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

Texas Instruments CSD18509Q5BT

Name: CSD18509Q5BT
Brand: Texas Instruments
SKU: CSD18509Q5BT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: CSD18509Q5BT

Manufacturer:: Texas Instruments

Category:: FETs, MOSFETs

Package:: 8-PowerTDFN

Datasheet:: CSD18509Q5BT.pdf

Description:: MOSFET N-CH 40V 100A 8VSON

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Product details

Overview

CSD18509Q5BT from Texas Instruments is an N-channel 40 V, 1.0 mΩ (at V_GS = 10 V) NexFET™ power MOSFET in a VSON-CLIP (DNK) 8-pin 5 mm × 6 mm package, optimized for high-current DC-DC conversion and secondary-side synchronous rectification with ultra-low conduction loss and 150 nC total gate charge.

For engineers reviewing the CSD18509Q5BT datasheet, CSD18509Q5BT pinout, CSD18509Q5BT application, or CSD18509Q5BT equivalent, this device supports high-efficiency 48 V–12 V/5 V point-of-load designs, thermal-limited motor drive H-bridges, and avalanche-rated industrial switching where R_DS(on) stability across temperature and low Q_g/Q_gd ratio are critical selection criteria.

Technical Context

This MOSFET employs a silicon-limited design with 299 A continuous drain current capability at T_C = 25°C and features a low 0.8°C/W junction-to-case thermal resistance. Its gate threshold voltage of 1.8 V (typical) enables direct logic-level drive from 3.3 V or 5 V controllers without level-shifting.

The device integrates a robust body diode with 0.8 V forward voltage at 32 A and 40 nC reverse recovery charge, supporting fast-switching synchronous rectifier operation. Avalanche energy rating of 345 mJ (single-pulse, I_D = 83 A) confirms ruggedness under unclamped inductive switching conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	40 V - Maximum blocking voltage for 36 V nominal input systems with margin
R_DS(on) @ V_GS = 10 V	1.0 mΩ - Enables <1 W conduction loss at 32 A in high-current POL stages
Q_g (10 V)	150 nC - Determines gate driver power requirement and switching loss trade-off
Q_gd	17 nC - Low Miller charge improves dv/dt immunity and hard-switching robustness
V_GS(th)	1.8 V (typ) - Ensures reliable turn-on with standard 3.3 V microcontrollers or PWM ICs
R_θJC	0.8°C/W - Enables >150 W power dissipation with minimal case-to-heatsink ΔT
E_AS	345 mJ - Supports safe operation in flyback or LLC resonant converters with leakage inductance

Pinout & Package

VSON-CLIP (DNK) 8-pin thermally enhanced plastic package with exposed drain paddle (pins 1–4 and 7–8 are drain), single gate (pin 5), and dual source terminals (pins 6 and 7). Package dimensions: 5.00 mm × 6.00 mm × 1.00 mm height, 1.27 mm pitch.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 7, 8	Drain (D)	High-current output node; electrically and thermally connected to exposed copper paddle
5	Gate (G)	Control input; requires ≤20 V drive; low 1.6 Ω series gate resistance minimizes ringing
6, 7	Source (S)	Power return path; dual-source layout reduces source inductance for high di/dt switching

Key Features

Feature	Design Value
Ultra-low R_DS(on)	1.0 mΩ @ 10 V enables <0.5% conduction loss in 12 V/100 A server VRMs
Low thermal resistance	0.8°C/W R_θJC allows direct mounting to heatsink without thermal interface material in compact modules
Avalanche rated	345 mJ single-pulse E_AS eliminates need for external snubbers in industrial motor drives
Logic-level gate	1.8 V V_GS(th) ensures full enhancement with 3.3 V FPGA I/O or digital PWM controllers
SON 5 mm × 6 mm package	Thermally optimized clip-bonded construction delivers 2× power density vs. SO-8 equivalents

