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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Toshiba Semiconductor and Storage TK8A45D(STA4,Q,M)

Name: TK8A45D(STA4,Q,M)
Brand: Toshiba Semiconductor and Storage
SKU: TK8A45D(STA4,Q,M)
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TK8A45D(STA4,Q,M)

Manufacturer:: Toshiba Semiconductor and Storage

Category:: FETs, MOSFETs

Package:: TO-220-3 Full Pack

Datasheet:: TK8A45D(STA4,Q,M).pdf

Description:: MOSFET N-CH 450V 8A TO220SIS

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Product details

Overview

TK8A45D(STA4,Q,M) from Toshiba is a silicon N-channel power MOSFET in the π-MOSⅣ family, designed for high-voltage switching applications. It delivers 450 V drain-source breakdown voltage, 8 A DC drain current, and low on-resistance of 0.73 Ω (typ.) at V_GS = 10 V, enabling efficient operation in offline SMPS and industrial power supplies.

For engineers reviewing the TK8A45D(STA4,Q,M) datasheet, TK8A45D(STA4,Q,M) pinout, TK8A45D(STA4,Q,M) application, or TK8A45D(STA4,Q,M) equivalent, key selection criteria include avalanche energy rating (173 mJ), gate threshold voltage range (2.4–4.4 V), thermal resistance (3.57 °C/W channel-to-case), and TO-220SIS package compatibility with heatsink mounting.

Technical Context

This device operates in enhancement mode with a gate threshold voltage specified between 2.4 V and 4.4 V at V_DS = 10 V and I_D = 1 mA, ensuring reliable turn-on under standard logic-level drive. Its low R_DS(ON) and high forward transfer admittance (|Y_fs| = 3.8 S typ.) support fast switching and high-current conduction in hard-switched topologies.

The TK8A45D(STA4,Q,M) features built-in body diode with reverse recovery time of 1300 ns and Q_rr of 9.1 µC, making it suitable for freewheeling paths in flyback and forward converters. Its single-pulse avalanche capability (E_AS = 173 mJ) provides robustness against transient overvoltage events without external snubbers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	450 V - supports primary-side switching in universal-input AC/DC adapters up to 265 V_AC
R_DS(ON)	0.73 Ω (typ.) - reduces conduction loss and junction heating at 4 A load current
I_D (DC)	8 A - enables continuous operation in 60–100 W power supplies with adequate heatsinking
E_AS	173 mJ - withstands single-energy avalanche events during MOSFET turn-off transients
V_th	2.4–4.4 V - compatible with 5 V and 12 V gate drivers; avoids spurious turn-on near ground
C_iss	700 pF - determines gate drive power requirement and influences switching speed
R_th(ch-c)	3.57 °C/W - allows thermal design with standard TO-220 heatsinks for ≤35 W dissipation

Pinout & Package

TK8A45D(STA4,Q,M) is housed in a TO-220SIS (JEITA SC-67, Toshiba 2-10U1S) package with insulated tab, enabling direct mounting to heatsinks without electrical isolation hardware. The package weighs 1.7 g and features three leads in a single-row configuration.

Pin/Terminal	Circuit Role	Design Meaning
1	Gate (G)	Controls channel conduction; requires <2.4 V to ensure full off-state and >4.4 V for guaranteed saturation
2	Drain (D)	High-voltage terminal connected to transformer primary or bus rail; electrically tied to metal tab
3	Source (S)	Return path for load current; referenced to control circuit ground; defines V_GS measurement point

Key Features

Feature	Design Value
Low R_DS(ON)	0.73 Ω typ. minimizes I²R losses in high-duty-cycle SMPS designs, improving efficiency by ~0.8% at full load
High \|Y_fs\|	3.8 S typ. enables strong transconductance for stable gain in current-sense amplifier interfaces
Avalanche-rated	173 mJ single-pulse rating permits operation without clamping circuits in non-isolated flyback converters
Enhancement-mode V_th	2.4–4.4 V range ensures compatibility with both 3.3 V and 5 V microcontroller gate drivers
TO-220SIS insulation	Electrically isolated metal tab eliminates need for insulating washers when mounted to grounded heatsinks

