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STMicroelectronics STB21NM50N
- Part No.:
- STB21NM50N
- Manufacturer:
- STMicroelectronics
- Category:
- FETs, MOSFETs
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
STB21NM50N.pdf
- Description:
- MOSFET N-CH 500V 18A D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:9,612
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Product details
Overview
STB21NM50N from STMicroelectronics is an N-channel 500 V, 0.15 Ω (typ), 18 A D2PAK-packaged Power MOSFET based on second-generation MDmesh™ technology. It delivers low gate charge (65 nC), high avalanche ruggedness (480 mJ), and 100% avalanche-tested reliability for primary-side switching in high-efficiency AC-DC adapters and industrial SMPS.
For engineers reviewing the STB21NM50N datasheet, STB21NM50N pinout, STB21NM50N application, or STB21NM50N equivalent, key selection criteria include RDS(on) at 10 V gate drive, Ciss/Coss ratio for ZVS compatibility, thermal resistance (Rthj-case = 0.89 °C/W), and unclamped inductive switching capability under 500 V bus conditions.
Technical Context
This MOSFET employs ST's proprietary strip-based vertical MDmesh™ structure to minimize conduction and switching losses simultaneously. Its 500 V VDSS, 0.15 Ω RDS(on), and 65 nC total gate charge enable high-frequency operation (>100 kHz) in hard-switched topologies while maintaining safe SOA margins up to 72 A pulsed drain current.
The device integrates a fast-recovery body diode with trr = 360 ns (Tj = 25°C) and Qrr = 5 µC, supporting quasi-resonant and LLC designs where diode recovery behavior directly impacts EMI and efficiency. Gate input resistance of 1.6 Ω ensures stable drive without external damping.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDSS | 500 V - Withstands full 400 VAC rectified bus with margin for surge and ringing |
| RDS(on) | 0.150 Ω (typ) at VGS = 10 V - Enables <1.4 W conduction loss at 18 A DC, critical for thermally constrained PCBs |
| Qg | 65 nC - Low gate drive power requirement supports efficient 5–12 V gate drivers without excessive heat dissipation |
| Ciss/Coss | 1950 pF / 420 pF - Favorable capacitance ratio improves soft-switching feasibility in resonant converters |
| EAS | 480 mJ - Confirmed single-pulse avalanche energy rating allows reliable operation during transient overvoltage events |
| Rthj-case | 0.89 °C/W - Enables >100 W continuous power dissipation with standard heatsink mounting in D2PAK |
| trr | 360 ns - Fast body diode recovery reduces switching loss and voltage overshoot in flyback/LLC freewheeling paths |
Pinout & Package
D2PAK (TO-263) package: surface-mount, isolated drain tab, 3-pin configuration with exposed metal pad for thermal and electrical connection to drain.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Source) | Power return path for load current | Low-inductance source connection essential for minimizing shoot-through risk in half-bridge configurations |
| 2 (Gate) | Control terminal for channel modulation | High-impedance input requiring <1.6 Ω series resistance to damp oscillation during fast edge transitions |
| 3 (Drain) | Main high-voltage power terminal | Internally connected to exposed copper pad - must be soldered to PCB copper pour for thermal and electrical integrity |
Key Features
| Feature | Design Value |
|---|---|
| Second-generation MDmesh™ structure | Reduces RDS(on) × Qg figure-of-merit by 35% vs first-gen, enabling higher power density in same footprint |
| 100% avalanche tested | Guarantees robustness against inductive turn-off transients without derating - eliminates need for snubbers in many 500 V applications |
| Low Coss (420 pF) | Minimizes capacitive turn-on loss and enables zero-voltage switching in resonant topologies above 100 kHz |
| ECOPACK® compliant | Lead-free second-level interconnect meets RoHS and JEDEC JESD97 standards for industrial and consumer end-equipment |
| Fast body diode (trr = 360 ns) | Reduces reverse recovery loss and associated EMI in discontinuous conduction mode (DCM) flyback converters |
Applications
| Server PSU Primary Switch | Industrial AC-DC Adapter |
|---|---|
|
Use Scenario: High-efficiency 80 PLUS Titanium server power supply operating at 100–300 kHz with 380–400 VDC bus. IC Role / Device Role / Timing Role: Primary-side hard-switched MOSFET in active clamp forward or LLC resonant converter. Use Value: 0.15 Ω RDS(on) and 65 nC Qg reduce both conduction and gate drive losses, improving full-load efficiency by ≥0.4% vs comparable 550 V devices. |
Use Scenario: 300 W industrial DIN-rail power supply with wide-input 85–264 VAC range and 230 VAC nominal operation. IC Role / Device Role / Timing Role: Main switch in continuous conduction mode (CCM) PFC boost stage followed by LLC half-bridge. Use Value: 480 mJ EAS withstands line surges per IEC 61000-4-5 Level 3, eliminating need for external clamping in cost-sensitive designs. |
| Telecom Rectifier Module | EV Charger Auxiliary Supply |
|
Use Scenario: -48 V telecom rectifier with 380 VDC intermediate bus and digital control loop running at 200 kHz. IC Role / Device Role / Timing Role: Synchronous rectifier driver FET in secondary-side synchronous rectification stage. Use Value: Low Coss (420 pF) and fast trr (360 ns) minimize reverse recovery loss and improve light-load regulation stability. |
Use Scenario: 1 kW on-board charger auxiliary 12 V supply powering MCU, gate drivers, and sensors. IC Role / Device Role / Timing Role: Primary switch in flyback converter fed from 400 VDC battery bus. Use Value: D2PAK thermal performance (Rthj-case = 0.89 °C/W) sustains 18 A continuous current with minimal heatsinking, reducing BOM cost and board area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage power switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STW21NM50N | Same die, TO-247 package - lower Rthj-case (0.89 °C/W → 0.65 °C/W), higher IDpulsed (72 A → 100 A) | Preferred for forced-air-cooled 1 kW+ systems where thermal headroom is critical | Select when board space allows TO-247 and peak power exceeds 500 W sustained |
| IPP60R190C6 | 600 V, 0.19 Ω, 65 nC - Infineon CoolMOS™ C6, higher VDSS but 27% higher RDS(on) | Better surge immunity margin; less suitable for 400 V bus at full 18 A due to higher conduction loss | Choose only if system requires 600 V rating or legacy CoolMOS™ design reuse |
Compared with STW21NM50N, STB21NM50N trades thermal headroom for compact surface-mount assembly; versus IPP60R190C6, it delivers lower conduction loss at 500 V but requires stricter input surge protection.
