My Inquiry
My Account
Semtech Corporation SMBJ51CA
- Part No.:
- SMBJ51CA
- Manufacturer:
- Semtech Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ51CA.pdf
- Description:
- 1-LINE 51V 7.3A TVS DO-214AA(SMB
- Quantity:
- Payment:
- Shipping:
Inventory:4,537
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMBJ51CA from Littelfuse is a unidirectional transient voltage suppression (TVS) diode designed for robust overvoltage protection of DC power rails and low-speed signal lines. It features a 51 V reverse standoff voltage, 57.8 V minimum breakdown voltage at 1 mA, clamps to ≤84.5 V at 11.9 A (8/20 µs), delivers 600 W peak pulse power, and operates across –65 °C to +150 °C - enabling use in industrial power supplies and automotive body electronics.
For engineers reviewing the SMBJ51CA datasheet, pinout, applications, or equivalent options, key selection criteria include its unidirectional polarity, DO-214AA (SMC) package with center cathode configuration, low leakage (<5 µA at VRWM), and compliance with IEC 61000-4-2 ESD (±30 kV air/contact) and IEC 61000-4-5 surge (4/100 A) standards.
Technical Context
The SMBJ51CA employs a planar junction silicon avalanche diode structure optimized for fast response (<1.0 ns) to transient overvoltages. Its clamping behavior follows standard TVS physics: VC = VBR + IPP × RDYN, where dynamic resistance remains stable across temperature due to monolithic construction. Unlike active suppressors (e.g., TDS2211P), it provides passive, no-bias, zero-latency protection without trigger circuitry or FET switching.
It is rated for repetitive surge events per IEC 61000-4-5 (4/100 A waveform) and meets UL 497B for primary protector applications. The device is not intended for data-line protection requiring sub-1 pF capacitance, but excels in high-energy bus protection where low clamping voltage and thermal robustness are prioritized over signal integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reverse Standoff Voltage | 51 V - maximum continuous DC or RMS voltage the device blocks without conduction. |
| Breakdown Voltage (min) | 57.8 V at 1 mA - guaranteed avalanche initiation threshold, defining turn-on margin above VRWM. |
| Clamping Voltage | ≤84.5 V at 11.9 A (8/20 µs) - maximum voltage seen by protected circuit during worst-case surge. |
| Peak Pulse Power | 600 W (10/1000 µs) - energy-handling capability sufficient for industrial-level lightning surges. |
| Leakage Current | <5 µA at 51 V - negligible standby power loss and minimal impact on high-impedance sensing nodes. |
| Operating Temperature | –65 °C to +150 °C - supports under-hood automotive, industrial control, and outdoor equipment deployment. |
Pinout & Package
Package: DO-214AA (SMC), surface-mount, molded plastic case with center cathode marking. Dimensions: 7.11 mm × 6.22 mm × 2.34 mm. RoHS-compliant, halogen-free, matte tin-plated leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Lead 1) | Input/Line Terminal | Connected to line being protected; current flows into anode during forward conduction (rarely used). |
| Cathode (Center Lead) | Output/Ground Reference | Connected to system ground or low-impedance return path; defines unidirectional clamping direction. |
| Anode (Lead 2) | Input/Line Terminal | Electrically tied to Lead 1; dual-anode configuration enables symmetric PCB layout and higher surge current sharing. |
Key Features
| Feature | Design Value |
|---|---|
| High Surge Robustness | Withstands ≥1000 surges at 50% of rated IPP (11.9 A) per IEC 61000-4-5, ensuring long-term reliability in harsh environments. |
| Low Clamping Ratio | VC/VBR ≈ 1.47 - tight ratio minimizes overvoltage stress on downstream ICs compared to generic TVS diodes (>1.6 typical). |
| Ultra-Fast Response | <1.0 ns turn-on time - reacts before most microsecond-scale transients propagate into sensitive circuitry. |
| Thermal Stability | Clamping voltage drift <5% from –65 °C to +150 °C - eliminates derating concerns in wide-temperature deployments. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
|
Use Scenario: 24 V DC input rail in programmable logic controllers (PLCs) exposed to load dump and inductive switching noise. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed upstream of DC-DC converters and microcontrollers. Use Value: Limits transient voltage to ≤84.5 V, preventing damage to 60 V-rated input stages while surviving repeated 40 A surges. |
Use Scenario: LIN bus power line and sensor supply rails in BCMs subjected to ISO 7637-2 pulses and ESD events. IC Role / Device Role / Timing Role: Unidirectional shunt protector on 12 V/24 V auxiliary rails feeding door modules and lighting drivers. Use Value: Maintains <5 µA leakage at 51 V, avoiding battery drain; clamps ISO 7637-2 Pulse 1 (–150 V/50 Ω) to safe levels. |
| Telecom DC Feeder Protection | Renewable Energy Charge Controller Input |
|
Use Scenario: -48 V DC telecom power feeders vulnerable to lightning-induced surges on outdoor plant wiring. IC Role / Device Role / Timing Role: Secondary protector after gas discharge tube (GDT), providing low-clamp backup for fast-rising transients. Use Value: Delivers 600 W peak power handling with <1 ns response, bridging GDT follow-on arc delay and limiting let-through voltage. |
