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Taiwan Semiconductor Corporation BAS21 RFG
- Part No.:
- BAS21 RFG
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BAS21 RFG.pdf
- Description:
- DIODE GEN PURP 250V 200MA SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:11,478
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Product details
Overview
BAS21 RFG from Taiwan Semiconductor is a 200 mA, 250 V SMD switching diode in SOT-23 package, featuring 1.25 V forward voltage at 200 mA, 50 ns reverse recovery time, and 1 A non-repetitive surge current-used in high-efficiency SMPS secondary-side rectification and fast-switching signal path clamping.
For engineers reviewing the BAS21 RFG datasheet, BAS21 RFG pinout, BAS21 RFG application, or BAS21 RFG equivalent, key selection criteria include reverse recovery time (trr ≤ 50 ns), repetitive peak reverse voltage (VRRM = 250 V), junction temperature range (–55°C to +150°C), and RoHS/halogen-free compliance for industrial power designs.
Technical Context
This silicon planar epitaxial switching diode uses a low-capacitance (CJ ≤ 5 pF @ 1 MHz, 1 V) structure optimized for high-speed turn-off in DC-DC converters and flyback snubbers. Its 500°C/W junction-to-ambient thermal resistance and 225 mW power dissipation support operation up to 150°C junction temperature under defined PCB copper area.
The device meets JESD201 Class 1A whisker resistance and J-STD-020 Level 1 moisture sensitivity-enabling direct use in reflow soldering without baking. Terminal plating is matte tin, compliant with J-STD-002 for reliable solderability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| IF (Continuous Forward Current) | 200 mA - supports sustained conduction in auxiliary bias rails and low-power gate drive circuits |
| VRRM (Repetitive Peak Reverse Voltage) | 250 V - enables use in 110/220 VAC-input SMPS output stages and clamp networks |
| trr (Reverse Recovery Time) | 50 ns - minimizes switching loss and EMI in >100 kHz DC-DC topologies |
| VF @ IF=200mA | 1.25 V - defines forward conduction loss at rated current; impacts efficiency in low-voltage secondary windings |
| TJ max | +150°C - allows operation in thermally constrained enclosed power modules without derating |
| CJ @ 1 MHz, 1 V | 5 pF - limits capacitive loading in high-frequency signal routing and timing circuits |
Pinout & Package
Package: SOT-23 - surface-mount, 3-terminal plastic package with standard JEDEC MO-215 outline; 8 ± 0.5 mg weight; UL 94 V-0 molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward current entry point | Connected to higher-potential node during conduction; requires trace width sizing for 200 mA continuous |
| Cathode (Pin 2) | Forward current exit / reverse blocking terminal | Common reference for clamp or freewheeling paths; ties to ground or return rail in flyback snubbers |
| No-Connect (Pin 3) | Internal die attach pad (non-functional) | Thermally conductive but electrically isolated; may be grounded for thermal relief if PCB layout permits |
Key Features
| Feature | Design Value |
|---|---|
| Low forward voltage drop | VF = 1.25 V @ 200 mA ensures <250 mW conduction loss in compact SMPS outputs |
| Fast reverse recovery | trr ≤ 50 ns reduces switching transition overlap loss in hard-switched converters |
| High surge capability | IFSM = 1 A (8.3 ms) withstands inrush and transient overloads in AC-DC front ends |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS 2011/65/EU for environmentally regulated industrial shipments |
Applications
| SMPS Secondary Rectification | Flyback Snubber Clamping |
|---|---|
Use Scenario: Rectifying secondary-side output in 12–24 V, 5–10 W offline flyback converters. IC Role / Device Role / Timing Role: Fast-switching unidirectional current valve enabling efficient energy transfer during transformer reset phase. Use Value: 50 ns trr and 250 V VRRM allow stable operation at 65–100 kHz with minimal switching loss and voltage overshoot. | Use Scenario: Clamping voltage spikes across primary MOSFETs in discontinuous conduction mode (DCM) flyback designs. IC Role / Device Role / Timing Role: Transient voltage suppressor that conducts only during MOSFET turn-off edge to absorb leakage inductance energy. Use Value: 1 A IFSM and 250 V VRRM handle repetitive 300–400 V spikes without degradation over 10+ year service life. |
| Signal-Level Clamping | Logic-Level Protection Diode |
Use Scenario: Protecting microcontroller GPIO pins from external 5 V or 3.3 V signal transients in industrial I/O modules. IC Role / Device Role / Timing Role: Low-capacitance (5 pF) shunt limiter limiting input voltage to safe levels during ESD or inductive kick events. Use Value: CJ ≤ 5 pF avoids signal integrity degradation on lines operating up to 100 MHz, while VF < 1.25 V ensures clean logic thresholds. | Use Scenario: Isolating parallel MCU outputs driving shared LED or relay loads in programmable logic controllers. IC Role / Device Role / Timing Role: Blocking diode preventing backfeed between adjacent output channels during state transitions. Use Value: 200 mA IF rating supports direct connection to 20 mA per-channel LED banks; SOT-23 footprint enables dense board layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor BAS21DW-7-F | Dual-diode SOT-363 package; same VRRM/trr/IF specs but dual configuration | Used where space-constrained dual-path clamping or redundancy is required | Select when needing two matched diodes in one footprint; not pin-compatible with single SOT-23 BAS21 RFG |
| Diodes Incorporated BAV21W-7-F | Identical VRRM (250 V), trr (50 ns), IF (200 mA); slightly higher VF (1.3 V @ 200 mA) | Same SMPS and clamping roles; validated in automotive-grade AEC-Q200 stress tests | Choose for AEC-Q200-compliant designs; otherwise functionally interchangeable in industrial applications |
Compared with BAS21 RFG, BAS21DW-7-F offers dual-diode integration at the cost of layout flexibility, while BAV21W-7-F provides automotive qualification with negligible VF trade-off-both require schematic and placement review but no electrical redesign.
