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Diodes Incorporated BAS521LP-7B
- Part No.:
- BAS521LP-7B
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Diodes
- Package:
- 0402 (1006 Metric)
- Datasheet:
-
BAS521LP-7B.pdf
- Description:
- DIODE GEN PURP 325V 400MA 2DFN
- Quantity:
- Payment:
- Shipping:
Inventory:6,364
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Product details
Overview
BAS521LP-7B from Diodes Incorporated is a high-voltage, fast-switching silicon switching diode in a 2-terminal DFN1006 package. It delivers 325V repetitive peak reverse voltage, 50ns reverse recovery time, and 400mA forward current capability, enabling reliable operation in high-speed flyback snubbers and DC-DC converter clamp circuits.
For engineers reviewing the BAS521LP-7B datasheet, BAS521LP-7B pinout, BAS521LP-7B application, or BAS521LP-7B equivalent, key selection criteria include reverse breakdown margin at elevated temperature, low leakage under high VR bias, ultra-small footprint for space-constrained power stages, and compatibility with automated SMT assembly on FR-4 PCBs.
Technical Context
This diode operates as a unidirectional, surface-mount switching element optimized for high-voltage transient suppression and energy recycling in switching power supplies. Its 325V VRRM rating supports 230VAC input-derived rails, while the 50ns trr ensures minimal switching loss during turn-off in 100–500kHz converters.
The X1-DFN1006-2 package integrates NiPdAu-plated copper terminals and UL 94V-0 molding compound, supporting reflow soldering per MIL-STD-202 and achieving 312°C/W junction-to-ambient thermal resistance on standard FR-4 layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 325V - Withstands peak reverse transients in universal-input offline SMPS without avalanche conduction |
| trr | 50ns max - Enables efficient operation up to 500kHz switching frequency with low turn-off loss |
| IF | 400mA continuous - Supports moderate-current clamp and freewheel paths in auxiliary windings |
| IR @ VR=250V | 150nA max - Ensures negligible leakage-induced power loss in high-impedance bias networks |
| CT | 5pF @ 0V - Minimizes capacitive loading on high-frequency gate drive or feedback nodes |
| PD | 400mW - Delivers usable power handling within thermal limits of 1.0mm × 0.6mm footprint |
Pinout & Package
Package: X1-DFN1006-2 (1.0mm × 0.6mm × 0.5mm), ultra-compact leadless plastic case with cathode-marked top surface and NiPdAu-plated copper terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Forward current entry point | Connected to switch node or inductive load return path; requires thermal pad connection for power dissipation |
| 2 (Cathode) | Forward current exit / reverse blocking terminal | Marked by bar or dot on top surface; ties to higher-potential rail or output capacitor positive |
Key Features
| Feature | Design Value |
|---|---|
| High VRRM / small size ratio | 325V in 0.6mm² footprint - Enables compact high-voltage clamping where TO-236 or SOD-323 are too large |
| Low trr with stable IR | 50ns recovery with ≤150nA leakage at 250V - Reduces switching loss without compromising blocking integrity |
| Lead-free & halogen-free construction | RoHS 2 compliant, <900ppm Br+Cl, <1000ppm Sb - Meets automotive and industrial environmental compliance mandates |
| Moisture sensitivity level | MSL Level 1 - Eliminates bake requirements prior to reflow, simplifying manufacturing flow |
Applications
| AC-DC Adapter Clamp Circuit | USB-C PD Flyback Snubber |
|---|---|
Use Scenario: Clamps voltage spikes across primary-side MOSFET in 12–65W offline flyback adapters. IC Role / Device Role: Fast-recovery snubber diode placed between drain and auxiliary winding. Use Value: 325V VRRM provides 25% margin over 264VAC-derived peaks; 50ns trr prevents snap-off oscillation. | Use Scenario: Absorbs leakage inductance energy in 100W USB-C PD flyback converters operating at 200kHz. IC Role / Device Role: Secondary-side clamp diode in RCD network tied to transformer auxiliary winding. Use Value: 5pF capacitance avoids resonance with snubber resistor; 150nA IR at 250V minimizes standby loss. |
| Industrial PLC Input Protection | Smart Meter Voltage Monitor Clamp |
Use Scenario: Protects 24VDC digital input channels against 400V surge transients per IEC 61000-4-5. IC Role / Device Role: High-voltage transient suppressor in series with input RC filter. Use Value: 325V VRRM withstands repeated 350V surges; MSL Level 1 enables direct placement on production line. | Use Scenario: Clamps induced transients on AC voltage sensing inputs in Class 0.5 smart meters. IC Role / Device Role: Front-end protection diode in resistive divider network feeding ADC reference. Use Value: 50nA IR at 5V ensures <0.1% measurement error in high-impedance dividers; 1.0mm × 0.6mm saves board area near meter SoC. |
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 |
|---|---|---|---|
| BAS21-7-F | Higher VRRM (250V), larger SOT-23 package (2.9mm × 1.3mm), 50ns trr | Less suitable for ultra-dense layouts; higher thermal resistance (350°C/W) | Select when legacy SMT lines lack DFN1006 tooling or when higher surge robustness is required |
| 1N4148W-7-F | Lower VRRM (100V), same DFN1006 package, 4ns trr | Insufficient for >150V applications; faster but lower voltage tolerance | Choose only for low-voltage signal switching where speed dominates voltage margin |
Compared with BAS21-7-F and 1N4148W-7-F, the BAS521LP-7B uniquely balances 325V blocking, 50ns recovery, and 1.0mm × 0.6mm footprint-making it optimal for next-generation compact, high-efficiency AC-DC and industrial power interfaces.
