BAT41 - 100V 100mA Schottky Diode DO-35 | STMicroelectronics
MPN: BAT41 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.12 | $0.12 |
| 10 | $0.09 | $0.90 |
| 100 | $0.055 | $5.50 |
| 500 | $0.038 | $19.00 |
| 1,000 | $0.028 | $28.00 |
BAT41 Overview
A Schottky diode is a metal-to-silicon rectifier that conducts with a substantially lower forward voltage than a standard PN-junction silicon diode, and it stores almost no minority-carrier charge, so it switches between conducting and blocking states extremely quickly. Within the power-management hierarchy, the BAT41 sits in the small-signal switching diode class: it is not a power rectifier but a signal-path and low-current switching element used across analog, audio, and digital boards.
Key features include the 100 V reverse voltage rating, which is unusually high for a small-signal Schottky; a low forward turn-on voltage that minimizes signal loss in detection and clamping circuits; and integrated guard-ring protection against excessive voltage events such as electrostatic discharge. According to STMicroelectronics, the series is specially suited for switching-mode operation with low reverse leakage (IR) losses.
Technically, the BAT41 uses a metal-silicon junction with a PN guard ring, yielding very low forward and reverse recovery times and low junction capacitance. This combination makes it a common substitute for germanium diodes in soft-clipping and signal-detection roles, since its conduction curve is softer than standard silicon but with better temperature behavior and availability.
Typical applications include audio clipping and waveshaping in guitar pedals and reverb circuits, reverse-polarity and ESD protection clamps on signal lines, RF and video detectors, and general-purpose low-current rectification or ORing of low-voltage rails.
Design consideration: the DO-35 axial package dissipates little power; keep average forward current well below 100 mA and derate above approximately 25 C ambient per the manufacturer datasheet derating curve. For power rectification above roughly 0.5 A, choose a larger Schottky such as the 1N5817 instead.
This page synthesizes verified distributor data, drop-in alternatives across manufacturers, and practical design guidance not consolidated in any single datasheet.
Drop-in alternatives for BAT41 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with BAT41 (same form factor and footprint) β differing in Package, ESD Protection, Technology, Mounting Type, Diode Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
BAT42
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.02 / Unit
View Datasheet βBAT46WH
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.029 / Unit
View Datasheet βBAT85
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
BAT41
β Drop-Inβ In Stock
$0.028 / Unit
View Datasheet βBAT41 Maximum Ratings & Electrical Characteristics
| Device Type | Small Signal Schottky Barrier Diode |
| Repetitive Peak Reverse Voltage (VRRM) | 100 V |
| Average Forward Current (IF(AV)) | 100 mA |
| Package | DO-35 (Glass), axial through-hole |
| Technology | Metal-to-silicon Schottky with PN guard ring |
| Reverse Recovery Time | Very low (fast switching, per ST datasheet) |
| Turn-On Voltage | Very low (low turn-on, per ST datasheet) |
| ESD Protection | Integrated guard-ring protection against excessive voltage such as ESD |
| Mounting Type | Through Hole |
| Configuration | Single diode |
| Series Package Options | SOD-123 or SOD-523 (series variants); BAT41 base part in DO-35 |
BAT41 Pin Configuration
| Pin 1 | A (Anode) β Anode terminal - unmarked end of DO-35 glass body |
| Pin 2 | K (Cathode) β Cathode terminal - banded end of DO-35 glass body |
Typical Applications
BAT41 is suitable for 6 applications: Audio Clipping and Waveshaping, Signal Line ESD and Voltage Clamping, Envelope Detection and Precision Rectification, Reverse Polarity and Low-Current Rail ORing, General-Purpose Fast Switching, Germanium-Diode Replacement in Legacy Designs.
Audio Clipping and Waveshaping
The BAT41 is a staple in guitar-pedal clipping stages because its Schottky junction begins conducting at a lower forward voltage than standard silicon diodes, producing a soft, germanium-like compression curve that engineers and tone designers deliberately seek. According to community comparisons on PedalPCB and freestompboxes forums, BAT41 clipping sits between germanium and conventional silicon diodes in signal level and saturation character. Placed in the feedback path of an op-amp gain stage or as back-to-back pairs to ground, the diode's low forward recovery time keeps clipping artifacts free of slow-recovery distortion, while its 100 V rating is far above any audio signal swing, guaranteeing symmetric, predictable conduction. Substituting other diodes audibly changes the tone, so the BAT41 should be preserved where the design calls for it.
Recommended
Signal Line ESD and Voltage Clamping
ST states the BAT41 has integrated guard-ring protection against excessive voltage such as electrostatic discharge, which makes it a practical low-cost clamp on external signal inputs. Connected from a signal line to a supply or ground rail, the diode's low forward turn-on voltage diverts transients before they reach sensitive CMOS inputs, and its low junction capacitance means the clamp does not visibly slow down digital edges or distort fast analog waveforms. The 100 V reverse rating gives generous margin against ordinary line excursions, and the low reverse leakage (IR) per the ST datasheet means the clamp adds negligible DC error to high-impedance nodes. For production, verify the clamping energy against the intended ESD stress level, since the BAT41 is a general-purpose part rather than a rated TVS device.
Recommended
Envelope Detection and Precision Rectification
Because the BAT41 is a low-capacitance small-signal Schottky with very low forward and reverse recovery times, it is well suited to envelope detectors, peak detectors, and precision-rectifier feedback elements in audio, instrumentation, and AM demodulation circuits. The Schottky junction rectifies effectively at low signal amplitudes where a standard silicon diode's higher threshold would lose the peaks entirely, and the low capacitance preserves high-frequency content, extending the usable detection band. In an active half-wave rectifier the diode sits inside the op-amp feedback loop, so its forward voltage is divided down by the loop gain, and the BAT41's fast recovery prevents switching glitches at the zero crossing. Designers should confirm the actual junction capacitance in the ST datasheet when operating at radio frequencies.