Applications

Server Point-of-Load Converter	Industrial Motor Drive H-Bridge
Use Scenario: High-density 48 V–3.3 V/100 A VRM in AI accelerator cards requiring <1.5% voltage ripple and <85°C junction temperature. IC Role / Device Role / Timing Role: Primary high-side synchronous rectifier switch operating at 500 kHz with zero-voltage switching assist. Use Value: 1.0 mΩ R_DS(on) cuts conduction loss by 42% versus 1.7 mΩ alternatives, enabling 95.2% peak efficiency at full load.	Use Scenario: 24 V BLDC controller for factory automation actuators needing 30 A continuous phase current and stall protection. IC Role / Device Role / Timing Role: Low-side switch in three-phase inverter leg, commutated at 20 kHz with active freewheeling. Use Value: 345 mJ avalanche rating withstands 100 ms stall events without failure, eliminating external TVS clamping.
Telecom DC-DC Brick	Automotive ADAS Power Supply
Use Scenario: 54 V input, 12 V/40 A isolated forward converter in 1 RU telecom shelf with forced-air cooling. IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier, driven by transformer-coupled gate signal. Use Value: 17 nC Q_gd minimizes Miller-induced shoot-through risk during high dv/dt transitions (>10 V/ns).	Use Scenario: 12 V–5 V/15 A buck converter powering radar sensor SoCs in ambient temperatures up to 105°C. IC Role / Device Role / Timing Role: Main power switch operating in constant-on-time control mode with 2 MHz switching. Use Value: R_DS(on) increases only 1.4× from 25°C to 125°C (per Fig. 8), ensuring stable regulation across automotive temp range.

Server Point-of-Load Converter

Industrial Motor Drive H-Bridge

Use Scenario: High-density 48 V–3.3 V/100 A VRM in AI accelerator cards requiring <1.5% voltage ripple and <85°C junction temperature.

IC Role / Device Role / Timing Role: Primary high-side synchronous rectifier switch operating at 500 kHz with zero-voltage switching assist.

Use Value: 1.0 mΩ R_DS(on) cuts conduction loss by 42% versus 1.7 mΩ alternatives, enabling 95.2% peak efficiency at full load.

Use Scenario: 24 V BLDC controller for factory automation actuators needing 30 A continuous phase current and stall protection.

IC Role / Device Role / Timing Role: Low-side switch in three-phase inverter leg, commutated at 20 kHz with active freewheeling.

Use Value: 345 mJ avalanche rating withstands 100 ms stall events without failure, eliminating external TVS clamping.

Telecom DC-DC Brick

Automotive ADAS Power Supply

Use Scenario: 54 V input, 12 V/40 A isolated forward converter in 1 RU telecom shelf with forced-air cooling.

IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier, driven by transformer-coupled gate signal.

Use Value: 17 nC Q_gd minimizes Miller-induced shoot-through risk during high dv/dt transitions (>10 V/ns).

Use Scenario: 12 V–5 V/15 A buck converter powering radar sensor SoCs in ambient temperatures up to 105°C.

IC Role / Device Role / Timing Role: Main power switch operating in constant-on-time control mode with 2 MHz switching.

Use Value: R_DS(on) increases only 1.4× from 25°C to 125°C (per Fig. 8), ensuring stable regulation across automotive temp range.

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
IRLHS6342TRPBF	2.2 mΩ @ 4.5 V, 8-pin 3.3 mm × 3.3 mm PQFN, 60 V rating	Lower voltage rating and higher R_DS(on) limit use to ≤24 V systems with relaxed efficiency targets	Select when board space is constrained and 60 V blocking suffices for 24 V input rails
SiR626DP-T1-GE3	1.25 mΩ @ 10 V, 8-pin PowerPAK® SO-8, 40 V rating, 130 nC Q_g	Higher package thermal resistance (1.5°C/W) reduces max power handling by 45% at same PCB area	Choose when legacy SO-8 footprint compatibility is required and thermal headroom exists

Compared with CSD18509Q5BT, the IRLHS6342TRPBF trades off conduction loss and voltage margin for smaller size, while the SiR626DP-T1-GE3 retains matching voltage rating but sacrifices thermal performance due to SO-8 packaging-making CSD18509Q5BT optimal for space-constrained, thermally aggressive 40 V high-current applications.

Availability

CSD18509Q5BT is available at Aetrix Electronics and suitable for server power supplies, industrial motor drives, telecom DC-DC bricks, and automotive ADAS power systems requiring stable component supply and long-term production continuity.

Supply support for CSD18509Q5BT 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The CSD18509Q5BT belongs to TI's NexFET™ power MOSFET product line, engineered specifically for high-efficiency, high-current DC-DC conversion where ultra-low R_DS(on), low Q_g, and robust thermal performance are essential.

