onsemi 1N5821RL

Overview

1N5821RL from STMicroelectronics is a low-drop axial power Schottky rectifier in DO-201AD package, rated for 30 V repetitive peak reverse voltage, 3 A average forward current at 110°C, and 0.5 V max forward voltage at 3 A and 25°C. It delivers negligible switching losses and extremely fast recovery for high-frequency DC/DC converters and SMPS output stages.

For engineers reviewing the 1N5821RL datasheet, 1N5821RL pinout, 1N5821RL application, or 1N5821RL equivalent, key selection criteria include its 30 V V_RRM, 80 A non-repetitive surge rating, 10,000 V/µs dV/dt capability, and thermal resistance of 80 °C/W (junction-to-ambient, 10 mm lead length).

Technical Context

This Schottky diode operates via majority-carrier conduction, eliminating minority-carrier storage delay and enabling sub-nanosecond reverse recovery. Its metal–semiconductor junction yields low forward voltage and high efficiency in low-voltage, high-current paths.

Designed for unidirectional power conversion, it supports free-wheeling, polarity protection, and battery charging circuits where low conduction loss and thermal stability up to 150°C junction temperature are critical.

Key Specifications

Pinout & Package

DO-201AD axial package with cathode identified by a ring marking. Leads are tinned copper, 1.30 mm diameter, with 25.4 mm overall length and 9.5 mm body length. Mounting requires ≥15 mm straight lead section before bending.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky rectifier applications.

Compared with SB330-E3/54 and SS34, the 1N5821RL offers the lowest forward voltage among axial 30 V Schottkys and superior surge robustness-critical for high-reliability through-hole power supplies where thermal cycling and mechanical stress are concerns.

Availability

1N5821RL is available at Aetrix Electronics and suitable for switch-mode power supplies, DC/DC converters, and battery charging circuits requiring stable component supply, long-term obsolescence management, and traceable lot-level sourcing.

Supply support for 1N5821RL 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The 1N582x series belongs to ST's legacy axial Schottky rectifier product line, engineered specifically for high-efficiency, high-reliability power conversion in cost-sensitive, thermally constrained applications.

FAQ

What is the maximum junction temperature for continuous operation?

The 1N5821RL has a maximum operating junction temperature of 150°C, verified per absolute maximum ratings. Derating begins above 110°C ambient when mounted with 10 mm leads; full 3 A current is only sustainable below 110°C ambient with natural convection.

Is the 1N5821RL RoHS compliant and halogen-free?

Yes, the 1N5821RL meets RoHS Directive 2011/65/EU and is halogen-free per STMicroelectronics' specification document "ECOPACK® Definitions." The DO-201AD epoxy package complies with UL94 V-0 flammability rating.

Can this diode be used in place of a 1N5822 in a 24 V system?

No-while both share the same package and thermal specs, the 1N5822 has 40 V V_RRM versus 30 V for the 1N5821RL. In a 24 V system with >30 V transients (e.g., load dump), the 1N5821RL risks avalanche breakdown; substitution requires validation of worst-case reverse voltage.

What is the typical junction capacitance at 4 V reverse bias?

Per Figure 8 in the datasheet, the typical junction capacitance is 25 pF at V_R = 4 V and T_j = 25°C. This value decreases with increasing reverse voltage and affects high-frequency switching noise and EMI filtering behavior.