Diodes Incorporated 1N4448WSQ-7-F

Overview

1N4448WSQ-7-F from Diodes Incorporated is a surface-mount fast-switching silicon signal diode in SOD323 package, rated for 75 V peak repetitive reverse voltage, 500 mA forward current, and 4.0 ns reverse recovery time; it delivers high conductance and low forward voltage (0.62 V @ 5 mA), and is AEC-Q101 qualified for automotive power management and signal routing circuits.

For engineers reviewing the 1N4448WSQ-7-F datasheet, 1N4448WSQ-7-F pinout, 1N4448WSQ-7-F application, or 1N4448WSQ-7-F equivalent, key selection criteria include reverse recovery speed, thermal resistance (625 °C/W), junction temperature range (–55 to +150 °C), and automotive qualification status - all critical for high-frequency switching and under-hood electronics design.

Technical Context

This diode operates as a unidirectional, low-capacitance (4.0 pF @ 0 V, 1 MHz) switching element with fast carrier recombination, enabling clean edge transitions in digital logic interfaces and clamp protection circuits. Its 0.62–1.25 V forward voltage span across 5–150 mA reflects consistent low-loss conduction behavior over wide dynamic load ranges.

The device uses an alloy-42 leadframe with matte tin plating, achieves moisture sensitivity level 1 per J-STD-020, and is packaged in halogen/antimony-free "Green" molding compound (UL 94V-0), supporting lead-free reflow assembly without degradation of t_RR or leakage performance.

Key Specifications

Pinout & Package

Package: SOD323 - ultra-compact 2-pin surface-mount plastic package (1.30 × 1.70 × 0.95 mm), cathode identified by molded band; weight ≈ 0.004 g; UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fast-switching diode applications.

Compared with BAS16W-7-F and 1N4148W-7-F, the 1N4448WSQ-7-F uniquely combines automotive qualification, tight t_RR tolerance, and low-V_F conduction - making it the preferred choice for safety-critical, thermally constrained, and high-reliability signal switching in vehicle ECUs and ADAS subsystems.

Availability

1N4448WSQ-7-F is available at Aetrix Electronics and suitable for automotive engine control units, industrial programmable logic controller input modules, and medical infusion pump motor drivers requiring stable component supply across extended product lifecycles.

Supply support for 1N4448WSQ-7-F 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, testing, and wafer fabrication facilities across Asia and the U.S.

The 1N4448WSQ-7-F belongs to Diodes' high-speed switching diode product line, engineered specifically for automotive-grade signal integrity, transient immunity, and thermal robustness in harsh-environment electronic control modules.

FAQ

Is the 1N4448WSQ-7-F pin-compatible with the standard 1N4448 through-hole diode?

No - the 1N4448WSQ-7-F uses the SOD323 surface-mount package with anode/cathode terminals spaced 1.70 mm apart, whereas the legacy 1N4448 uses DO-35 axial leads. Physical mounting, PCB footprint, and thermal management requirements differ significantly; direct replacement requires board redesign.

What is the maximum allowable soldering temperature profile for the 1N4448WSQ-7-F?

The device complies with IPC/JEDEC J-STD-020 moisture sensitivity level 1, permitting standard lead-free reflow profiles with peak temperature up to 260 °C for ≤60 seconds. Preconditioning is not required, and the "Green" molding compound remains stable under typical 240–260 °C ramp-soak-reflow cycles.

Does the 1N4448WSQ-7-F support bidirectional ESD protection?

No - it is a unidirectional silicon junction diode. For bidirectional ESD clamping, a dedicated TVS array (e.g., D3V3M1U2LP-7) or back-to-back diode configuration is required. This part provides only forward conduction and reverse blocking, not symmetric transient voltage suppression.

How does the 1N4448WSQ-7-F's thermal resistance compare to larger-package alternatives like SMA or SMC diodes?

At 625 °C/W (Junction-to-Ambient, FR-4 board), its thermal resistance is higher than SMA (≈300 °C/W) or SMC (≈150 °C/W) packages due to smaller die attach area and limited copper spreading. Full 500 mA current must be limited to ≤85°C ambient unless enhanced PCB copper pours or thermal vias are implemented per Diodes' recommended pad layout.