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Nexperia USA Inc. BAS21W-QX
- Part No.:
- BAS21W-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BAS21W-QX.pdf
- Description:
- BAS21W-Q/SOT323/SC-70
- Quantity:
- Payment:
- Shipping:
Inventory:6,045
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Product details
Overview
BAS21W-Q from Nexperia is a high-voltage switching diode in SOT323 (SC-70) package, rated for 250 V reverse voltage, 225 mA forward current, and 50 ns reverse recovery time. It serves as a fast, low-leakage clamping and polarity protection device in automotive power rails and high-side switching circuits.
For engineers reviewing the BAS21W-Q datasheet, BAS21W-Q pinout, BAS21W-Q application, or BAS21W-Q equivalent, key selection criteria include reverse voltage margin at 250 V, sub-50 ns trr for high-frequency switching, AEC-Q101 qualification for automotive use, and SC-70 footprint compatibility with space-constrained PCB layouts.
Technical Context
This discrete silicon switching diode uses a planar epitaxial construction optimized for high-voltage blocking and rapid carrier recombination. Its 2 pF capacitance at 0 V and 100 nA leakage at 200 V/25 °C support stable operation in EMI-sensitive signal conditioning and flyback clamp paths.
The device operates across −55 °C to +150 °C junction temperature, with thermal resistance of 625 K/W (junction-to-ambient, free air) and 300 K/W (junction-to-solder point), enabling reliable performance in under-hood automotive modules without forced cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VR (Reverse Voltage) | 250 V - supports direct integration into 24 V and 48 V automotive systems with ≥2× safety margin over nominal bus voltage |
| trr (Reverse Recovery Time) | 50 ns - enables clean turn-off in PWM-driven inductive loads up to ~2 MHz switching frequency |
| IF (Forward Current) | 225 mA continuous - sufficient for biasing, level-shifting, and low-power protection functions in sensor interfaces |
| IR (Reverse Leakage) | 100 nA at 200 V/25 °C - ensures minimal standby power loss in always-on vehicle subsystems |
| Cd (Diode Capacitance) | 2 pF at 0 V/1 MHz - preserves signal integrity in high-speed data line clamping and RF detector applications |
| Ptot (Power Dissipation) | 200 mW at Tamb ≤ 25 °C - defines thermal derating curve for FR4 PCB mounting without heatsinking |
Pinout & Package
Package: SOT323 (SC-70), 3-lead surface-mount plastic package measuring 2.0 mm × 1.25 mm × 0.95 mm with 1.3 mm lead pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Forward current entry point; connects to higher-potential node in clamping or rectification path |
| 2 | Not Connected (n.c.) | Internally isolated; must remain unconnected on PCB to avoid parasitic coupling or mechanical stress |
| 3 | Cathode (K) | Forward current exit and reverse-blocking terminal; ties to ground or return rail in protection circuits |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD per JESD22 standards |
| Low trr ≤ 50 ns | Reduces switching losses and voltage overshoot in flyback snubbers and DC-DC converter freewheel paths |
| High VR = 250 V | Enables single-diode solutions in 24 V battery systems with load-dump transients up to 120 V |
| Ultra-small SOT323 footprint | Supports dense routing in ADAS camera modules and body control unit PCBs with <2.5 mm² board area |
Applications
| Automotive Load-Dump Protection | High-Speed Signal Clamping |
|---|---|
Use Scenario: Suppresses ISO 7637-2 Pulse 5a transients (up to 120 V, 100 ms) on 12 V/24 V vehicle power lines. IC Role / Device Role / Timing Role: Fast-switching clamping diode placed between supply rail and ground to shunt surge energy before downstream regulators. Use Value: 250 V VR rating provides 100 % margin above worst-case load-dump peak, while 50 ns trr prevents latch-up during repetitive pulses. | Use Scenario: Limits voltage excursions on UART, LIN, or CAN physical layer lines exposed to ESD or inductive coupling. IC Role / Device Role / Timing Role: Bidirectional transient voltage suppressor connected between signal line and reference rail. Use Value: 2 pF capacitance avoids signal degradation at >1 Mbps data rates; 100 nA leakage preserves logic thresholds in battery-powered nodes. |
| Reverse Polarity Input Protection | High-Voltage Flyback Snubber |
Use Scenario: Prevents damage when external power adapters or jump-start cables are connected with reversed polarity to infotainment head units. IC Role / Device Role / Timing Role: Series-connected anode-to-input switch that blocks reverse current flow while passing forward current with <1.25 V VF drop. Use Value: 225 mA IF rating handles typical 5–12 V/100–200 mA system inputs; AEC-Q101 qualification ensures longevity in field deployments. | Use Scenario: Absorbs leakage inductance energy in 24 V offline flyback converters used in LED driver modules. IC Role / Device Role / Timing Role: Clamp diode across primary winding to limit MOSFET drain voltage spikes during turn-off. Use Value: 50 ns trr ensures full energy transfer before secondary conduction begins; 250 V VR withstands reflected output voltage plus leakage spike. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor MMBD2102LT1G | 200 V VR, 200 mA IF, 50 ns trr, same SOT-323 package | Lower reverse voltage margin; suitable only for 12 V systems with <100 V transients | Select when cost sensitivity outweighs need for 250 V headroom in non-automotive designs |
| Vishay BAV21W | 250 V VR, 250 mA IF, 50 ns trr, SOD-123 package (larger footprint) | Higher IF rating but incompatible with SC-70 layout; requires PCB redesign | Choose if thermal dissipation >200 mW is required and board space allows SOD-123 placement |
Compared with MMBD2102LT1G and BAV21W, the BAS21W-Q uniquely combines AEC-Q101 qualification, 250 V rating, and SOT323 size-making it the only option for space-constrained, automotive-compliant high-voltage switching where both reliability and miniaturization are mandatory.
