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

Vishay Siliconix SI9433BDY-T1-E3

Name: SI9433BDY-T1-E3
Brand: Vishay Siliconix
SKU: SI9433BDY-T1-E3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI9433BDY-T1-E3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: SI9433BDY-T1-E3.pdf

Description:: MOSFET P-CH 20V 4.5A 8SO

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Product details

Overview

SI9433BDY-T1-E3 from Vishay Siliconix is a P-channel enhancement-mode MOSFET rated for -20 V drain-source voltage, 0.040 Ω R_DS(on) at V_GS = -4.5 V, and -6.2 A continuous drain current at T_A = 25 °C. It operates in surface-mount SO-8 package and serves as a high-side load switch or reverse-polarity protection device in DC power rails.

For engineers reviewing the SI9433BDY-T1-E3 datasheet, SI9433BDY-T1-E3 pinout, SI9433BDY-T1-E3 application, or SI9433BDY-T1-E3 equivalent, key selection criteria include verified R_DS(on) at low gate drive (-2.7 V), thermal resistance (R_thJA = 80 °C/W steady-state), diode forward voltage (V_SD = -0.76 V), and SO-8 footprint compatibility with IPC-7351B land patterns.

Technical Context

This MOSFET uses planar trench-gate silicon technology optimized for low gate charge (Q_g = 8.8 nC typical) and fast switching (t_d(on) = 40 ns, t_f = 30 ns). Its negative threshold voltage (V_GS(th) = -0.6 to -1.5 V) enables reliable turn-on with logic-level gate drivers.

The device integrates an intrinsic body diode with reverse recovery time (t_rr = 35 ns) and forward voltage (V_SD = -0.76 V at I_S = -2.6 A), supporting synchronous rectification and flyback energy recirculation in buck converters and hot-swap circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	-20 V maximum - supports 12 V and 15 V rail protection without derating
R_DS(on)	0.040 Ω at V_GS = -4.5 V - limits conduction loss to <1.5 W at 6.2 A
I_D (continuous)	-6.2 A at T_A = 25 °C - suitable for medium-power load switching
Q_g	8.8 nC typical - enables efficient 1 MHz switching with ≤6 Ω gate resistor
V_GS(th)	-0.6 to -1.5 V - ensures turn-on with 3.3 V microcontroller GPIO
R_thJA	80 °C/W steady-state - requires ≤15 °C/W heatsinking for 1.3 W dissipation at 150 °C junction
V_SD	-0.76 V at I_S = -2.6 A - reduces reverse-current power loss in OR-ing applications

Pinout & Package

SO-8 (MS-012) surface-mount package with standard narrow-body dimensions (4.9 mm × 3.9 mm × 1.5 mm), JEDEC-compliant lead pitch (1.27 mm), and exposed drain pad for thermal enhancement.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 5	Source	Common source connection; pins 1–5 internally bonded to reduce source inductance
6, 7, 8	Drain	High-current drain path; pins 6–8 tied to exposed thermal pad for PCB heat sinking
3	Gate	Single gate input; pin 3 isolated from source/drain metallization per SO-8 layout

Key Features

Feature	Design Value
Halogen-free construction	Complies with IEC 61249-2-21 - meets automotive and industrial RoHS+halogen restrictions
Low R_DS(on) at -2.7 V	0.060 Ω - enables direct interface with 2.7 V logic without level-shifting
Fast switching speed	t_f = 30 ns - minimizes overlap loss in synchronous buck topologies
Robust safe operating area	Rated for 20 A pulsed drain current - withstands inrush and short-circuit transients
Thermal performance	R_thJF = 20 °C/W - allows direct thermal coupling to PCB copper pour via exposed drain pad

