STMicroelectronics BAT41WFILM

Overview

BAT41WFILM from STMicroelectronics is a 100 V, 200 mA low-capacitance Schottky diode in SOT-323 package, optimized for high-frequency switching applications requiring minimal reverse recovery time (negligible), low leakage (<0.1 µA at 50 V, 25 °C), and ultra-low junction capacitance (3 pF typ. at 1 V). It serves as a fast rectifier or RF detector in portable power management and signal routing circuits.

For engineers reviewing the BAT41WFILM datasheet, BAT41WFILM pinout, BAT41WFILM application, or BAT41WFILM equivalent, key selection criteria include its 3 pF capacitance, 450 mV forward voltage at 1 mA, 1000 mV at 200 mA, 150 °C max junction temperature, and SOT-323 thermal resistance of 550 °C/W - critical for compact DC-DC converters and ESD-sensitive signal paths.

Technical Context

The BAT41WFILM implements a planar Schottky barrier structure with platinum-silicide contact, enabling sub-nanosecond switching and negligible minority-carrier storage. Its low C_j (3–10 pF) and fast t_rr are achieved without PN-junction trade-offs, making it suitable for 1–100 MHz signal clamping and RF envelope detection.

Thermal performance is defined by R_th(j-a) = 550 °C/W on epoxy FR4 PCB with recommended pad layout, and operation is validated from –65 °C to +150 °C junction temperature. Reverse leakage remains below 20 µA up to 100 °C at VR = 50 V.

Key Specifications

Pinout & Package

The BAT41WFILM is housed in a 3-pin SOT-323 (SC-70) plastic surface-mount package measuring 2.0 × 1.25 × 0.95 mm (L × W × H), with gull-wing leads and lead-free finish compliant with ECOPACK® standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NSR0230HT1G and RB520S-30T1G, BAT41WFILM delivers 3.3× higher reverse voltage margin and 4–13× lower junction capacitance - essential for robust 100 V industrial power supplies and 100 MHz RF front-ends where signal fidelity and voltage headroom are non-negotiable.

Availability

BAT41WFILM is available at Aetrix Electronics and suitable for USB port protection, RF envelope detection, DC-DC converter freewheeling, and logic-level signal clamping requiring stable component supply across production lifecycles.

Supply support for BAT41WFILM 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The BAT41 series belongs to ST's low-leakage Schottky diode product line, engineered specifically for high-frequency switching and signal integrity preservation in space-constrained, thermally demanding applications.

FAQ

What is the maximum reverse voltage the BAT41WFILM can withstand continuously?

The BAT41WFILM has a repetitive peak reverse voltage (V_RRM) rating of 100 V. This is the maximum DC or sinusoidal AC reverse voltage that may be continuously applied without risk of avalanche breakdown, verified per IEC 60747-2 under standard test conditions at T_j = 25 °C. Derating is required above 25 °C ambient per the IR vs. T_j curve in Figure 4.

Does BAT41WFILM have a cathode connection to the exposed pad?

Yes. The exposed pad (Pin 3) of the BAT41WFILM SOT-323 package is internally connected to the cathode. This design improves thermal conduction to the PCB and must be soldered to a grounded copper pour to achieve the specified R_th(j-a) = 550 °C/W. Electrical isolation of the pad invalidates thermal and reliability ratings.

How does the 3 pF junction capacitance impact high-frequency circuit performance?

A 3 pF junction capacitance minimizes loading on RF signal paths, enabling use up to 100 MHz with <0.5 dB insertion loss in 50 Ω systems. At 10 MHz, capacitive reactance is ~5.3 kΩ - high enough to avoid shunting intended signal currents, yet low enough to provide effective ESD transient diversion within nanoseconds.

Can BAT41WFILM replace BAT54 series diodes in existing designs?

No direct replacement: BAT54 variants (e.g., BAT54C) are dual-common-cathode diodes in SOT-23, whereas BAT41WFILM is a single-diode SOT-323 with higher V_RRM (100 V vs. 30 V) and lower C_j (3 pF vs. 10 pF). Pinout, package, and voltage rating differ - redesign of layout and voltage margin analysis is required before substitution.