceramic board (250 mm² × 0.8 mm).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - supports high-side switching in 100–150 V bus applications without secondary breakdown risk
f_T	150 MHz - enables reliable operation up to ~50 MHz square-wave switching with margin
Cob	3.0 pF (typ) - minimizes Miller effect and improves turn-off speed in high-gain stages
V_CE(sat)	0.07 V (typ) at I_C/I_B = 50 mA/5 mA - reduces conduction loss in saturated-switching configurations
h_FE	140–400 (rank S/T) - provides predictable current gain control across production lots for bias stability
P_C	500 mW (on PCB) - defines maximum continuous power dissipation under standard mounting conditions
t_on/t_f	0.1 µs each - ensures sub-100 ns edge transitions suitable for >5 MHz pulse generation

Pinout & Package

Package: TO-92MOD (SANYO PCP), molded plastic with 1.6 mm body width, 4.5 mm height, and 2.5 mm lead pitch. Marking "CA" identifies 2SC3645 variant.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Current-controlled input node	Receives base drive to saturate or cut off collector-emitter path; requires current-limiting resistor in series
2 (Collector)	High-voltage output terminal	Connected to load or next stage; rated for 160 V V_CEO and handles up to 140 mA DC current
3 (Emitter)	Reference and return path	Typically grounded or tied to negative rail; carries full collector current and sets emitter-follower bias point

Key Features

Feature	Design Value
FBET process technology	Enables precise base-width control for consistent h_FE linearity and reduced Cob vs. conventional planar transistors
Ultrasmall package footprint	TO-92MOD dimensions (2.5 × 4.0 × 1.6 mm) allow placement in <1.5 mm² PCB area for space-constrained hybrid modules
High-voltage capability	V_CEO = 160 V and V_CBO = 180 V permit direct use in flyback snubbers and relay drivers without external clamping
Fast switching performance	Combined t_on + t_stg + t_f < 1.7 µs supports clean pulse shaping in timing circuits and LED strobes

Applications

Switch-Mode Power Supply Driver	CCFL/LED Backlight Inverter
Use Scenario: Driving gate of high-voltage MOSFET in flyback converter primary side with 100–150 V input. IC Role / Device Role / Timing Role: NPN predriver amplifying PWM controller output to deliver sufficient peak base current for fast MOSFET turn-on. Use Value: Low V_CE(sat) and high f_T reduce driver losses and preserve rise time integrity at 50–100 kHz switching frequencies.	Use Scenario: Generating high-frequency AC for cold-cathode fluorescent lamp (CCFL) or high-brightness LED string inverters. IC Role / Device Role / Timing Role: Push-pull switching element in Royer or ZVS oscillator topology operating at 20–100 kHz. Use Value: High V_CEO withstands transformer leakage spikes; low Cob minimizes capacitive loading on resonant tank.
LCD Panel Gate Driver	Industrial Pulse Generator
Use Scenario: Level-shifting and amplifying row-select signals in TFT-LCD gate driver ICs requiring ±100 V swing. IC Role / Device Role / Timing Role: High-voltage NPN switch translating logic-level gate pulses to panel-level scan-line voltages. Use Value: Linear h_FE ensures accurate current mirroring across temperature; fast t_f prevents ghosting in high-resolution displays.	Use Scenario: Generating clean, repeatable 10–100 ns pulses for test equipment, laser diode triggering, or time-of-flight sensors. IC Role / Device Role / Timing Role: Saturated switch in monostable multivibrator or pulse-forming network with controlled edge rates. Use Value: Sub-0.2 µs t_on/t_f and minimal storage time enable precise pulse width control down to 50 ns.

Switch-Mode Power Supply Driver

CCFL/LED Backlight Inverter

Use Scenario: Driving gate of high-voltage MOSFET in flyback converter primary side with 100–150 V input.

IC Role / Device Role / Timing Role: NPN predriver amplifying PWM controller output to deliver sufficient peak base current for fast MOSFET turn-on.

Use Value: Low V_CE(sat) and high f_T reduce driver losses and preserve rise time integrity at 50–100 kHz switching frequencies.

Use Scenario: Generating high-frequency AC for cold-cathode fluorescent lamp (CCFL) or high-brightness LED string inverters.

IC Role / Device Role / Timing Role: Push-pull switching element in Royer or ZVS oscillator topology operating at 20–100 kHz.

Use Value: High V_CEO withstands transformer leakage spikes; low Cob minimizes capacitive loading on resonant tank.

LCD Panel Gate Driver

Industrial Pulse Generator

Use Scenario: Level-shifting and amplifying row-select signals in TFT-LCD gate driver ICs requiring ±100 V swing.

IC Role / Device Role / Timing Role: High-voltage NPN switch translating logic-level gate pulses to panel-level scan-line voltages.

Use Value: Linear h_FE ensures accurate current mirroring across temperature; fast t_f prevents ghosting in high-resolution displays.

Use Scenario: Generating clean, repeatable 10–100 ns pulses for test equipment, laser diode triggering, or time-of-flight sensors.

IC Role / Device Role / Timing Role: Saturated switch in monostable multivibrator or pulse-forming network with controlled edge rates.