Availability
BAS21 RFG is available at Aetrix Electronics and suitable for switching mode power supplies, flyback snubber networks, signal-level clamping circuits, and logic-level isolation requiring stable component supply and full halogen-free compliance.
Supply support for BAS21 RFG 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving industrial, computing, and consumer markets since 1979.
The BAS21 series belongs to TSC's general-purpose high-speed switching diode product line, engineered specifically for efficiency-critical, high-frequency power conversion and protection functions in compact SMT power systems.
FAQ
What is the maximum junction temperature rating for BAS21 RFG?
The BAS21 RFG has a specified junction temperature range of –55°C to +150°C. This allows reliable operation in enclosed power supplies and industrial environments where ambient temperatures exceed 85°C. Derating of power dissipation begins above 25°C ambient per the admissible power dissipation curve in the datasheet, and the 150°C TJ max ensures long-term stability under sustained load conditions in the BAS21 RFG.
Is BAS21 RFG RoHS and halogen-free compliant?
Yes, BAS21 RFG is both RoHS compliant per EU Directive 2011/65/EU and halogen-free according to IEC 61249-2-21. The "G" suffix in BAS21 RFG explicitly denotes green compound packaging. This makes the BAS21 RFG suitable for export-controlled and environmentally regulated industrial equipment where material declarations are mandatory.
What is the reverse recovery time (trr) of BAS21 RFG and how is it measured?
The BAS21 RFG has a reverse recovery time (trr) of 50 ns, measured under conditions of IF = IR = 30 mA, RL = 100 Ω, and IRR = 1 mA. This value reflects the diode's speed in transitioning from forward conduction to reverse blocking-critical for minimizing switching losses in high-frequency SMPS. The trr specification applies directly to the BAS21 RFG and is verified per JEDEC test methods.
Does BAS21 RFG have a moisture sensitivity level (MSL) rating?
Yes, BAS21 RFG is rated MSL Level 1 per J-STD-020, meaning it can be stored indefinitely at ≤30°C/60% RH and is compatible with standard lead-free reflow profiles without pre-baking. This simplifies manufacturing logistics and eliminates moisture-related popcorning risk during assembly-confirming the BAS21 RFG's suitability for high-volume SMT production.
What is the marking code for BAS21 RFG on the device body?
The marking code for BAS21 RFG is "JS" on the top surface of the SOT-23 package. This 2-character laser mark identifies the BAS21 variant within the BAS21/A/C/S family and is consistent across all Taiwan Semiconductor production lots of the BAS21 RFG. Visual inspection of "JS" confirms correct variant identity during incoming quality checks.
BAS21 RFG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 250 V
- Current - Average Rectified (Io):
- 200mA
- Voltage - Forward (Vf) (Max) @ If:
- 1.25 V @ 200 mA
- Speed:
- Small Signal =< 200mA (Io), Any Speed
- Reverse Recovery Time (trr):
- 50 ns
- Current - Reverse Leakage @ Vr:
- 100 nA @ 200 V
- Capacitance @ Vr, F:
- 5pF @ 1V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23
- Operating Temperature - Junction:
- -55°C ~ 150°C
BAS21 RFG FAQ
1.How can I place an order for BAS21 RFG through Aetrix?
Please submit a Request for Quotation (RFQ) for BAS21 RFG 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 BAS21 RFG reliable?
The price and inventory of BAS21 RFG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS21 RFG is usually 5 days.
3.What payment methods are accepted for BAS21 RFG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS21 RFG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BAS21 RFG?
BAS21 RFG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BAS21 RFG 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 BAS21 RFG?
For technical support, including BAS21 RFG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS21 RFG requirements.
6.How does Aetrix verify that BAS21 RFG is sourced from the original manufacturer or authorized distributors?
All BAS21 RFG 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 BAS21 RFG meets industry standards.
7.What is the process for return or replacement of BAS21 RFG?
All BAS21 RFG units undergo pre-shipment inspection (PSI). If there is an issue with BAS21 RFG, 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 BAS21 RFG part is unused and in its original packaging.
Return procedure for BAS21 RFG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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