MBRA340T3G - 3A 40V Schottky Rectifier SMA | onsemi
N.º de pieza: MBRA340T3G ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0.42 | $0,42 |
| 10 | $0.36 | $3,60 |
| 100 | $0.27 | $27,00 |
| 500 | $0.21 | $105,00 |
| 1.000 | $0.16 | $160,00 |
| 5.000 | $0.12 | $600,00 |
MBRA340T3G Descripción general
A Schottky diode is a semiconductor rectifier that uses a metal-semiconductor junction instead of a p-n junction, eliminating minority-carrier charge storage and producing an extremely fast switching device with a low forward voltage drop. Within the broader power-semiconductor taxonomy, Schottky rectifiers sit alongside standard recovery rectifiers, ultrafast rectifiers, and SiC diodes as the lowest-VF option for low-voltage, high-frequency applications. They are widely used as freewheeling and polarity-protection diodes in switch-mode power supplies, DC-DC converters, and battery-powered equipment.
Key features of the MBRA340T3G include low forward voltage drop (typical 450 mV at IF=3 A), high forward surge capability (IFSM up to 80 A per the onsemi datasheet family), low reverse leakage, and a guard-ring design for transient protection. The SMA package provides a compact surface-mount footprint with Underwriters Laboratory Flammability Classification 94V-0, lead-free reflow compatibility, and built-in strain relief for automated placement.
The MBRA340T3G is ideally suited for use as a low-voltage, high-frequency rectifier, as a freewheeling diode across inductive loads, and as a reverse-polarity protection diode at DC inputs. Compared with standard 1N5400-series rectifiers, the Schottky construction reduces conduction loss by roughly 30-50% at 3 A and eliminates reverse-recovery losses, simplifying thermal design in continuous-conduction converters.
When designing with this part, ensure that the maximum repetitive peak reverse voltage (40 V) is not exceeded under worst-case conditions including transient ringing on the input bus. The reverse leakage current rises with junction temperature - typical values near 20 mA at 25 C and significantly higher at 100 C - so adequate derating is required in thermally hot environments.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Pricing reflects data current as of 2026-10-09.
Alternativas directas para MBRA340T3G — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MBRA340T3G (mismo factor de forma y huella) — difiere en Package.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MBRA340T3
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
NRVBA340T3G
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
NRVBA340N
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
SS34
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
B340A-13-F
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
SK34
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MBRA340T3G Valores máximos y características eléctricas
| Rectifier Type | Schottky Power Rectifier |
| Maximum Repetitive Peak Reverse Voltage (VRRM) | 40 V |
| Average Rectified Forward Current (IF(AV)) | 3.0 A |
| Non-Repetitive Peak Forward Surge Current (IFSM) | 80 A |
| Forward Voltage (VF) at IF=3 A | 450 mV (typical) |
| Reverse Leakage Current (IR) at VR=40 V | 20 mA (typical at 25 C) |
| Rango de temperatura de unión de funcionamiento | -65 C to +125 C |
| Encapsulado | DO-214AC (SMA) |
| Tipo de montaje | Surface Mount |
| Construction | Epitaxial with oxide passivation and metal overlay contact |
| UL Flammability Rating | 94V-0 |
| Lead-Free / RoHS | Yes (per onsemi product page) |
| Reflow Solder Compatibility | 260 C peak per JEDEC J-STD-020 (per package family) |
| Configuration | Single diode, 2-pin |
| Polarity | Cathode indicated by molded body band |
Configuración de pines de MBRA340T3G
| Pin 1 | A (Anode) — Anode terminal of the Schottky rectifier |
| Pin 2 | K (Cathode) — Cathode terminal; indicated by the molded polarity band on the package body |
Aplicaciones típicas
MBRA340T3G es adecuado para 6 aplicacións: Switch-Mode Power Supply Output Rectifier, Freewheeling Diode in DC Motor Drive, Reverse-Polarity Protection at DC Input, OR-ing Diode in Redundant Power Systems, Low-Voltage Solar Battery Charging Rectifier, Automotive 12 V Load-Dump Protection Block.
Switch-Mode Power Supply Output Rectifier
The MBRA340T3G's 40 V reverse rating and 3 A average forward current make it well matched to the secondary-side rectification stage of 12 V and 24 V switch-mode power supplies. With a typical forward voltage of 450 mV at 3 A, conduction loss stays near 1.4 W - manageable on the SMA footprint with standard 1 oz copper. Unlike ultrafast recovery rectifiers, the Schottky junction eliminates reverse-recovery charge, reducing switching loss and EMI in continuous-conduction flyback and forward converters. Designers should parallel two MBRA340T3G devices for 6 A rails, ensuring symmetric current sharing through matched thermal mounting.
Recomendado
Freewheeling Diode in DC Motor Drive
In brushed DC motor drive circuits, the MBRA340T3G serves as a freewheeling diode across the motor winding or FET to dissipate stored inductive energy when the switch opens. Its 80 A non-repetitive surge rating (IFSM) handles the inductive kick at turn-off, while the low forward voltage keeps dissipation low during continuous PWM operation at 25 kHz. Compared with a 1N4007 equivalent, the MBRA340T3G cuts conduction loss roughly 60% and is small enough to fit in compact 24 V robotics and drone ESC designs.