Recommended
Reverse Polarity and Low-Current Rail ORing
In battery-powered and pedalboard equipment, the BAT41 serves as a series reverse-polarity protector or as an ORing diode between two low-current supply sources. Its very low forward voltage drops only a few hundred millivolts at signal-class currents, preserving valuable headroom in 9 V battery systems where every volt counts, and its 100 V rating comfortably survives accidental connection to higher-voltage adapters - a common field failure mode that destroys 30 V-class Schottky protectors. The low reverse leakage keeps standby drain negligible when the diode blocks, important for battery life. For loads above roughly 50 to 100 mA the designer should instead use a higher-current Schottky such as the 1N5817 family, since the BAT41 average forward current rating is 100 mA.
Recommended
General-Purpose Fast Switching
Per the ST datasheet, the BAT41 series is specially suited for switching-mode operation with low reverse leakage losses, making it a convenient general-purpose switching element in low-current logic interfacing, waveform shaping, and flyback-path roles on mixed-signal boards. The metal-to-silicon junction has negligible reverse recovery, so switching transitions are limited by junction capacitance rather than stored charge, enabling clean edges in medium-speed circuits. Compared with the 1N4148 silicon switching diode, the BAT41 trades a slightly higher capacitance for a much lower conduction threshold and higher 100 V blocking rating. In practice it fills the niche between ultrafast silicon switching diodes and power Schottky rectifiers for small-signal switch duties on through-hole assemblies.
Recommended
Germanium-Diode Replacement in Legacy Designs
Legacy audio, measurement, and radio circuits originally designed around germanium diodes such as the OA91 or 1N34A are increasingly hard to maintain because germanium parts suffer from wide parameter spread, high leakage, and shrinking availability. The BAT41 is widely used as the modern replacement: community references note its conduction curve is quite similar to germanium while offering far better temperature stability, tighter manufacturing tolerance, and ESD robustness from the integrated guard ring. When retrofitting, the low Schottky forward voltage closely reproduces the original detection or clipping behavior, and the 100 V rating removes the avalanche risk germanium parts had. Designers should expect slightly lower leakage than germanium, which usually improves DC accuracy in detector retrofits.
Recommended
Recommended Products Summary
Engineering reference data for BAT41 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BAT42 | BAT46 | BAT85 | BAT41 (Vishay) |
|---|---|---|---|---|---|
| Package | DO-35 glass axial | DO-35 glass axial - same | DO-35 glass axial - same | DO-35 glass axial - same | DO-35 glass axial - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Vishay Intertechnology |
| Device Type | Small-signal Schottky | Small-signal Schottky | Small-signal Schottky | Small-signal Schottky | Small-signal Schottky |
| Guard-Ring ESD Protection | Yes (per ST datasheet) | Yes (same family guard ring) | Yes (same family guard ring) | Yes (same family guard ring) | Yes (PN junction guard ring) |
| Drop-In Compatibility | Reference part | Same footprint; verify 100 V rating requirement | Same footprint; verify 100 V rating requirement | Same footprint; verify 100 V rating requirement | Full pin-to-pin, parametric equivalent |
| Primary Use Case | Low-VF signal switching, clipping, detection at up to 100 V | Low-voltage signal Schottky duty | Higher-current low-voltage Schottky duty | Higher-current Schottky switching | Identical to this product |
Key Differentiators
- 100 V reverse rating in a small-signal Schottky (vs BAT46)
- Germanium-like soft conduction with modern reliability (vs 1N34A)
- Full second-source availability (vs BAT85)
Design Notes
Do not assume all BAT41-family diodes carry the 100 V rating. Only the BAT41 itself is rated 100 V; the closely related BAT42, BAT46, and BAT85 have lower reverse voltage ratings (commonly 30 V to 40 V class) and will avalanche or fail if substituted in circuits that exploit the BAT41's 100 V blocking capability - for example reverse-polarity protection against 48 V adapters. Always read the specific datasheet of the exact MPN before a substitution, and respect the 100 mA average forward current limit; for higher currents step up to a 1N5817-class power Schottky.
The BAT41's value in signal paths comes from its low capacitance and negligible reverse recovery, but its actual junction capacitance is voltage dependent - capacitance is higher at low reverse bias and falls as reverse voltage increases. In RF detector or fast clipper layouts, keep leads short (the DO-35 axial body plus trim leads add inductance of roughly a few nH per centimeter) and route the diode away from high-impedance nodes it is not clamping. Verify the capacitance-versus-voltage curve in the ST datasheet when the operating frequency approaches the high MHz range.
The DO-35 glass body has very limited thermal capability: with only 100 mA average forward current rating and a forward voltage on the order of a few hundred millivolts, dissipation must be kept to the tens-of-milliwatts range, and the datasheet derating curve reduces allowable dissipation as ambient temperature rises. Estimated rule of thumb: at 0.3 V forward voltage and 100 mA, dissipation is about 30 mW - fine for signal duty, but repeated operation near the current limit in a hot enclosure risks exceeding the derated limit. For sustained load currents, derate conservatively or select a larger package.
Compliance Information
Compliance statements were not present in the retrieved web data. Download the official compliance certificate from the STMicroelectronics BAT41 product page for regulatory documentation.