Use Value: Sub-0.2 µs t_on/t_f and minimal storage time enable precise pulse width control down to 50 ns.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SC3646S-TD-E	Same package and pinout; h_FE rank T (200–400) vs. 2SC3645S-TD-E's S/T dual marking; identical V_CEO, f_T, and Cob	Preferred where tighter h_FE distribution is needed for matched pair designs or feedback loop stability	Select 2SC3646S-TD-E when h_FE consistency across units is critical; otherwise 2SC3645S-TD-E offers broader gain range
MPSA44	V_CEO = 400 V (higher), f_T = 200 MHz (higher), but Cob = 12 pF (larger), P_C = 625 mW, TO-92 package with different pinout (E-B-C)	Suitable for higher-voltage flybacks (>200 V) but less optimal in high-frequency, low-capacitance stages due to Cob	Choose MPSA44 only when absolute V_CEO > 160 V is mandatory; verify PCB layout compatibility due to E-B-C pin order

Compared with 2SC3645S-TD-E, 2SC3646S-TD-E delivers tighter h_FE tolerance for precision biasing, while MPSA44 trades higher voltage rating for increased output capacitance and incompatible pin assignment-making it a functional alternative only after layout revision.

Availability

2SC3645S-TD-E is available at Aetrix Electronics and suitable for switch-mode power supplies, LCD panel drivers, CCFL/LED backlight inverters, and industrial pulse generators requiring stable component supply and long-term obsolescence management.

Supply support for 2SC3645S-TD-E 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 supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The 2SC3645S-TD-E belongs to onsemi's legacy high-voltage bipolar transistor family, engineered specifically for predriver and switching roles in compact, high-reliability hybrid ICs and power conversion systems.

FAQ

What is the maximum collector-emitter voltage rating for the 2SC3645S-TD-E?

The 2SC3645S-TD-E has a guaranteed V_CEO rating of 160 V at T_a = 25°C, verified per onsemi's Absolute Maximum Ratings table. This allows safe operation in circuits with up to 150 V DC bus voltage, provided derating for temperature and reliability margins is applied per JEDEC guidelines. The 2SC3645S-TD-E also supports V_CBO = 180 V, making it suitable for inductive switching with voltage overshoot.

Does the 2SC3645S-TD-E have a specified gain-bandwidth product?

Yes, the 2SC3645S-TD-E has a typical f_T of 150 MHz at V_CE = 10 V and I_C = 10 mA, as confirmed in the Electrical Characteristics table. This value reflects its suitability for RF predriver and high-speed switching applications up to ~50 MHz, with measured performance stable across the 1–10 mA collector current range shown in the f_T vs. I_C graph on page 3 of the datasheet.

What is the package type and pin configuration of the 2SC3645S-TD-E?

The 2SC3645S-TD-E uses the TO-92MOD (SANYO PCP) package with 1.6 mm body width and standardized 2.54 mm lead spacing. Pin 1 is Base, Pin 2 is Collector, and Pin 3 is Emitter - matching the mechanical drawing on page 2 of the onsemi datasheet. The marking "CA" on the device body confirms the 2SC3645S-TD-E variant within this family.

How does the 2SC3645S-TD-E perform in saturation switching applications?

The 2SC3645S-TD-E achieves V_CE(sat) = 0.07 V (typ) at I_C = 50 mA and I_B = 5 mA, with a maximum of 0.3 V under worst-case conditions. Its low saturation voltage and fast t_on/t_f (0.1 µs each) make it effective in high-efficiency saturated-switching topologies like relay drivers and digital output stages where conduction loss and switching fidelity are critical.

Is the 2SC3645S-TD-E suitable for high-density hybrid IC assembly?

Yes, the 2SC3645S-TD-E was explicitly designed for high-density hybrid ICs, as stated in its Features section. Its ultrasmall TO-92MOD footprint (2.5 × 4.0 × 1.6 mm), low profile, and "CA" marking enable automated placement and reflow in multi-layer hybrid substrates. The FBET process ensures consistent parametric yield, supporting tight layout tolerances in miniaturized power modules containing the 2SC3645S-TD-E.

2SC3645S-TD-E Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-243AA

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:: 140 @ 10mA, 5V

Power - Max:: 500 mW

Frequency - Transition:: 150MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PCP

2SC3645S-TD-E FAQ

1.How can I place an order for 2SC3645S-TD-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SC3645S-TD-E 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 2SC3645S-TD-E reliable?

The price and inventory of 2SC3645S-TD-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SC3645S-TD-E is usually 5 days.

3.What payment methods are accepted for 2SC3645S-TD-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SC3645S-TD-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SC3645S-TD-E?

2SC3645S-TD-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SC3645S-TD-E 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 2SC3645S-TD-E?

For technical support, including 2SC3645S-TD-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SC3645S-TD-E requirements.

6.How does Aetrix verify that 2SC3645S-TD-E is sourced from the original manufacturer or authorized distributors?

All 2SC3645S-TD-E 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 2SC3645S-TD-E meets industry standards.

7.What is the process for return or replacement of 2SC3645S-TD-E?

All 2SC3645S-TD-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SC3645S-TD-E, 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 2SC3645S-TD-E part is unused and in its original packaging.

Return procedure for 2SC3645S-TD-E:

1.Submit a request within 90 days.

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

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