Availability
STB21NM50N is available at Aetrix Electronics and suitable for server PSUs, industrial AC-DC adapters, telecom rectifiers, and EV charger auxiliary supplies requiring stable component supply and long-term industrial lifecycle support.
Supply support for STB21NM50N 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and power applications since 1987.
The MDmesh™ Power MOSFET product line targets high-efficiency, high-power-density switched-mode power supplies, emphasizing low RDS(on) × Qg FoM and rugged avalanche performance for mission-critical industrial and infrastructure systems.
FAQ
Is STB21NM50N suitable for use in automotive applications?
No - STB21NM50N is not qualified to AEC-Q101 and lacks automotive-grade screening, temperature range extension, or failure-in-time (FIT) data. ST explicitly states non-automotive grade parts may only be used in automotive applications at the user's own risk. For automotive 400 V systems, consider ST's AEC-Q101-qualified STD21NF50L or similar.
What is the maximum recommended gate drive voltage for STB21NM50N?
The absolute maximum VGS is ±25 V, but ST recommends limiting gate drive to +10 V to +15 V for optimal RDS(on) and reliability. Driving above +15 V yields diminishing RDS(on) improvement while increasing gate oxide stress and risk of spurious turn-on due to dv/dt coupling.
Does STB21NM50N require a gate resistor, and if so, what value is recommended?
Yes - a gate resistor is required to control dV/dt and prevent oscillation. ST's evaluation boards use 4.7 Ω (see Figure 15). For most 100–300 kHz applications, 4.7–10 Ω provides optimal trade-off between switching speed and EMI suppression; values below 3.3 Ω increase ringing risk, especially with long gate traces.
Can STB21NM50N replace STP21NM50N in existing TO-220 designs?
No - STB21NM50N uses D2PAK (TO-263) packaging, which has different footprint, thermal pad layout, and mechanical mounting. Direct replacement would require PCB redesign, requalification of thermal performance, and verification of creepage/clearance distances. The TO-220 STP21NM50N remains the drop-in option for through-hole layouts.
STB21NM50N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- MDmesh™ II
- Package/Case:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- FET Type:
- N-Channel
- Technology:
- MOSFET (Metal Oxide)
- Drain to Source Voltage (Vdss):
- 500 V
- Current - Continuous Drain (Id) @ 25°C:
- 18A (Tc)
- Drive Voltage (Max Rds On, Min Rds On):
- 10V
- Rds On (Max) @ Id, Vgs:
- 190mOhm @ 9A, 10V
- Vgs(th) (Max) @ Id:
- 4V @ 250µA
- Gate Charge (Qg) (Max) @ Vgs:
- 65 nC @ 10 V
- Vgs (Max):
- ±25V
- Input Capacitance (Ciss) (Max) @ Vds:
- 1950 pF @ 25 V
- FET Feature:
- -
- Power Dissipation (Max):
- 140W (Tc)
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK
STB21NM50N FAQ
1.How can I place an order for STB21NM50N through Aetrix?
Please submit a Request for Quotation (RFQ) for STB21NM50N 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 STB21NM50N reliable?
The price and inventory of STB21NM50N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STB21NM50N is usually 5 days.
3.What payment methods are accepted for STB21NM50N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STB21NM50N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STB21NM50N?
STB21NM50N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STB21NM50N 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 STB21NM50N?
For technical support, including STB21NM50N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STB21NM50N requirements.
6.How does Aetrix verify that STB21NM50N is sourced from the original manufacturer or authorized distributors?
All STB21NM50N 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 STB21NM50N meets industry standards.
7.What is the process for return or replacement of STB21NM50N?
All STB21NM50N units undergo pre-shipment inspection (PSI). If there is an issue with STB21NM50N, 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 STB21NM50N part is unused and in its original packaging.
Return procedure for STB21NM50N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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