BAT46 - 100V 150mA Small Signal Schottky Diode | STMicroelectronics
MPN: BAT46 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.14 | $1.40 |
| 100 | $0.09 | $9.00 |
| 500 | $0.06 | $30.00 |
| 1,000 | $0.045 | $45.00 |
BAT46 Overview
A Schottky diode uses a metal-semiconductor junction instead of a P-N junction, giving it a lower forward voltage drop and faster switching with minimal reverse-recovery charge. Within the semiconductor hierarchy, the BAT46 belongs to the discrete-semiconductor family: diode -> rectifier/Schottky diode -> signal diode -> small signal component. These devices are widely used where low forward losses and speed matter more than blocking capability.
Key features of the BAT46 include its high 100 V reverse rating for a small-signal Schottky - most comparable small-signal Schottky parts are limited to 40-70 V - along with low forward voltage, fast switching, and a stable glass DO-35 package suitable for hand soldering and legacy through-hole designs. Its soft, low conduction threshold also makes it a popular substitute for germanium diodes in low-level signal applications such as crystal radio detection and audio clipping circuits, a substitution validated by DigiKey forum curve comparisons against the 1N34A.
The device is manufactured by STMicroelectronics with equivalent BAT46 products also produced by Vishay General Semiconductor, giving designers multiple qualified sources. The glass package provides excellent hermeticity and temperature stability compared with molded plastic axial packages.
Typical applications include polarity protection, OR-ing and steering of low-current supplies, detector circuits in RF and crystal radios, clipping/clamping in guitar pedals and audio equipment, and general signal rectification up to 150 mA.
Design consideration: derate forward current with ambient temperature and verify reverse leakage at high temperature, since Schottky leakage rises exponentially; for higher current needs move to a rectifier-grade Schottky such as the 1N5817 family in DO-41.
This page synthesizes verified distributor data, cross-references, drop-in alternatives, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for BAT46 — 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 BAT46 (same form factor and footprint) — differing in Package, Diode Type, Mounting Type, Application Class, Average Forward Current (IF(AV)).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
BAT41
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.028 / Unit
View Datasheet →BAT42
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.02 / Unit
View Datasheet →BAT46
✅ Drop-In✓ In Stock
$0.045 / Unit
View Datasheet →1N5711
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.18 / Unit
View Datasheet →BAT46 Maximum Ratings & Electrical Characteristics
| Diode Type | Small signal Schottky diode |
| Reverse Voltage (VR) | 100 V |
| Average Forward Current (IF) | 150 mA |
| Package | DO-35 (axial, glass) |
| Mounting Type | Through Hole |
| Configuration | Single diode |
| Application Class | Protection and routing operations |
| RoHS Status | RoHS3 Compliant |
| REACH Status | Unaffected |
| MSL Level | 1 (Unlimited) |
| Series | BAT46 |
| Manufacturer Equivalents | STMicroelectronics, Vishay General Semiconductor |
BAT46 Pin Configuration
| Pin 1 | Anode — Anode lead (unbanded end of glass body) |
| Pin 2 | Cathode — Cathode lead (banded end of glass body) |
Typical Applications
BAT46 is suitable for 6 applications: Polarity Protection, Crystal Radio and AM Detection, Guitar Pedal Audio Clipping, Diode OR-ing of Low-Current Rails, Signal Clamping and Protection, General Small-Signal Rectification.
Polarity Protection
The BAT46 fits battery-input and DC-input protection circuits because its 100 V reverse rating far exceeds typical 5-24 V rail worst cases, while its Schottky forward voltage wastes minimal headroom in low-current paths. In series protection, the low forward drop preserves voltage accuracy for analog front ends supplied through the diode; in shunt reverse-polarity clamps, the high VR absorbs miswiring transients without avalanche risk. At signal-level currents the conduction loss is negligible, and the glass DO-35 package tolerates hand soldering during prototyping and rework. Designers should verify leakage at elevated ambient temperature, as Schottky IR rises exponentially.
Recommended
Crystal Radio and AM Detection
The BAT46 is a validated substitution for the germanium 1N34A in crystal radio detectors: DigiKey forum IV-curve measurements show the BAT46 conduction threshold sits well below silicon switching diodes like the 1N4148, improving sensitivity to weak AM envelope signals. Its 100 V rating provides large margin against RF peak voltages, and its 150 mA rating is far above any detector current. Unlike germanium, the BAT46 offers hermetic glass construction, consistent manufacturing, and stable characteristics over temperature. For best detection, load the diode with an impedance matched to the tank circuit and avoid DC-biasing, which would defeat the low-threshold advantage.
