My Inquiry
My Account
Diodes Incorporated 1N5821-B
- Part No.:
- 1N5821-B
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Diodes
- Package:
- DO-201AD, Axial
- Datasheet:
-
1N5821-B.pdf
- Description:
- DIODE SCHOTTKY 30V 3A DO201AD
- Quantity:
- Payment:
- Shipping:
Inventory:9,364
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N5821-B from Diodes Incorporated is a 3.0A, 30V Schottky barrier rectifier in DO-201AD package, featuring low forward voltage drop (0.475V @ 3A), high surge capability (80A), and thermal resistance of 40°C/W. It serves as a primary freewheeling or polarity protection diode in DC-DC converters and low-voltage power supplies.
For engineers reviewing the 1N5821-B datasheet, 1N5821-B pinout, 1N5821-B application, or 1N5821-B equivalent, key selection criteria include its 30V reverse blocking rating, 0.475V forward voltage at rated current, 80A non-repetitive surge rating, and DO-201AD mechanical compatibility with through-hole PCB layouts.
Technical Context
This Schottky rectifier uses a guard-ringed die construction to enhance transient immunity and reduce leakage under reverse bias. Its low junction-to-ambient thermal resistance (40°C/W) enables reliable operation at 3.0A average current when lead temperature is maintained ≤95°C.
The device exhibits typical total capacitance of ~100pF at 5V reverse bias (1MHz), supporting high-frequency switching applications such as 50–500kHz DC-DC flyback and buck converters where fast recovery and minimal stored charge are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 30 V - Maximum repetitive reverse voltage before breakdown; sets upper limit for input-side voltage clamping in polarity protection circuits |
| IO @ TL=95°C | 3.0 A - Average rectified output current with leads held at 95°C; defines continuous conduction capability in thermally constrained layouts |
| VFM @ IF=3.0A | 0.475 V - Forward voltage drop at rated DC current; directly determines conduction loss (1.425W) and thermal load in 3A applications |
| IFSM @ 8.3ms | 80 A - Non-repetitive surge current rating; supports inrush current handling during power-up in capacitive-input supplies |
| RJA | 40 °C/W - Junction-to-ambient thermal resistance; used to calculate junction temperature rise (ΔTj = Pd × RJA) for reliability margining |
| IRM @ 25°C | 2.0 mA - Peak reverse leakage at rated DC blocking voltage; impacts standby power loss in battery-powered polarity guards |
Pinout & Package
DO-201AD package: axial-leaded, molded plastic case with cathode band marking; 1.1g mass; UL 94V-0 rated; compatible with wave soldering per MIL-STD-202 Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Lead 1) | Current entry point under forward bias | Connected to lower-potential side (e.g., ground or switch node) in freewheeling paths; must handle full load current and surge |
| Cathode (Lead 2, banded end) | Current exit point under forward bias | Connected to higher-potential rail (e.g., input supply or inductor output); polarity marking ensures correct orientation in PCB silkscreen |
Key Features
| Feature | Design Value |
|---|---|
| Guard-ringed Schottky die | Reduces reverse leakage drift under temperature stress and improves ESD robustness without sacrificing VF performance |
| Low VF at 3A (0.475V) | Enables >92% efficiency in 5V-output buck converters operating at 3A, minimizing heatsink requirements |
| 80A IFSM rating | Withstands 120Hz line-frequency surges and DC-DC startup transients without degradation in industrial control power rails |
| DO-201AD mechanical standard | Ensures drop-in replacement compatibility with legacy designs using 1N58xx series; 9.5mm lead spacing matches common through-hole footprints |
Applications
| DC-DC Converter Freewheeling Diode | Polarity Protection in 12V Automotive Modules |
|---|---|
Use Scenario: Used across the inductor in a 5V/3A synchronous buck converter to provide low-loss current recirculation during high-side FET off-time. IC Role / Device Role / Timing Role: Freewheeling diode enabling continuous inductor current flow and maintaining output regulation during PWM dead time. Use Value: 0.475V VF reduces conduction loss by 40% vs. comparable silicon rectifiers, lowering thermal stress on adjacent MOSFETs and PCB copper. | Use Scenario: Placed in series with the VIN rail of an automotive infotainment module to block reverse battery connection. IC Role / Device Role / Timing Role: Unidirectional current gate preventing damage from accidental negative supply insertion during service or assembly. Use Value: 30V VRRM exceeds 12V system's worst-case load-dump spikes (up to 28V), while 80A IFSM survives jump-start surges without failure. |
| Low-Voltage AC/DC Adapter Output Rectifier | Industrial Sensor Power Supply Polarity Guard |
Use Scenario: Rectifies secondary-side output of a 24VAC-to-12VDC transformer-based adapter powering PoE midspans. IC Role / Device Role / Timing Role: Half-wave rectifier converting AC waveform to pulsating DC prior to bulk capacitor filtering. Use Value: Low VF minimizes voltage droop under 3A peak load, preserving regulated 12V output stability across line and load variations. | Use Scenario: Installed inline between 24V field power and a PLC analog input module to prevent miswiring damage. IC Role / Device Role / Timing Role: Reverse-polarity blocking element ensuring safe operation even if field technicians reverse supply leads. Use Value: 3.0A IO rating supports sensor excitation currents up to 2.5A while maintaining <0.5V drop, avoiding signal reference shift in precision 4–20mA loops. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SB330 (ON Semiconductor) | Same 30V VRRM and 3A IO, but VF = 0.52V @ 3A; DO-201AD package | Slightly higher conduction loss; identical mounting and thermal profile | Select when prioritizing second-source availability over minimal VF advantage |
| SS34 (Vishay) | 30V VRRM, 3A IO, VF = 0.55V @ 3A; SMA surface-mount package | Requires PCB redesign for SMT; lacks axial lead mechanical robustness in vibration-prone environments | Choose only for space-constrained, fully SMT designs where rework tolerance is acceptable |
Compared with SB330 and SS34, the 1N5821-B delivers the lowest forward voltage in the 3A/30V axial-leaded class, making it optimal for thermally sensitive through-hole power stages where efficiency and lead-mounted heatsinking are jointly prioritized.
