My Inquiry
My Account
Taiwan Semiconductor Corporation SMBJ18H
- Part No.:
- SMBJ18H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ18H.pdf
- Description:
- 600W, 22.2V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:2,806
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMBJ18H from Taiwan Semiconductor is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, with 18 V working stand-off voltage (VWM), 20.0–24.4 V breakdown voltage (VBR), and 32.2 V maximum clamping voltage (VC) at 19.5 A peak pulse current - designed for automotive ECU power rail and CAN bus line protection against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMBJ18H datasheet, SMBJ18H pinout, SMBJ18H application, or SMBJ18H equivalent, key selection criteria include clamping performance under 10/1000 µs surge, leakage current ≤1 µA at 18 V, AEC-Q101 qualification, and compatibility with automated SMT placement on 12 V automotive subsystems.
Technical Context
The SMBJ18H operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its 20.0–24.4 V breakdown threshold (tested at 1 mA), clamping transients to ≤32.2 V at 19.5 A (10/1000 µs waveform). Its glass-passivated junction ensures stable VBR tolerance and low leakage (<1 µA at VWM = 18 V).
Thermal design relies on RθJC = 10 °C/W and RθJA = 55 °C/W, enabling 3 W steady-state dissipation at 25 °C ambient. It meets JESD201 Class 2 whisker resistance and J-STD-020 Moisture Sensitivity Level 1 - supporting reflow-compatible assembly without pre-baking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before conduction begins; sets minimum system overvoltage immunity margin. |
| VBR min/max | 20.0 / 24.4 V @ 1 mA - Confirmed breakdown range ensures reliable turn-on across temperature and process variation. |
| VC @ IPP | 32.2 V @ 19.5 A (10/1000 µs) - Clamping voltage defines worst-case stress on downstream ICs during surge events. |
| PPK | 600 W - Peak pulse power rating determines survivability of high-energy transients like load dump or inductive kick. |
| ID @ VWM | <1 µA - Ultra-low leakage preserves battery life and avoids false triggering in always-on automotive modules. |
| TJ max | +150 °C - Junction temperature limit supports operation in under-hood environments with minimal derating. |
Pinout & Package
DO-214AA (SMB) surface-mount package with cathode band marking; matte tin-plated leads compliant with J-STD-002 solderability; polarity-sensitive unidirectional configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Ground reference terminal | Connected to system ground or low-side return path; forms current loop during clamping. |
| Cathode | Protected line input | Connected to protected signal/power line (e.g., 12 V rail); conducts surge current to ground when VAK > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan. |
| Glass passivated junction | Ensures stable VBR drift <±5% over lifetime and eliminates moisture-induced parameter shift in humid environments. |
| Fast response time | Typically <1.0 ps - enables clamping before sensitive logic or analog circuitry sustains damage from EFT or ESD. |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (EFT) waveforms without degradation. |
Applications
| Automotive Power Rail Protection | CAN Bus Line Protection |
|---|---|
Use Scenario: 12 V battery-fed ECU power input subjected to load dump (up to 40 V) and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and GND to clamp surges before they reach LDOs or microcontrollers. Use Value: Limits voltage excursion to ≤32.2 V during 600 W transients, preserving 3.3 V/5 V regulator input integrity and preventing latch-up. | Use Scenario: High-speed CAN FD transceiver lines exposed to ESD (IEC 61000-4-2) and coupled noise from adjacent power traces. IC Role / Device Role / Timing Role: Bidirectional protection not applicable - SMBJ18H used on single-ended supply rails feeding CAN PHY, not differential bus lines. Use Value: Sub-µA leakage avoids signal distortion; 32.2 V clamping protects 5 V CAN controller VCC pins during ISO 7637-2 Pulse 2a events. |
| Industrial Sensor Interface Protection | LED Driver Input Stage Protection |
Use Scenario: 24 V industrial I/O module with analog sensor inputs sharing common power rail vulnerable to field wiring transients. IC Role / Device Role / Timing Role: Primary rail-level TVS upstream of DC-DC converter and signal conditioning circuitry. Use Value: Withstands repeated 10/1000 µs surges up to 19.5 A while maintaining <1 µA standby leakage - critical for low-power remote sensors. | Use Scenario: Constant-current LED driver input connected to unregulated 12–24 V supply subject to inductive switching noise from relay coils or solenoids. IC Role / Device Role / Timing Role: Standoff-rated suppression device placed at driver IC VIN pin to absorb energy from back-EMF spikes. Use Value: 600 W PPK rating handles repetitive 100 ms inductive kicks; DO-214AA footprint allows compact layout near connector entry point. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18A | Lower VBR range (20.0–22.1 V) and lower VC (29.2 V @ 21.5 A); same PPK and package. | Better clamping ratio (VC/VBR ≈ 1.31 vs. 1.39), suited for tighter voltage margins downstream. | Select SMBJ18A when downstream IC absolute maximum ratings require sub-30 V clamping under full 600 W surge. |
| SAC18 | Same VWM (18 V), but bidirectional configuration; higher VC (35.5 V @ 17.7 A); smaller DO-214AC (SMC) package. | Supports AC-coupled or dual-polarity lines; requires PCB redesign due to larger pad area and different thermal profile. | Choose SAC18 only if bipolar protection is required and board space allows SMC footprint; otherwise SMBJ18H remains optimal for unidirectional 12 V rails. |
Compared with SMBJ18A and SAC18, the SMBJ18H offers the highest clamping voltage among 18 V unidirectional TVS diodes in DO-214AA, trading margin for robustness in high-energy transients - making it preferred for under-hood ECUs where surge amplitude outweighs tight clamping ratio requirements.