Applications

Reverse Polarity Protection	Hot-Swap Controller
Use Scenario: Prevents damage when a 12 V battery is connected backward to a system input. IC Role / Device Role / Timing Role: High-side P-channel MOSFET configured as ideal diode with gate driven by dedicated controller or resistor-divider. Use Value: Replaces Schottky diode with 0.040 Ω R_DS(on), reducing voltage drop from ~0.4 V to <0.25 V at 6 A and eliminating thermal runaway risk.	Use Scenario: Enables live insertion of a board into a backplane without disrupting upstream power. IC Role / Device Role / Timing Role: Load switch controlling inrush current via controlled gate ramp using RC network or dedicated IC. Use Value: Limits peak inrush to <10 A with <100 µs turn-on delay, preventing bus droop and contact arcing during plug-in.
OR-ing Diode Replacement	DC-DC Converter Synchronous Rectifier
Use Scenario: Combines two redundant 5 V supplies while blocking reverse current flow between them. IC Role / Device Role / Timing Role: Back-to-back P-channel MOSFET pair used as active OR-ing element with gate tied to respective supply rail. Use Value: Achieves bidirectional blocking and <0.1 V forward drop vs. 0.35 V for Schottky, improving efficiency by >1.2% at full load.	Use Scenario: Replaces catch diode in non-isolated buck converter operating at 500 kHz. IC Role / Device Role / Timing Role: Synchronous rectifier switched complementary to high-side FET, using body diode conduction and gate drive timing. Use Value: Reduces conduction loss by 65% versus 40 V Schottky, enabling >92% efficiency at 5 A output with 12 V input.

Reverse Polarity Protection

Hot-Swap Controller

Use Scenario: Prevents damage when a 12 V battery is connected backward to a system input.

IC Role / Device Role / Timing Role: High-side P-channel MOSFET configured as ideal diode with gate driven by dedicated controller or resistor-divider.

Use Value: Replaces Schottky diode with 0.040 Ω R_DS(on), reducing voltage drop from ~0.4 V to <0.25 V at 6 A and eliminating thermal runaway risk.

Use Scenario: Enables live insertion of a board into a backplane without disrupting upstream power.

IC Role / Device Role / Timing Role: Load switch controlling inrush current via controlled gate ramp using RC network or dedicated IC.

Use Value: Limits peak inrush to <10 A with <100 µs turn-on delay, preventing bus droop and contact arcing during plug-in.

OR-ing Diode Replacement

DC-DC Converter Synchronous Rectifier

Use Scenario: Combines two redundant 5 V supplies while blocking reverse current flow between them.

IC Role / Device Role / Timing Role: Back-to-back P-channel MOSFET pair used as active OR-ing element with gate tied to respective supply rail.

Use Value: Achieves bidirectional blocking and <0.1 V forward drop vs. 0.35 V for Schottky, improving efficiency by >1.2% at full load.

Use Scenario: Replaces catch diode in non-isolated buck converter operating at 500 kHz.

IC Role / Device Role / Timing Role: Synchronous rectifier switched complementary to high-side FET, using body diode conduction and gate drive timing.

Use Value: Reduces conduction loss by 65% versus 40 V Schottky, enabling >92% efficiency at 5 A output with 12 V input.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
IRF7425PBF	R_DS(on) = 0.055 Ω at V_GS = -4.5 V; Q_g = 12 nC; SO-8 package	Higher gate charge increases switching loss in high-frequency designs	Prefer SI9433BDY-T1-E3 for sub-1 MHz switching where gate drive strength is limited
DMG2305UVT-7	R_DS(on) = 0.045 Ω at V_GS = -4.5 V; V_DS = -20 V; SOT-23-6 package	Smaller SOT-23-6 package limits power dissipation to 0.7 W (vs. 1.3 W for SO-8)	Select SI9433BDY-T1-E3 when ≥1 W continuous power handling or PCB thermal relief is required

Compared with IRF7425PBF and DMG2305UVT-7, the SI9433BDY-T1-E3 delivers lower gate charge and higher SO-8 thermal capability, making it optimal for medium-power, space-constrained hot-swap and reverse-protection circuits requiring stable R_DS(on) below -2.7 V gate drive.

Availability

SI9433BDY-T1-E3 is available at Aetrix Electronics and suitable for reverse polarity protection, hot-swap control, and OR-ing diode replacement applications requiring stable component supply across industrial automation, telecom power systems, and embedded computing platforms.

Supply support for SI9433BDY-T1-E3 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

Vishay Siliconix is a global leader in discrete semiconductors, specializing in MOSFETs, diodes, optoelectronics, and passive components with emphasis on reliability and power efficiency.