Applications

Industrial AC/DC Power Supplies	LED Driver Circuits
Use Scenario: 75 W open-frame power supply for factory automation controllers operating from 85–265 V_AC. IC Role / Device Role / Timing Role: Primary-side switching MOSFET in discontinuous conduction mode (DCM) flyback topology. Use Value: 450 V V_DSS and 173 mJ E_AS eliminate need for external RCD snubber, reducing BOM count and board area.	Use Scenario: Constant-current LED driver for high-bay lighting fixtures with surge immunity requirements. IC Role / Device Role / Timing Role: High-side switch controlling bulk capacitor discharge and LED string current regulation. Use Value: Low leakage (I_DSS ≤ 10 µA at 450 V) prevents standby power drift and maintains dimming stability over temperature.
Switching Voltage Regulators	Motor Drive Inverters
Use Scenario: 48 V input buck converter supplying 12 V/5 A to embedded control modules in telecom infrastructure. IC Role / Device Role / Timing Role: Synchronous rectifier MOSFET in secondary-side synchronous rectification stage. Use Value: 0.73 Ω R_DS(ON) reduces conduction loss by 35% compared to 1.2 Ω alternatives, lowering thermal stress on PCB copper.	Use Scenario: Half-bridge leg in 24 V BLDC motor controller for HVAC blowers. IC Role / Device Role / Timing Role: Low-side switching element handling PWM commutation at 20 kHz. Use Value: Fast reverse recovery (t_rr = 1300 ns) and low Q_rr (9.1 µC) suppress shoot-through risk and reduce switching losses during dead-time transitions.

Industrial AC/DC Power Supplies

LED Driver Circuits

Use Scenario: 75 W open-frame power supply for factory automation controllers operating from 85–265 V_AC.

IC Role / Device Role / Timing Role: Primary-side switching MOSFET in discontinuous conduction mode (DCM) flyback topology.

Use Value: 450 V V_DSS and 173 mJ E_AS eliminate need for external RCD snubber, reducing BOM count and board area.

Use Scenario: Constant-current LED driver for high-bay lighting fixtures with surge immunity requirements.

IC Role / Device Role / Timing Role: High-side switch controlling bulk capacitor discharge and LED string current regulation.

Use Value: Low leakage (I_DSS ≤ 10 µA at 450 V) prevents standby power drift and maintains dimming stability over temperature.

Switching Voltage Regulators

Motor Drive Inverters

Use Scenario: 48 V input buck converter supplying 12 V/5 A to embedded control modules in telecom infrastructure.

IC Role / Device Role / Timing Role: Synchronous rectifier MOSFET in secondary-side synchronous rectification stage.

Use Value: 0.73 Ω R_DS(ON) reduces conduction loss by 35% compared to 1.2 Ω alternatives, lowering thermal stress on PCB copper.

Use Scenario: Half-bridge leg in 24 V BLDC motor controller for HVAC blowers.

IC Role / Device Role / Timing Role: Low-side switching element handling PWM commutation at 20 kHz.

Use Value: Fast reverse recovery (t_rr = 1300 ns) and low Q_rr (9.1 µC) suppress shoot-through risk and reduce switching losses during dead-time transitions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel power MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP8NK45Z	450 V V_DSS, 7.5 A I_D, R_DS(ON) = 0.85 Ω, Zener-protected gate	Higher R_DS(ON) increases conduction loss; integrated gate protection simplifies layout	Prefer when gate drive reliability in noisy environments outweighs efficiency targets
IRF740B	400 V V_DSS, 10 A I_D, R_DS(ON) = 0.55 Ω, TO-220AB package (non-insulated)	Lower voltage rating limits use to 230 V_AC max inputs; uninsulated tab requires isolation hardware	Choose only if system input is strictly ≤230 V_AC and heatsink isolation is already implemented

Compared with STP8NK45Z and IRF740B, the TK8A45D(STA4,Q,M) offers superior avalanche ruggedness (173 mJ vs. 120 mJ and 85 mJ), TO-220SIS insulation eliminating mounting complexity, and tighter V_th distribution-making it optimal for cost-sensitive, high-reliability industrial SMPS where layout simplicity and transient robustness are prioritized.

Availability

TK8A45D(STA4,Q,M) is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, LED driver circuits, and switching voltage regulators requiring stable component supply across multi-year production cycles.

Supply support for TK8A45D(STA4,Q,M) 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

Toshiba Electronic Devices & Storage Corporation designs and manufactures discrete semiconductors, power devices, and logic ICs with emphasis on reliability, efficiency, and industrial-grade performance.

The TK8A45D(STA4,Q,M) belongs to Toshiba's π-MOSⅣ high-voltage power MOSFET product line, engineered specifically for rugged, high-efficiency switching in offline power conversion systems up to 100 W.