Recommended
Guitar Pedal Audio Clipping
In distortion and overdrive pedals, the BAT46 is a staple clipping diode because its soft Schottky knee (conducting below the roughly 0.6 V of a 1N4148) yields gentler, more compressed clipping. PedalPCB forum measurements ranked the BAT46 among the lowest-threshold silicon-family diodes, between germanium types and standard silicon parts, producing a distinct voicing in hard-clip and soft-clip configurations. Signal-path levels are in the millivolt-to-volt range, far inside the 100 V and 150 mA ratings. Builders commonly pair it with silicon or germanium diodes in asymmetric arrangements to tailor harmonic content and output level.
Recommended
Diode OR-ing of Low-Current Rails
The BAT46 suits diode-OR combiner circuits for backup power and redundant supplies at signal-level currents up to 150 mA. Its low Schottky forward voltage minimizes droop between the source and load, preserving regulator headroom, while the 100 V reverse rating withstands large inter-supply potential differences without damage. Typical uses include battery-backup feeds for real-time clocks, memory retention circuits, and sensor nodes. Designers should account for forward voltage as a fixed supply offset and select pull-up/bias resistors accordingly. For loads beyond 150 mA, upgrade to a Schottky rectifier such as the 1N5817 series in DO-41.
Recommended
Signal Clamping and Protection
The BAT46 clamps inductive kickback and protects sensitive inputs in low-current circuits: placed across relay coils, small solenoids, or sensor wiring, it diverts reverse transients before they reach driver transistors or ADC pins. Its fast Schottky recovery adds negligible delay, and the 100 V reverse rating covers most 12 V and 24 V industrial signaling environments with margin. In instrumentation front ends, its low conduction threshold keeps clamp engagement early, limiting overshoot excursions. The hermetic DO-35 glass package offers stable leakage characteristics over temperature, important in precision measurement paths where clamp leakage would otherwise corrupt signals.
Recommended
General Small-Signal Rectification
For general-purpose signal rectification - envelope detection, sample-hold charging, peak detectors, and AC signal steering - the BAT46 combines low forward drop, fast switching, and a 100 V blocking rating in one small package. Its low junction capacitance keeps loading light on high-impedance nodes compared with larger rectifier diodes, and the 150 mA rating covers most signal-conditioning workloads. The through-hole DO-35 format suits prototyping, point-to-point wiring, and legacy boards where SMD substitution is impractical. Engineer verification per the Vishay datasheet note remains the responsibility of the designer, as performance varies with circuit conditions over time.
Recommended
Recommended Products Summary
Engineering reference data for BAT46 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BAT41 | BAT42 | BAT46 (Vishay) | 1N5711 |
|---|---|---|---|---|---|
| Package | DO-35 (axial glass) | DO-35 - same | DO-35 - same | DO-35 - same | DO-35 - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Vishay Intertechnology | onsemi |
| Diode Technology | Schottky | Schottky | Schottky | Schottky | Schottky |
| Configuration | Single diode | Single diode | Single diode | Single diode | Single diode |
| Mounting | Through Hole | Through Hole | Through Hole | Through Hole | Through Hole |
Key Differentiators
- 100 V reverse rating in small-signal class (vs BAT42)
- True multi-source part (vs BAT46 (Vishay Intertechnology))
- Lower conduction threshold than 1N5711 (vs 1N5711)
Design Notes
The BAT46 is rated 150 mA average forward current. Estimated derating: Schottky diodes typically require derating above 25 C ambient; keep continuous load below ~100 mA in sealed enclosures to preserve thermal margin, and verify the datasheet derating curve for your ambient temperature. At these currents forward dissipation (VF x IF) is only tens of milliwatts, so the DO-35 glass body needs no heatsinking - but avoid sustained surge currents, which glass-body small-signal diodes tolerate less well than DO-41 rectifiers.
Do not substitute the 1N5817 on the same footprint - it is DO-41, physically larger than the BAT46's DO-35 body, and will not fit DO-35-drilled holes or computed axial lead-form layouts. When a second source is needed, use the Vishay BAT46 (identical 100 V/150 mA rating and package) or ST BAT41/BAT42 family members after verifying forward voltage against circuit thresholds. Also note Schottky reverse leakage rises exponentially with temperature; check IR at maximum ambient for precision or battery-powered circuits.
For the axial DO-35 package, provide lead spacing of at least the body length plus reasonable bend radius, and avoid stress-relief violations at the glass-to-lead seal - glass DO-35 bodies crack under rigid leadforming or proximity soldering. Hand-soldering is routine, but clip heatsink pliers between the body and the joint during extended iron contact. On mixed-technology boards, keep the banded (cathode) end orientation verified against the schematic before wave or hand soldering, since reversed protection diodes defeat the entire protection function.
Compliance Information
RoHS3 Compliant, REACH Unaffected, MSL 1 (Unlimited) per partgenie.ai distributor compliance summary. AEC-Q100 status not stated in provided data - automotive use requires manufacturer confirmation.