The Si9433BDY product line targets high-efficiency DC power management in compact, thermally constrained environments-designed specifically for low-voltage P-channel switching where gate drive headroom is limited.

FAQ

What is the maximum continuous drain current rating for SI9433BDY-T1-E3 at 70 °C ambient temperature?

The SI9433BDY-T1-E3 supports -5.0 A continuous drain current at T_A = 70 °C, as specified in the Absolute Maximum Ratings table under "Continuous Drain Current (T_J = 150 °C)" with derating applied. This value assumes proper PCB thermal design with ≥1 in² of 2-oz copper connected to the drain pad.

Does SI9433BDY-T1-E3 have a halogen-free construction?

Yes, SI9433BDY-T1-E3 is halogen-free according to IEC 61249-2-21 and complies with RoHS Directive 2002/95/EC. The "-E3" suffix explicitly denotes lead-free and halogen-free packaging, confirmed in the Ordering Information section of Vishay document 72755.

Can SI9433BDY-T1-E3 be driven directly by a 3.3 V microcontroller GPIO?

Yes, SI9433BDY-T1-E3 has a gate threshold voltage range of -0.6 V to -1.5 V and achieves 0.060 Ω R_DS(on) at V_GS = -2.7 V, enabling full enhancement with 3.3 V logic. No level shifter is needed, though a series gate resistor (≤10 Ω) is recommended to dampen ringing.

What is the thermal resistance from junction to ambient for SI9433BDY-T1-E3 in steady-state conditions?

The SI9433BDY-T1-E3 has a maximum steady-state junction-to-ambient thermal resistance (R_thJA) of 95 °C/W, with a typical value of 80 °C/W. This rating assumes surface mounting on FR4 with standard SO-8 land pattern per Vishay Application Note 826.

Is the body diode of SI9433BDY-T1-E3 suitable for synchronous rectification in a buck converter?

Yes, the SI9433BDY-T1-E3 body diode has a forward voltage of -0.76 V at -2.6 A and reverse recovery time of 35 ns, making it viable for synchronous rectification up to ~1 MHz in buck converters. Gate timing must ensure dead-time control to prevent shoot-through.

SI9433BDY-T1-E3 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Last Time Buy

FET Type:: P-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 20 V

Current - Continuous Drain (Id) @ 25°C:: 4.5A (Ta)

Drive Voltage (Max Rds On, Min Rds On):: 2.7V, 4.5V

Rds On (Max) @ Id, Vgs:: 40mOhm @ 6.2A, 4.5V

Vgs(th) (Max) @ Id:: 1.5V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 14 nC @ 4.5 V

Vgs (Max):: ±12V

Input Capacitance (Ciss) (Max) @ Vds:: -

FET Feature:: -

Power Dissipation (Max):: 1.3W (Ta)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

SI9433BDY-T1-E3 FAQ

1.How can I place an order for SI9433BDY-T1-E3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI9433BDY-T1-E3 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 SI9433BDY-T1-E3 reliable?

The price and inventory of SI9433BDY-T1-E3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI9433BDY-T1-E3 is usually 5 days.

3.What payment methods are accepted for SI9433BDY-T1-E3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI9433BDY-T1-E3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI9433BDY-T1-E3?

SI9433BDY-T1-E3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI9433BDY-T1-E3 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 SI9433BDY-T1-E3?

For technical support, including SI9433BDY-T1-E3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI9433BDY-T1-E3 requirements.

6.How does Aetrix verify that SI9433BDY-T1-E3 is sourced from the original manufacturer or authorized distributors?

All SI9433BDY-T1-E3 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 SI9433BDY-T1-E3 meets industry standards.

7.What is the process for return or replacement of SI9433BDY-T1-E3?

All SI9433BDY-T1-E3 units undergo pre-shipment inspection (PSI). If there is an issue with SI9433BDY-T1-E3, 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 SI9433BDY-T1-E3 part is unused and in its original packaging.

Return procedure for SI9433BDY-T1-E3:

1.Submit a request within 90 days.

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

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