Recomendado
Reverse-Polarity Protection at DC Input
The MBRA340T3G provides low-loss reverse-polarity protection at 12 V / 24 V DC inputs, blocking reverse battery connection and reverse adapter polarity in industrial and consumer products. With a typical VF of 450 mV at 3 A, total loss is approximately 1.35 W - much lower than the 700 mV+ drop of a P-MOSFET solution at the same current. The 40 V reverse standoff tolerates load-dump transients on automotive 12 V buses when paired with a TVS clamp. For higher-current rails (>5 A), designers typically switch to a P-MOSFET or ideal-diode controller to reduce dissipation.
Recomendado
OR-ing Diode in Redundant Power Systems
In redundant 12 V power architectures, the MBRA340T3G functions as an OR-ing diode to combine two independent supplies feeding a common load, blocking reverse current from the higher-voltage rail into the lower-voltage rail. The 450 mV typical VF at 3 A yields acceptable 1.35 W dissipation per channel. For higher efficiency (loss below 50 mV), designers should consider a hot-swap controller with external MOSFET instead, but for sub-5 A designs the MBRA340T3G remains a simple, low-cost solution requiring only two external components and the SMA footprint.
Recomendado
Low-Voltage Solar Battery Charging Rectifier
The MBRA340T3G is well suited as a blocking diode between a 12 V solar panel and a lead-acid or Li-ion battery charger, preventing reverse discharge at night. Its 450 mV forward drop reduces charging-circuit loss versus a 1N400x silicon rectifier (1.0 V drop), improving effective charge current by 5-10% in low-irradiance conditions. The 40 V reverse rating provides comfortable headroom above the 18 V open-circuit voltage of a 36-cell 12 V panel. Designers should pair with an MPPT controller such as the onsemi NCP1294 for full harvesting efficiency.
Recomendado
Automotive 12 V Load-Dump Protection Block
In automotive 12 V systems, the MBRA340T3G can serve as a secondary clamp or blocking element behind a TVS such as the SMBJ24A to handle 24 V load-dump transients. The 40 V reverse standoff handles a 24 V nominal bus plus transient ringing. For AEC-Q101 qualification in production vehicles, the onsemi NRVBA340T3G is the automotive-grade variant of the same die in the same package. The low leakage (20 mA typical at 25 C) keeps quiescent draw negligible in always-on body-control modules.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MBRA340T3G — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MBRA340T3 | NRVBA340T3G | NRVBA340N | SS34 | B340A-13-F |
|---|---|---|---|---|---|---|
| Package | DO-214AC (SMA) | DO-214AC (SMA) - same | DO-214AC (SMA) - same | DO-214AC (SMA) - same | DO-214AB (SMC) - larger, NOT pin-compatible | DO-214AC (SMA) - same |
| Brand | onsemi | onsemi | onsemi | onsemi | Vishay Intertechnology | Diodes Incorporated |
| VRRM (V) | 40 | 40 | 40 | 40 | 40 | 40 |
| IF(AV) (A) | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 |
| VF at 3A (mV, typ) | 450 | 450 | 450 | 450 | 480 | 500 |
| Automotive Grade (AEC-Q101) | No (commercial grade) | No | Yes | Yes | No | No |
| Lead-Free / RoHS | Yes | No (SnPb finish) | Yes | Yes | Yes | Yes |
Diferenciadores clave
- Wide distributor availability and active product life cycle (frente a SS34 (Vishay))
- Lower forward voltage drop at 3 A (frente a B340A-13-F (Diodes Incorporated))
- Optional AEC-Q101 automotive grade on the same die (frente a SS34 (Vishay))
Notas de diseño
At IF=3 A continuous with VF=450 mV typical, the MBRA340T3G dissipates roughly 1.35 W. Estimated: assuming theta_JA near 80 C/W on a 1 oz copper 1 sq inch SMA pad (standard JEDEC test board), the junction rises about 108 C above 25 C ambient, exceeding the 125 C rating. For continuous 3 A operation, use a 2 sq inch copper pour or forced-air cooling to keep Tj below 110 C. Above 2 A continuous, the SMA package becomes the thermal bottleneck before the silicon die.
Use a minimum 1 sq inch (645 sq mm) copper pad on the SMA cathode land to spread heat from the die to the PCB. The cathode lead is the thermal pad in the SMA package; the anode lead provides minimal thermal relief. Vias under the cathode land (4-8 x 0.3 mm thermal vias) to an internal copper plane can cut theta_JA by 30-40% in production boards. Avoid running high-current traces under the package to prevent additional heating.
Do not use MBRA340T3G on a 48 V telecom bus or any rail where transients exceed 40 V - the device has no avalanche rating and will fail short. Reverse leakage rises sharply with temperature (typically 20 mA at 25 C, but several hundred mA at 125 C), so always evaluate worst-case IR at the maximum operating junction temperature, not at 25 C. Do not parallel two MBRA340T3G without ballast resistors or matched thermal coupling - the negative temperature coefficient of VF can cause thermal runaway and current hogging.
Keep the MBRA340T3G loop area minimal in switching applications to limit inductive ringing. For a buck converter freewheeling diode, place the diode within 5 mm of the synchronous switch node and the output capacitor. In reverse-polarity protection circuits, place the diode immediately after the input connector and before any bulk capacitance to limit fault current. The SMA package polarity band must be oriented correctly; reversing it will short the input supply.
Información de cumplimiento
RoHS / lead-free confirmed by onsemi product page. The 'G' suffix designates Pb-free / RoHS compliance. Commercial grade only - use NRVBA340T3G for AEC-Q101 automotive qualification. Halogen-free status not explicitly stated in the verified data.