FAQ

What is the maximum continuous drain current rating for TK8A45D(STA4,Q,M)?

The TK8A45D(STA4,Q,M) has a DC drain current rating of 8 A at T_c = 25 °C. This value decreases with increasing case temperature per the derating curve in Figure 8.11; at 100 °C case temperature, the usable I_D drops to approximately 4.5 A. Thermal design must ensure channel temperature remains below 150 °C under worst-case load conditions.

Does TK8A45D(STA4,Q,M) have an integrated body diode, and what are its key parameters?

Yes, the TK8A45D(STA4,Q,M) includes a monolithic body diode. Its key parameters include reverse recovery time (t_rr) of 1300 ns and reverse recovery charge (Q_rr) of 9.1 µC, measured at I_DR = 8 A, V_GS = 0 V, and -dI_DR/dt = 100 A/µs. These values impact switching loss and EMI in hard-switched topologies.

What is the gate threshold voltage range for TK8A45D(STA4,Q,M), and how does it affect drive circuit design?

The gate threshold voltage (V_th) for TK8A45D(STA4,Q,M) is specified from 2.4 V to 4.4 V at V_DS = 10 V and I_D = 1 mA. This range means a 5 V gate driver ensures full enhancement, while 3.3 V may yield marginal conduction. Designers should verify gate drive voltage margin above 4.4 V to guarantee low R_DS(ON) across process and temperature variation.

Is TK8A45D(STA4,Q,M) RoHS compliant, and what marking indicates compliance?

Yes, TK8A45D(STA4,Q,M) is RoHS compliant. Per Toshiba documentation, RoHS-compliant units are marked with an underlined lot number and carry [[G]]/RoHS COMPATIBLE or [[G]]/RoHS [[Pb]] labeling. Non-RoHS versions show unmarked or [[Pb]]/INCLUDES > MCV indicators. Always verify marking on received units or consult Toshiba's latest environmental reports.

What thermal resistance values apply to TK8A45D(STA4,Q,M), and how are they used in thermal design?

The TK8A45D(STA4,Q,M) specifies R_th(ch-c) = 3.57 °C/W (channel-to-case) and R_th(ch-a) = 62.5 °C/W (channel-to-ambient). R_th(ch-c) is used with heatsink thermal resistance to calculate junction temperature rise above case; R_th(ch-a) applies only in free-air conditions without heatsink and is rarely used in production designs due to its high value.

TK8A45D(STA4,Q,M) Specifications

Product attributes: Attribute value

Manufacturer:: Toshiba Semiconductor and Storage

Series:: π-MOSVII

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Active

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 450 V

Current - Continuous Drain (Id) @ 25°C:: 8A (Ta)

Drive Voltage (Max Rds On, Min Rds On):: 10V

Rds On (Max) @ Id, Vgs:: 900mOhm @ 4A, 10V

Vgs(th) (Max) @ Id:: 4.4V @ 1mA

Gate Charge (Qg) (Max) @ Vgs:: 16 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 700 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 35W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220SIS

TK8A45D(STA4,Q,M) FAQ

1.How can I place an order for TK8A45D(STA4,Q,M) through Aetrix?

Please submit a Request for Quotation (RFQ) for TK8A45D(STA4,Q,M) 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 TK8A45D(STA4,Q,M) reliable?

The price and inventory of TK8A45D(STA4,Q,M) are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TK8A45D(STA4,Q,M) is usually 5 days.

3.What payment methods are accepted for TK8A45D(STA4,Q,M)?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TK8A45D(STA4,Q,M) transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TK8A45D(STA4,Q,M)?

TK8A45D(STA4,Q,M) orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TK8A45D(STA4,Q,M) 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 TK8A45D(STA4,Q,M)?

For technical support, including TK8A45D(STA4,Q,M) datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TK8A45D(STA4,Q,M) requirements.

6.How does Aetrix verify that TK8A45D(STA4,Q,M) is sourced from the original manufacturer or authorized distributors?

All TK8A45D(STA4,Q,M) 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 TK8A45D(STA4,Q,M) meets industry standards.

7.What is the process for return or replacement of TK8A45D(STA4,Q,M)?

All TK8A45D(STA4,Q,M) units undergo pre-shipment inspection (PSI). If there is an issue with TK8A45D(STA4,Q,M), 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 TK8A45D(STA4,Q,M) part is unused and in its original packaging.

Return procedure for TK8A45D(STA4,Q,M):

1.Submit a request within 90 days.

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

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