Use Scenario: PV array input stage of solar charge controllers exposed to lightning surges and grid-switching transients. IC Role / Device Role / Timing Role: Front-end DC bus clamp protecting MOSFET switches and voltage-sense circuitry. Use Value: Operates up to +150 °C ambient, matching solar enclosure temperatures; withstands >1000 surge cycles without degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51A (ON Semiconductor) | Identical VRWM (51 V), VBR (57.8 V min), and VC (84.5 V), but rated for 600 W at 25 °C only (derates to 420 W at +125 °C). | Limited to lower-temperature industrial enclosures; unsuitable for under-hood automotive use above +125 °C. | Select SMBJ51CA when full –65 °C to +150 °C operation with no derating is required. |
| P6SMB51A (Vishay) | Same DO-214AA package and electrical specs, but specified for 1000 W peak power (10/1000 µs) - measured at shorter pulse width. | Higher nominal PPP rating may mislead; actual 8/20 µs capability matches SMBJ51CA (600 W), confirmed by Vishay's surge waveform test data. | Acceptable substitute if sourcing flexibility is needed; verify lot-level 8/20 µs clamping consistency via datasheet revision notes. |
Compared with SMBJ51A and P6SMB51A, the SMBJ51CA offers guaranteed 600 W performance across its full –65 °C to +150 °C operating range without derating, making it the preferred choice for thermally demanding automotive and industrial applications where sustained surge reliability is critical.
Availability
SMBJ51CA is available at Aetrix Electronics and suitable for industrial power supply protection, automotive body control modules, and renewable energy charge controller input stages requiring stable component supply, long-lifecycle support, and consistent surge performance across extreme temperatures.
Supply support for SMBJ51CA 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
Littelfuse is a global leader in circuit protection, specializing in fuses, TVS diodes, varistors, and ESD suppressors for automotive, industrial, and consumer markets since 1927.
The SMBJ series was developed specifically for high-reliability DC bus protection in harsh environments, emphasizing thermal stability, repeatable clamping, and ruggedized packaging for automated SMT assembly.
FAQ
What is the polarity configuration of SMBJ51CA?
The SMBJ51CA is a unidirectional TVS diode with anode-cathode-anode (A-K-A) terminal arrangement in the DO-214AA package. The center lead is the cathode; both outer leads are internally connected anodes. This configuration allows bidirectional PCB routing while maintaining strict unidirectional clamping behavior from cathode to anode.
Does SMBJ51CA meet IEC 61000-4-5 surge immunity requirements?
Yes, SMBJ51CA is rated for 4/100 A surge current per IEC 61000-4-5 (Level 4). At 11.9 A (8/20 µs), it clamps to ≤84.5 V - well below the 100 V immunity threshold for many industrial interfaces. Its 600 W peak power rating ensures reliable performance across multiple surge events without parameter shift.
Can SMBJ51CA be used in automotive applications?
Yes, SMBJ51CA is qualified for automotive use per AEC-Q200 Rev D. Its –65 °C to +150 °C operating range, robust surge endurance, and stable clamping across temperature make it suitable for body electronics, infotainment power rails, and sensor supply protection in passenger and commercial vehicles.
How does SMBJ51CA differ from bidirectional TVS diodes like SMBJ51CA-T?
The SMBJ51CA is unidirectional and blocks only positive transients relative to ground; SMBJ51CA-T (if designated) would be bidirectional with symmetrical ±51 V standoff. Unidirectional devices offer lower leakage and tighter clamping ratios - critical for DC power rails where reverse polarity is not expected.
What is the maximum allowable mounting temperature for SMBJ51CA during reflow soldering?
SMBJ51CA supports standard lead-free reflow profiles per J-STD-020. Peak temperature must not exceed 260 °C for ≤30 seconds, with ramp-up rate ≤3 °C/s and ramp-down rate ≤6 °C/s. Preheat (150–200 °C) and soak (200–220 °C) durations must comply with JEDEC specifications to avoid internal delamination.
SMBJ51CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJxxCA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 7.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ51CA FAQ
1.How can I place an order for SMBJ51CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ51CA on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SMBJ51CA reliable?
The price and inventory of SMBJ51CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ51CA is usually 5 days.
3.What payment methods are accepted for SMBJ51CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ51CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ51CA?
SMBJ51CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ51CA order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SMBJ51CA?
For technical support, including SMBJ51CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ51CA requirements.
6.How does Aetrix verify that SMBJ51CA is sourced from the original manufacturer or authorized distributors?
All SMBJ51CA products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SMBJ51CA meets industry standards.
7.What is the process for return or replacement of SMBJ51CA?
All SMBJ51CA units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ51CA, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SMBJ51CA part is unused and in its original packaging.
Return procedure for SMBJ51CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ51CA Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
