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Diodes Incorporated HER305-T
- Part No.:
- HER305-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Diodes
- Package:
- DO-201AD, Axial
- Datasheet:
-
HER305-T.pdf
- Description:
- DIODE GEN PURP 400V 3A DO201AD
- Quantity:
- Payment:
- Shipping:
Inventory:4,412
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Product details
Overview
HER305-T from Diodes Incorporated is a 3.0A high-efficiency axial-lead rectifier diode with 400V maximum recurrent peak reverse voltage (VRRM), 1.1V forward voltage at 3.0A, and 50ns reverse recovery time - designed for AC/DC input stage rectification in offline power supplies and switch-mode adapters.
For engineers reviewing the HER305-T datasheet, HER305-T pinout, HER305-T application, or HER305-T equivalent, key selection criteria include VRRM rating margin for 230VAC mains surge tolerance, low VF for thermal management in compact adapters, TRR suitability for high-frequency flyback operation, and DO-201AD package compatibility with wave-soldered PFC front-ends.
Technical Context
This device operates as a single-phase, half-wave silicon rectifier optimized for 50/60Hz and higher-frequency switching applications up to ~100kHz. Its 50ns reverse recovery time enables reduced switching losses compared to standard recovery diodes, while the 125A non-repetitive surge rating supports inrush current handling during cold-start conditions.
The DO-201AD package provides mechanical robustness and thermal path via 9.5mm lead length, supporting 3.0A average forward current at 50°C ambient. Junction capacitance of 70pF at 4V reverse bias minimizes capacitive coupling in EMI-sensitive input filters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 400 V - Withstands peak line voltage + safety margin for 230VAC systems with 1.5× surge allowance |
| IF(AV) | 3.0 A @ TA = 50°C - Sustains continuous output current in 15–25W offline SMPS designs |
| VF | 1.1 V @ IF = 3.0 A DC - Delivers <3.3W conduction loss at full load, easing thermal design |
| TRR | 50 ns - Enables efficient operation in 65–100kHz flyback converters without excessive ringing |
| IR | 10 µA @ 400 V, 25°C - Ensures minimal leakage in high-impedance hold-up circuits |
| CJ | 70 pF @ 4 V, 1 MHz - Limits displacement current in EMI filter Y-cap networks |
Pinout & Package
DO-201AD molded plastic package with axial plated leads; cathode identified by color band. Approximate weight: 1.2 g. UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | AC input connection point | Accepts incoming phase or neutral leg prior to rectification; requires creepage clearance ≥3.2 mm |
| Cathode | DC output connection point | Feeds bulk capacitor or PFC stage; polarity marking ensures correct orientation on PCB |
Key Features
| Feature | Design Value |
|---|---|
| High-speed recovery | 50 ns TRR enables clean commutation in 65–100 kHz SMPS without snubber dependency |
| Low forward voltage | 1.1 V drop at 3.0 A reduces conduction loss by ~25% vs. standard 1N5408 in same footprint |
| High surge capability | 125 A peak surge withstands 10-cycle 230VAC cold-start inrush without degradation |
| Low leakage | 10 µA IR at 400 V ensures stable DC bus hold-up over temperature and time |
Applications
| AC/DC Adapter Input Stage | Industrial Control Power Supply |
|---|---|
Use Scenario: Rectifying 230VAC mains input in 18–24W wall adapters with passive PFC. IC Role / Device Role / Timing Role: Primary-side unidirectional current valve converting AC to pulsating DC before bulk capacitor. Use Value: 400V VRRM provides 1.7× margin over 230VAC peak (325V), preventing avalanche failure during brownouts. | Use Scenario: Front-end rectification in DIN-rail mounted 24V/3A PLC power modules. IC Role / Device Role / Timing Role: High-reliability AC input bridge leg (used x4 per full-wave configuration). Use Value: 150 µA IR at 55°C case temperature maintains regulation stability across -25°C to +70°C operating range. |
| LED Driver Auxiliary Supply | UPS Battery Charger Input |
Use Scenario: Generating low-power auxiliary rail for controller ICs in isolated LED drivers. IC Role / Device Role / Timing Role: Half-wave rectifier feeding linear regulator or buck converter startup circuitry. Use Value: 70pF junction capacitance avoids noise coupling into sensitive analog feedback paths. | Use Scenario: Input rectification in 48V/5A battery charger with active inrush limiting. IC Role / Device Role / Timing Role: Surge-tolerant rectifier handling repeated 125A inrush events during AC reconnection. Use Value: 125A peak surge rating exceeds IEC 61000-4-5 Level 3 (1kV/42Ω) transient requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-efficiency rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UF3005-T | Same DO-201AD package; 50ns TRR retained but VF reduced to 1.0V @ 3A; VRRM unchanged at 400V | Lower conduction loss improves efficiency in thermally constrained adapters | Select UF3005-T when >0.5% efficiency gain or <5°C junction temp reduction is required |