Availability
1N5821-B is available at Aetrix Electronics and suitable for DC-DC converter freewheeling, automotive polarity protection, and industrial sensor power supply applications requiring stable component supply and long-term manufacturability.
Supply support for 1N5821-B 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 1N58xx series belongs to Diodes' general-purpose Schottky rectifier product line, engineered for cost-sensitive, high-volume power conversion and protection applications in consumer, industrial, and automotive systems.
FAQ
What is the maximum junction temperature for continuous operation of the 1N5821-B?
The 1N5821-B has an operating junction temperature range of –65°C to +125°C. For continuous 3.0A operation, the lead temperature must be limited to 95°C per the derating curve; this corresponds to a maximum steady-state junction temperature of approximately 135°C under typical RJA conditions, staying within absolute maximum ratings.
Can the 1N5821-B replace a 1N5822 in a 24V input circuit?
No - the 1N5822 has a 40V VRRM rating, while the 1N5821-B is rated for 30V. In a 24V system subject to load dump transients (which can exceed 35V), the 1N5821-B risks reverse breakdown. Use only where worst-case reverse voltage remains below 30V, or select the 1N5822 for margin.
Is the 1N5821-B suitable for high-frequency switching above 1MHz?
Yes - its Schottky structure provides near-zero reverse recovery time, and typical junction capacitance is ~100pF at 5V reverse bias (1MHz). This supports efficient operation in SMPS designs up to 500kHz; above 1MHz, layout parasitics dominate, but the device itself imposes no fundamental frequency limit.
Does the DO-201AD package support automated through-hole insertion?
Yes - the DO-201AD package has standardized axial lead geometry (7.2–9.5mm body width, 4.8–5.3mm lead diameter) and meets MIL-STD-202 solderability requirements. It is compatible with standard wave soldering and automated axial component insertion equipment used in high-volume manufacturing.
1N5821-B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-201AD, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Technology:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 30 V
- Current - Average Rectified (Io):
- 3A
- Voltage - Forward (Vf) (Max) @ If:
- 500 mV @ 3 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 2 mA @ 30 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-201AD
- Operating Temperature - Junction:
- -65°C ~ 150°C
1N5821-B FAQ
1.How can I place an order for 1N5821-B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5821-B 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 1N5821-B reliable?
The price and inventory of 1N5821-B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5821-B is usually 5 days.
3.What payment methods are accepted for 1N5821-B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5821-B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5821-B?
1N5821-B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5821-B 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 1N5821-B?
For technical support, including 1N5821-B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5821-B requirements.
6.How does Aetrix verify that 1N5821-B is sourced from the original manufacturer or authorized distributors?
All 1N5821-B 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 1N5821-B meets industry standards.
7.What is the process for return or replacement of 1N5821-B?
All 1N5821-B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5821-B, 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 1N5821-B part is unused and in its original packaging.
Return procedure for 1N5821-B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5821-B Tags
-
1N4448X-TP
Micro Commercial Co
-
1N4148WX-TP
Micro Commercial Co
-
1N4148TR
onsemi
-
MMSD4148T1G
onsemi
-
MMBD914LT3G
onsemi
-
BAS16HT1G
onsemi
-
1N914BWT
onsemi
-
BAS21LT1G
onsemi
-
LL4148
onsemi
-
BAS16LT1G
onsemi
-
MMSD914T1G
onsemi
-
BAV21W-7-F
Diodes Incorporated
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
