Diodes Incorporated SR502-T

Overview

SR502-T from Diodes Incorporated is a high-current Schottky barrier rectifier in DO-201AD package, rated for 20 V repetitive peak reverse voltage, 5.0 A average forward current at 90°C, and 150 A non-repetitive surge current (8.3 ms half-sine). It delivers low forward voltage drop (0.55 V @ 5.0 A), low thermal resistance (15 K/W junction-to-lead), and integrated transient protection via guard ring - used in DC/DC converter output stages and high-efficiency AC-DC secondary-side rectification.

For engineers reviewing the SR502-T datasheet, SR502-T pinout, SR502-T application, or SR502-T equivalent, key selection criteria include forward voltage vs. temperature stability, surge robustness under inductive load switching, thermal performance with axial-lead PCB mounting, and compatibility with legacy DO-201AD footprint designs requiring <0.6 V conduction loss at 5 A.

Technical Context

This device operates as a unidirectional power rectifier leveraging platinum-silicide Schottky junction technology to minimize forward conduction loss and eliminate minority-carrier storage delay. Its guard ring structure enhances ruggedness against voltage transients, while the DO-201AD axial-leaded plastic case meets UL 94V-0 flammability rating.

Thermal design relies on direct junction-to-lead conduction (R_θJL = 15 K/W) with 9.5 mm lead length on vertical PCB mount; junction capacitance is 550 pF at 4.0 V reverse bias and 1.0 MHz, supporting moderate-speed switching in offline SMPS secondary rails.

Key Specifications

Pinout & Package

Package: DO-201AD - Axial-leaded, molded plastic case with cathode band marking; UL 94V-0 rated; weight ≈1.20 g; mountable in any orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SR502-T, SB520-T offers improved thermal and conduction performance in identical packaging, while SS52-T trades surge robustness and through-hole reliability for surface-mount compatibility - choice depends on assembly method, thermal envelope, and transient exposure profile.

Availability

SR502-T is available at Aetrix Electronics and suitable for AC-DC adapters, industrial DC/DC converters, automotive infotainment power supplies, and LED driver constant-current stages requiring stable component supply and proven legacy reliability.

Supply support for SR502-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, specializing in high-efficiency power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The SR series Schottky rectifiers target cost-sensitive, high-volume power conversion applications where low forward voltage, surge resilience, and standardized axial packaging are critical - especially in legacy-design refreshes and repair logistics.

FAQ

Is SR502-T suitable for synchronous rectification circuits?

No - SR502-T is a passive Schottky rectifier, not a synchronous rectifier controller or MOSFET gate driver. It functions as a self-commutated diode and cannot replace active synchronous rectification ICs like APW7159 or LM5145. However, it is commonly used in quasi-resonant or standard flyback topologies where synchronous control is not implemented.

What is the maximum operating temperature for continuous 5 A load?

The SR502-T supports 5.0 A average forward current only when the lead temperature (T_L) is maintained at ≤90°C, per JEDEC test conditions with 9.5 mm lead length and vertical PCB mounting. Junction temperature must remain ≤150°C; actual ambient limit depends on thermal design - typically ≤60°C with minimal copper area, or up to 85°C with 2 oz copper and thermal vias.

Does SR502-T have a qualified AEC-Q101 rating for automotive use?

No - SR502-T is not AEC-Q101 qualified. While its -65°C to +150°C operating range and guard ring structure support some automotive environments, Diodes Incorporated does not certify this part for automotive applications. For AEC-Q101-compliant alternatives, consider the SB520Q or SB540Q series, which undergo full stress testing per the standard.

Can SR502-T replace SR503-T in a 30 V design?

No - SR502-T has a 20 V V_RRM rating and will experience premature breakdown if subjected to 30 V reverse bias. Substituting it for SR503-T (30 V V_RRM) risks catastrophic failure during line transients or no-load conditions. Always match V_RRM to worst-case system reverse voltage with ≥20% margin.