Diodes Incorporated SDM20U40Q-13

Overview

SDM20U40Q from Diodes Incorporated is a surface-mount Schottky barrier diode rated for 40 V peak repetitive reverse voltage, 250 mA average forward current, and 0.6 V maximum forward voltage at 200 mA. It features negligible reverse-recovery time (10 ns), 5 µA max reverse leakage at 30 V, and 50 pF typical junction capacitance at 0 V - optimized for high-frequency DC-DC converter freewheeling and reverse-polarity protection in space-constrained automotive modules.

For engineers reviewing the SDM20U40Q datasheet, SDM20U40Q pinout, SDM20U40Q application, or SDM20U40Q equivalent, key selection criteria include its AEC-Q101 qualification, SOD523 package thermal resistance (660 °C/W), low VF stability across -55°C to +150°C, and guard-ring construction for transient robustness in 12 V/24 V automotive power rails.

Technical Context

This Schottky diode employs a planar epitaxial structure with guard-ring passivation to suppress edge breakdown and enhance surge immunity. Its low barrier height enables sub-0.4 V forward drop at 10 mA while maintaining <5 µA IR at 30 V, supporting efficient synchronous rectification in compact buck converters.

The device's 10 ns reverse-recovery time and 50 pF junction capacitance at 1 MHz are measured under standardized conditions (IF = IR = 200 mA, IRR = 0.1 × IR, RL = 100 Ω), confirming suitability for >1 MHz switching topologies where capacitive loss and switching loss must be minimized.

Key Specifications

Pinout & Package

Package: SOD523 - ultra-small surface-mount plastic package (1.25 mm × 0.85 mm × 0.65 mm), moisture sensitivity level 1, matte tin–annealed terminals on Alloy 42 leadframe, cathode identified by band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RB520S-40T1G and NSR20F40NXT5G, the SDM20U40Q uniquely balances AEC-Q101 compliance, 250 mA continuous rating, and 0.6 V VF at full load - making it the only option validated for thermally demanding automotive BCMs operating continuously at 85°C ambient.

Availability

SDM20U40Q is available at Aetrix Electronics and suitable for automotive body control modules, USB-C power adapters, industrial sensor nodes, and LED driver power stages requiring stable component supply and long-term lifecycle support.

Supply support for SDM20U40Q 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-reliability power management, signal integrity, and protection solutions.

The SDM20U40Q belongs to Diodes' automotive-qualified Schottky diode product line, engineered specifically for low-VF, high-speed protection and freewheeling in 12 V/24 V vehicle subsystems with stringent PPAP and IATF 16949 requirements.

FAQ

Is SDM20U40Q suitable for use in AEC-Q101-compliant designs?

Yes. The SDM20U40Q is explicitly AEC-Q101 qualified, PPAP capable, and manufactured in IATF 16949 certified facilities. Test reports cover temperature cycling, HAST, ESD (HBM ≥2 kV), and mechanical shock - all documented in Diodes' Automotive Product Definitions portal.

What is the maximum allowable ambient temperature for continuous 250 mA operation?

Per Figure 4 (DC Forward Current Derating), the SDM20U40Q supports 250 mA up to 85°C ambient on FR-4 with recommended pad layout. Above 85°C, linear derating applies: current reduces to 125 mA at 125°C ambient due to its 660 °C/W R_θJA.

Does SDM20U40Q have a specified reverse recovery charge (Q_rr)?

No. As a Schottky diode, it exhibits majority-carrier conduction and negligible stored charge. The datasheet specifies t_RR = 10 ns (measured under IF = IR = 200 mA, IRR = 0.1 × IR), confirming absence of Q_rr-related switching loss - unlike PN-junction diodes.

Can SDM20U40Q replace a standard PN diode in a 24 V reverse-polarity circuit?

Yes, with design validation. Its 40 V V_RRM exceeds 24 V system requirements, and 0.6 V V_F cuts conduction loss by ~60% versus a typical 1N4007 (1.1 V). However, verify reverse leakage (5 µA @ 30 V) meets system standby budget, as Schottky leakage rises faster with temperature than PN diodes.