Availability
BAS21W-Q is available at Aetrix Electronics and suitable for automotive load-dump protection, reverse polarity input protection, and high-voltage flyback snubber circuits requiring stable component supply and long-term lifecycle assurance.
Supply support for BAS21W-Q 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
Nexperia is a global semiconductor expert specializing in high-performance, high-reliability discrete and logic devices, with leadership in automotive-qualified components and advanced packaging.
The BAS21W-Q belongs to Nexperia's AEC-Q101-qualified high-voltage diode product line, engineered specifically for robust transient suppression and polarity protection in automotive power distribution networks.
FAQ
Is BAS21W-Q suitable for 48 V mild-hybrid vehicle systems?
Yes. With a 250 V reverse voltage rating and AEC-Q101 qualification, the BAS21W-Q supports 48 V systems including load-dump transients up to 120 V. Its 225 mA forward current and 50 ns trr meet requirements for auxiliary power rail protection and gate drive clamping in 48 V DC-DC converters.
What is the maximum ambient temperature for continuous operation on FR4 PCB?
At 25 °C ambient, the device dissipates up to 200 mW. Derating follows a linear curve: maximum ambient temperature drops to 100 °C at 100 mW and 50 °C at 150 mW. Full 225 mA operation is limited to Tamb ≤ 75 °C on standard FR4 with single-sided copper.
Can Pin 2 (n.c.) be grounded or left floating on the PCB?
Pin 2 is internally not connected and must remain unconnected on the PCB. Grounding or routing to any net introduces risk of mechanical stress fracture, solder wicking, or parasitic coupling. The recommended footprint (Fig. 8) specifies a 0.5 mm solder pad with no copper trace attached.
How does BAS21W-Q compare to standard BAS21 in automotive use?
The BAS21W-Q adds AEC-Q101 qualification, tighter parameter screening (e.g., guaranteed trr ≤ 50 ns), and extended temperature validation (−55 °C to +150 °C). Standard BAS21 lacks automotive qualification and may exhibit wider parametric spread, making BAS21W-Q mandatory for production automotive ECUs.
BAS21W-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 250 V
- Current - Average Rectified (Io):
- 225mA
- Voltage - Forward (Vf) (Max) @ If:
- 1.25 V @ 200 mA
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 50 ns
- Current - Reverse Leakage @ Vr:
- 100 nA @ 200 V
- Capacitance @ Vr, F:
- 2pF @ 0V, 1MHz
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
- Operating Temperature - Junction:
- 150°C
BAS21W-QX FAQ
1.How can I place an order for BAS21W-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BAS21W-QX 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 BAS21W-QX reliable?
The price and inventory of BAS21W-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS21W-QX is usually 5 days.
3.What payment methods are accepted for BAS21W-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS21W-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BAS21W-QX?
BAS21W-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BAS21W-QX 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 BAS21W-QX?
For technical support, including BAS21W-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS21W-QX requirements.
6.How does Aetrix verify that BAS21W-QX is sourced from the original manufacturer or authorized distributors?
All BAS21W-QX 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 BAS21W-QX meets industry standards.
7.What is the process for return or replacement of BAS21W-QX?
All BAS21W-QX units undergo pre-shipment inspection (PSI). If there is an issue with BAS21W-QX, 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 BAS21W-QX part is unused and in its original packaging.
Return procedure for BAS21W-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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