FAQ

What is the maximum continuous drain current rating for CSD18509Q5BT at 125°C case temperature?

The CSD18509Q5BT has a continuous drain current rating of 38 A at T_C = 125°C per its Absolute Maximum Ratings table. This derating reflects thermal limits under real-world heatsinking conditions-not silicon-limited capability-and aligns with the 100 A package-limited rating at 25°C case temperature. Engineers must verify PCB copper area and airflow to sustain this current in production.

Does CSD18509Q5BT support logic-level gate drive from a 3.3 V microcontroller?

Yes, CSD18509Q5BT supports logic-level gate drive from a 3.3 V microcontroller. Its typical gate threshold voltage is 1.8 V, and it achieves 1.3 mΩ R_DS(on) at V_GS = 4.5 V-well within the 3.3 V IO swing of most modern MCUs. However, full 1.0 mΩ performance requires 10 V drive, so system-level efficiency targets should guide gate driver selection for CSD18509Q5BT.

What is the recommended PCB pad layout for thermal management of CSD18509Q5BT?

The recommended PCB pad layout for CSD18509Q5BT uses a 1-inch² (6.45 cm²), 2-oz. copper thermal pad connected to internal ground planes via ≥8 thermal vias (0.3 mm diameter, 0.7 mm center-to-center spacing). TI's SLPA005 application note specifies exact stencil aperture dimensions (4.00 mm × 1.75 mm) and solder paste volume to ensure void-free solder joint formation on the exposed drain paddle-critical for achieving the specified 0.8°C/W R_θJC.

How does the avalanche rating of CSD18509Q5BT compare to standard MOSFETs without EAS specification?

CSD18509Q5BT is explicitly rated for 345 mJ single-pulse avalanche energy (I_D = 83 A, L = 0.1 mH, R_G = 25 Ω), unlike non-avalanche-rated MOSFETs that may fail catastrophically under similar unclamped inductive switching. This certified ruggedness allows CSD18509Q5BT to replace discrete snubber networks in motor drive half-bridges and flyback converters-reducing BOM count and improving reliability without sacrificing switching speed.

Is CSD18509Q5BT RoHS compliant and halogen free?

Yes, CSD18509Q5BT is RoHS exempt per TI's packaging addendum but fully compliant with JEDEC J-STD-609A Class 1 for lead-free finish (NiPdAu/Sn), and it is explicitly marked halogen-free in its official product summary. The "Halogen Free" feature bullet in the datasheet confirms brominated flame retardants and chlorine content are below IEC 61249-2-21 thresholds-meeting automotive and industrial environmental requirements without compromising package integrity.

CSD18509Q5BT Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: NexFET™

Package/Case:: 8-PowerTDFN

Packaging:: Tape & Reel (TR)

Product Status:: Active

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 40 V

Current - Continuous Drain (Id) @ 25°C:: 100A (Ta)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 1.2mOhm @ 32A, 10V

Vgs(th) (Max) @ Id:: 2.2V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 195 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 13900 pF @ 20 V

FET Feature:: -

Power Dissipation (Max):: 3.1W (Ta), 195W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-VSON-CLIP (5x6)

CSD18509Q5BT FAQ

1.How can I place an order for CSD18509Q5BT through Aetrix?

Please submit a Request for Quotation (RFQ) for CSD18509Q5BT 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 CSD18509Q5BT reliable?

The price and inventory of CSD18509Q5BT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CSD18509Q5BT is usually 5 days.

3.What payment methods are accepted for CSD18509Q5BT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CSD18509Q5BT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for CSD18509Q5BT?

CSD18509Q5BT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your CSD18509Q5BT 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 CSD18509Q5BT?

For technical support, including CSD18509Q5BT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CSD18509Q5BT requirements.

6.How does Aetrix verify that CSD18509Q5BT is sourced from the original manufacturer or authorized distributors?

All CSD18509Q5BT 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 CSD18509Q5BT meets industry standards.

7.What is the process for return or replacement of CSD18509Q5BT?

All CSD18509Q5BT units undergo pre-shipment inspection (PSI). If there is an issue with CSD18509Q5BT, 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 CSD18509Q5BT part is unused and in its original packaging.

Return procedure for CSD18509Q5BT:

1.Submit a request within 90 days.

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

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