Availability
BAS521LP-7B is available at Aetrix Electronics and suitable for AC-DC adapter design, USB-C PD power supply development, and industrial PLC input protection requiring stable component supply and long-term lifecycle assurance.
Supply support for BAS521LP-7B 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.
The BAS521LP belongs to Diodes' high-voltage switching diode product line, engineered specifically for compact, high-efficiency power conversion and transient protection in space-constrained industrial and consumer power systems.
FAQ
What is the maximum junction temperature for continuous operation?
The BAS521LP-7B supports continuous operation from –65°C to +150°C junction temperature. At 150°C, its reverse leakage rises to 100µA at VR = 250V, which must be accounted for in thermal design. Derating begins above 25°C ambient, with full 400mW power dissipation only permissible below 25°C ambient on recommended FR-4 pad layout.
Is the BAS521LP-7B suitable for use in automotive applications?
The BAS521LP-7B is not AEC-Q200 qualified and lacks automotive-specific qualification testing. While its –65°C to +150°C operating range meets automotive ambient requirements, Diodes does not guarantee performance under automotive stress conditions such as extended temperature cycling or board-level vibration. It may be used in non-safety-critical aftermarket or infotainment subsystems with customer validation.
How does the DFN1006 package affect solder joint reliability?
The X1-DFN1006-2 package uses NiPdAu-plated copper leads and is rated MSL Level 1, eliminating moisture-related popcorning risk. Its symmetric 2-pad layout and low mass (0.0009g) reduce thermal stress during reflow. However, mechanical anchoring relies solely on solder adhesion-no exposed thermal pad-so IPC-A-610 Class 2/3 process control is essential to prevent tombstoning or voiding.
Can BAS521LP-7B replace BAS16 in existing designs?
No-BAS16 has 100V VRRM and SOT-23 package, making it incompatible with BAS521LP-7B's 325V rating and DFN1006 footprint. Direct replacement would require PCB redesign and verification of voltage margin, thermal performance, and EMI behavior due to differing parasitic capacitance (5pF vs ~2pF) and layout geometry.
BAS521LP-7B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 0402 (1006 Metric)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 325 V
- Current - Average Rectified (Io):
- 400mA
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 100 mA
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 50 ns
- Current - Reverse Leakage @ Vr:
- 150 nA @ 250 V
- Capacitance @ Vr, F:
- 5pF @ 0V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- X1-DFN1006-2
- Operating Temperature - Junction:
- -65°C ~ 150°C
BAS521LP-7B FAQ
1.How can I place an order for BAS521LP-7B through Aetrix?
Please submit a Request for Quotation (RFQ) for BAS521LP-7B 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 BAS521LP-7B reliable?
The price and inventory of BAS521LP-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS521LP-7B is usually 5 days.
3.What payment methods are accepted for BAS521LP-7B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS521LP-7B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BAS521LP-7B?
BAS521LP-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BAS521LP-7B 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 BAS521LP-7B?
For technical support, including BAS521LP-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS521LP-7B requirements.
6.How does Aetrix verify that BAS521LP-7B is sourced from the original manufacturer or authorized distributors?
All BAS521LP-7B 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 BAS521LP-7B meets industry standards.
7.What is the process for return or replacement of BAS521LP-7B?
All BAS521LP-7B units undergo pre-shipment inspection (PSI). If there is an issue with BAS521LP-7B, 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 BAS521LP-7B part is unused and in its original packaging.
Return procedure for BAS521LP-7B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BAS521LP-7B Tags
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1N4448X-TP
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1N4148WX-TP
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1N4148TR
onsemi
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MMSD4148T1G
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BAS16HT1G
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1N914BWT
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BAS21LT1G
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LL4148
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BAS16LT1G
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MMSD914T1G
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BAV21W-7-F
Diodes Incorporated
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