Diodes Incorporated BAS40W-04-7-F

Overview

BAS40W-04-7-F from Diodes Incorporated is a surface-mount Schottky barrier diode in SOT323 package, rated for 40 V peak repetitive reverse voltage, 200 mA forward current, and featuring 380 mV typical forward voltage at 1 mA and 5 ns reverse recovery time. It serves as a high-speed switching and clamping device in low-voltage DC-DC converter feedback paths and signal-level rectification.

For engineers reviewing the BAS40W-04-7-F datasheet, BAS40W-04-7-F pinout, BAS40W-04-7-F application, or BAS40W-04-7-F equivalent, key selection criteria include low VF for efficiency-critical 3.3 V/5 V rail clamping, fast trr for high-frequency (>1 MHz) switching node snubbing, ESD-protected junction guard ring, and SOT323 footprint compatibility with space-constrained portable power management layouts.

Technical Context

This Schottky diode employs a platinum-silicide (PtSi) or similar low-barrier metal-semiconductor junction to achieve low forward voltage drop and minimal minority-carrier storage, enabling nanosecond-scale reverse recovery. Its guard-ringed PN structure suppresses transient-induced avalanche breakdown and improves ESD robustness beyond standard Schottky designs.

Rated for operation from –55 °C to +125 °C and qualified to J-STD-020 Level 1 moisture sensitivity, it supports reflow assembly without preconditioning. The 625 °C/W thermal resistance reflects its ultra-small SOT323 thermal mass and requires careful PCB copper pour design for sustained 200 mW dissipation.

Key Specifications

Pinout & Package

Package: SOT323 - ultra-small plastic surface-mount package (2.0 × 2.225 × 0.9 mm), lead-free, RoHS-compliant, with matte tin-plated terminals solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NSR0230HT1G and RB520S-40T1G, BAS40W-04-7-F uniquely combines 40 V rating, sub-400 mV VF at low current, 5 ns trr, and integrated guard-ring ESD protection in the SOT323 footprint-making it optimal for space-constrained, mixed-signal systems requiring both performance and ruggedness.

Availability

BAS40W-04-7-F is available at Aetrix Electronics and suitable for USB port protection, DC-DC converter feedback clamping, and RF detector input stages requiring stable component supply across industrial, consumer, and medical electronics programs.

Supply support for BAS40W-04-7-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, manufacturing, and sales operations across Asia, Europe, and North America.

The BAS40W series belongs to Diodes' high-speed Schottky diode product line, engineered specifically for low-loss, high-frequency signal routing and power rail protection in compact, battery-operated, and ESD-sensitive electronic systems.

FAQ

What is the polarity marking for BAS40W-04-7-F on the SOT323 package?

The cathode is marked by a single horizontal bar on the top surface of the SOT323 package, aligned with Pin 2. Pin 1 (anode) is located at the opposite end of the package, adjacent to the chamfered corner. This marking matches the standard SOT323 pin 1 indicator defined in JEDEC MO-203.

Can BAS40W-04-7-F replace BAS40W-05-7-F or BAS40W-06-7-F in a design?

No-BAS40W-04-7-F, -05-7-F, and -06-7-F differ in reverse voltage rating: -04 = 40 V, -05 = 50 V, -06 = 60 V. Substituting -04 for -05/-06 risks avalanche failure under higher reverse bias. All share identical package, VF, trr, and thermal specs, but VRRM is not interchangeable.

Is BAS40W-04-7-F suitable for reflow soldering per IPC-J-STD-020?

Yes-it is rated Moisture Sensitivity Level 1, meaning it may be stored indefinitely at ≤30 °C/60% RH and requires no baking prior to standard lead-free reflow (peak 260 °C). Its SOT323 construction and matte tin plating ensure reliable wetting and joint formation under J-STD-020 profile conditions.

Does the guard ring affect the diode's forward conduction characteristics?

No-the guard ring is a separate, lightly doped PN structure surrounding the active Schottky junction and does not participate in forward conduction. It remains reverse-biased during normal operation and only conducts during transient overvoltage events, preserving the diode's specified VF, trr, and CT values under steady-state conditions.