Availability
SMBJ18H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and LED driver input stages requiring stable component supply with AEC-Q101 qualification and ISO 7637-2 compliance.
Supply support for SMBJ18H 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated Taiwanese semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive and industrial markets.
The SMBJH series was developed specifically for AEC-Q101-compliant transient suppression in 12 V/24 V automotive subsystems, emphasizing low leakage, repeatable clamping, and SMT manufacturability.
FAQ
What is the maximum clamping voltage of SMBJ18H under standard 10/1000 µs surge conditions?
The SMBJ18H has a maximum clamping voltage (VC) of 32.2 V when subjected to a 19.5 A peak pulse current with a 10/1000 µs waveform. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during transient events - critical for ensuring downstream ICs remain within their absolute maximum ratings. The SMBJ18H maintains this clamping performance across its specified operating temperature range.
Is SMBJ18H suitable for bidirectional signal line protection such as RS-485 or CAN differential pairs?
No, SMBJ18H is a unidirectional TVS diode and is not suitable for bidirectional signal line protection. It conducts only when the cathode is positive relative to the anode, making it appropriate for DC power rail protection (e.g., 12 V supply to microcontroller), not AC or differential signals. For CAN or RS-485 lines, a bidirectional variant like SMBJ18CH or dedicated bidirectional array must be used - the SMBJ18H would fail to protect negative-going transients on such lines.
Does SMBJ18H meet automotive qualification standards required for engine control unit deployment?
Yes, SMBJ18H is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b transient immunity requirements. Its DO-214AA package passes JESD201 Class 2 whisker testing and J-STD-020 MSL Level 1, supporting lead-free reflow without preconditioning - fulfilling core reliability mandates for under-hood ECU applications. The SMBJ18H datasheet confirms these qualifications in Sections 1 and 4.
What is the leakage current specification for SMBJ18H at its rated working voltage?
The SMBJ18H exhibits a maximum blocking leakage current (ID) of 1 µA when biased at its 18 V working stand-off voltage (VWM), measured at TA = 25°C. This ultra-low leakage ensures minimal power loss in always-on automotive modules and prevents false triggering in high-impedance sensing circuits. The SMBJ18H maintains this specification across its full operating temperature range (-55°C to +150°C), as verified in TSC's electrical characterization data.
Can SMBJ18H be used in place of SMBJ18A in an existing design without layout changes?
Yes, SMBJ18H and SMBJ18A share identical DO-214AA (SMB) package dimensions, pinout, and solder pad requirements - enabling direct substitution without PCB modifications. However, SMBJ18H has a higher VBR range (20.0–24.4 V vs. 20.0–22.1 V) and higher clamping voltage (32.2 V vs. 29.2 V), which may affect system-level surge margin. Verify that downstream components tolerate the 3.0 V higher VC before replacing SMBJ18A with SMBJ18H in an existing design.
SMBJ18H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJH
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 32.2V
- Current - Peak Pulse (10/1000µs):
- 19.5A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ18H FAQ
1.How can I place an order for SMBJ18H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ18H 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 SMBJ18H reliable?
The price and inventory of SMBJ18H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ18H is usually 5 days.
3.What payment methods are accepted for SMBJ18H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ18H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ18H?
SMBJ18H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ18H 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 SMBJ18H?
For technical support, including SMBJ18H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ18H requirements.
6.How does Aetrix verify that SMBJ18H is sourced from the original manufacturer or authorized distributors?
All SMBJ18H 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 SMBJ18H meets industry standards.
7.What is the process for return or replacement of SMBJ18H?
All SMBJ18H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ18H, 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 SMBJ18H part is unused and in its original packaging.
Return procedure for SMBJ18H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ18H 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
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 …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
