Diodes Incorporated SDM1U40CSP-7

Overview

SDM1U40CSP from Diodes Incorporated is a 40 V, 1.0 A Schottky barrier rectifier in chip-scale package (X3-WLB1406-2), featuring VF = 0.48 V max at 1.0 A, IR = 100 µA max at 40 V, and RθJA = 105 °C/W on 1-in² copper. It serves as a low-loss blocking or reverse-protection diode in space-constrained portable power rails.

For engineers reviewing the SDM1U40CSP datasheet, SDM1U40CSP pinout, SDM1U40CSP application, or SDM1U40CSP equivalent, key selection criteria include forward voltage drop at 1 A, thermal resistance under PCB layout constraints, reverse leakage at rated VRRM, and CSP footprint compatibility with high-density DC-DC output stages.

Technical Context

This Schottky rectifier uses a planar metal–semiconductor junction optimized for low VF and controlled IR across -55°C to +150°C operation. Its junction capacitance is 58 pF at 4 V, supporting fast switching in boost and buck converter freewheeling paths.

The X3-WLB1406-2 package integrates solder bumps directly on silicon die, enabling 0.84 mm² board area and low-profile mounting. Thermal performance depends critically on pad layout: RθJA drops from 190 °C/W (minimum pad) to 105 °C/W (1-in² copper), confirming its suitability for thermally demanding portable applications.

Key Specifications

Pinout & Package

Package: X3-WLB1406-2 chip-scale package (CSP), 0.84 mm² footprint, 0.275 mm typical height, cathode marked with dot. Solder bumps replace wire bonds; polarity defined by cathode dot adjacent to pin 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RB050M-30TR and SS14-HF, SDM1U40CSP delivers superior board-area efficiency (0.84 mm² vs ≥2.7 mm²), lower thermal resistance (105 vs ≥120 °C/W), and tighter leakage control (100 vs ≥500 µA), making it optimal for miniaturized, thermally sensitive portable power paths.

Availability

SDM1U40CSP is available at Aetrix Electronics and suitable for USB PD input protection, wireless charging receiver rectification, portable medical sensor power path management requiring stable component supply and consistent CSP footprint delivery.

Supply support for SDM1U40CSP 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 consumer, industrial, and automotive markets.

The SDM1U40CSP belongs to Diodes' CSP Schottky rectifier product line, engineered specifically for ultra-compact, high-efficiency DC-DC output stages and battery protection circuits in space- and thermal-constrained portable electronics.

FAQ

What is the maximum ambient temperature for continuous 1.0 A operation?

At 1.0 A, junction temperature must remain ≤150°C. With RθJA = 105 °C/W on 1-in² copper, maximum ambient temperature is 45°C (150 − 1.0 × 105). Derating curves in Figure 5 confirm 1.0 A is valid up to 45°C ambient under this layout; above that, current must be reduced per the derating slope.

Is SDM1U40CSP qualified for automotive applications?

No - SDM1U40CSP is not AEC-Q101 qualified. Diodes offers automotive-grade equivalents (e.g., SDM1U40QCS-7) with PPAP support and IATF 16949 manufacturing, but this part is intended for commercial portable electronics where AEC qualification is not required.

How is polarity identified on the X3-WLB1406-2 package?

Polarity is marked by a cathode dot adjacent to pin 1 (cathode solder bump). The device schematic shows cathode on the left, anode on the right; the dot aligns with the cathode bump location per the package outline drawing and marking diagram in DS36776 Rev. 6-2.

Can SDM1U40CSP replace a standard SOD-123 Schottky in existing designs?

Only with PCB redesign: X3-WLB1406-2 has different footprint (0.84 mm², 0.3×0.55 mm bumps) versus SOD-123 (2.7 mm², 1.5×2.8 mm body). Pad layout, stencil aperture, and reflow profile must be updated; electrical substitution is viable if VF, IR, and thermal goals are met with the new layout.