| ES3D-E3/57T | TO-220AC package; 200V VRRM; 3A IF(AV); 35ns TRR; VF = 0.95V @ 3A | Requires heatsink mounting; suited for higher-current, lower-voltage industrial supplies | Choose ES3D only if system operates ≤120VAC and demands sub-40ns recovery with forced-air cooling |
Compared with HER305-T, UF3005-T offers identical speed and voltage rating with improved conduction efficiency, while ES3D-E3/57T trades off voltage headroom and package form factor for faster recovery and lower VF - making it unsuitable as a drop-in replacement but viable in redesigned low-VRRM systems.
Availability
HER305-T is available at Aetrix Electronics and suitable for AC/DC adapter input stages, industrial control power supplies, LED driver auxiliary rails, and UPS battery charger inputs requiring stable component supply and legacy design continuity.
Supply support for HER305-T 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 Americas.
The HER30x series belongs to Diodes' high-efficiency rectifier product line, engineered specifically for cost-sensitive, space-constrained offline power conversion where reliability and thermal performance outweigh ultra-fast recovery needs.
FAQ
Is HER305-T suitable for use in a 100kHz flyback converter?
Yes - its 50ns reverse recovery time and 70pF junction capacitance allow stable operation up to 100kHz without significant switching loss or voltage overshoot. Measured TRR under 0.5A/1.0A test conditions confirms consistent behavior in high-frequency hard-switching topologies.
What is the maximum allowable case temperature for continuous 3.0A operation?
HER305-T sustains 3.0A average forward current only at TC ≤ 55°C, as specified in the full-load reverse current rating. At higher case temperatures, derating is required per Figure 1 - e.g., 2.2A at TC = 80°C and 1.5A at TC = 100°C.
Can HER305-T replace HER304-T in an existing design?
Yes - both share identical DO-201AD package, pinout, and thermal characteristics; HER305-T offers 100V higher VRRM (400V vs. 300V) with no trade-off in VF, TRR, or surge rating, providing increased safety margin for 230VAC applications.
Why is HER305-T marked as "Not Recommended for New Designs"?
Diodes Incorporated recommends UF3005-T as a direct functional upgrade: same package and ratings, but with 1.0V VF (vs. 1.1V), improved efficiency, and active production status. HER305-T remains available for legacy repair and continuity, but lacks long-term roadmap support.
HER305-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-201AD, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 400 V
- Current - Average Rectified (Io):
- 3A
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 3 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 50 ns
- Current - Reverse Leakage @ Vr:
- 10 µA @ 400 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-201AD
- Operating Temperature - Junction:
- -65°C ~ 150°C
HER305-T FAQ
1.How can I place an order for HER305-T through Aetrix?
Please submit a Request for Quotation (RFQ) for HER305-T 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 HER305-T reliable?
The price and inventory of HER305-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for HER305-T is usually 5 days.
3.What payment methods are accepted for HER305-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for HER305-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for HER305-T?
HER305-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your HER305-T 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 HER305-T?
For technical support, including HER305-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your HER305-T requirements.
6.How does Aetrix verify that HER305-T is sourced from the original manufacturer or authorized distributors?
All HER305-T 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 HER305-T meets industry standards.
7.What is the process for return or replacement of HER305-T?
All HER305-T units undergo pre-shipment inspection (PSI). If there is an issue with HER305-T, 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 HER305-T part is unused and in its original packaging.
Return procedure for HER305-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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