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Taiwan Semiconductor Corporation SMBJ40CH
- Part No.:
- SMBJ40CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ40CH.pdf
- Description:
- 600W, 49.4V, 10%, BIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:9,208
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Product details
Overview
SMBJ40CH from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, designed for high-energy ESD and surge protection in automotive and industrial systems. It features a 40 V working stand-off voltage (VWM), 44.4–54.3 V breakdown voltage (VBR), 71.4 V maximum clamping voltage (VC) at 8.8 A peak pulse current, and 600 W peak pulse power rating with sub-1 ps response time.
For engineers reviewing the SMBJ40CH datasheet, SMBJ40CH pinout, SMBJ40CH application, or SMBJ40CH equivalent, key selection criteria include unidirectional vs. bidirectional configuration (CH suffix denotes bidirectional), clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, leakage current ≤1 µA at 40 V, and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
The SMBJ40CH implements a glass-passivated silicon junction optimized for fast transient suppression in both polarities. Its bidirectional architecture enables symmetrical clamping without external polarity management, supporting compliance with ISO 7637-2 Pulse 1 (inductive load dump), Pulse 2a/2b (battery disconnection), and Pulse 3a/3b (capacitive coupling transients).
Thermal design is enabled by RθJC = 10 °C/W and RθJA = 55 °C/W, allowing sustained operation up to TJ = 150 °C. The device sustains 100 A non-repetitive forward surge (IFSM) and maintains <3.5 V forward voltage only in unidirectional variants - not applicable to SMBJ40CH due to its bidirectional construction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse voltage before clamping initiates; defines operating margin below breakdown |
| VBR min / max | 44.4 V / 54.3 V - Breakdown occurs within this range at 1 mA test current; ensures predictable turn-on threshold |
| VC @ IPP | 71.4 V at 8.8 A - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to safe levels |
| PPK | 600 W - Peak pulse power handling per 10/1000 µs waveform; supports robust ISO 7637-2 immunity |
| ID @ VWM | ≤1 µA - Leakage current at rated stand-off voltage; minimizes standby power loss in battery systems |
| Response time | <1.0 ps - Junction-level reaction speed; ensures clamping before transient energy couples into circuitry |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive environments |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, bi-directional configuration with cathode band omitted (no polarity marking required). Matte tin-plated leads, moisture sensitivity level 1 (J-STD-020), UL 94V-0 molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche junction | No fixed anode/cathode; terminals interchangeable; clamps equally on positive or negative transients |
| Cathode band (absent) | Polarity indicator | Not present - confirms bidirectional construction; eliminates risk of incorrect orientation during placement |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control, body electronics, and ADAS sensor interfaces |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive switch-off), Pulse 2a/2b (battery interruption), and Pulse 3a/3b (line impedance coupling) |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal cycling and humidity stress |
| Sub-1 ps response time | Enables clamping before transient energy propagates beyond PCB trace inductance, protecting high-speed interfaces |
| DO-214AA (SMB) footprint | Standardized 4.58 × 3.94 mm outline compatible with automated SMT assembly and IPC-7351B land patterns |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting LIN/CAN bus nodes and power inputs in vehicle body control modules against load dump and jump-start surges. IC Role / Device Role / Timing Role: Bidirectional TVS placed at connector entry point to clamp ±100 V transients before reaching transceiver ICs and microcontrollers. Use Value: Limits clamped voltage to 71.4 V while absorbing 600 W pulses, preventing latch-up or gate oxide damage in 5 V/3.3 V logic. | Use Scenario: Safeguarding analog front-ends of pressure, temperature, and current sensors in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Front-line transient suppressor on 24 V supply rails and signal lines exposed to relay coil kickback and EFT bursts. Use Value: Sub-1 ps response ensures clamping precedes propagation delay of op-amps and ADC drivers, preserving measurement integrity. |
| LED Lighting Driver Protection | ESD-Sensitive Communication Port Protection |
Use Scenario: Shielding constant-current LED drivers in automotive headlamps and street lighting from inductive switching transients. IC Role / Device Role / Timing Role: Parallel-connected TVS across driver output to absorb energy from inductive ballast or MOSFET turn-off spikes. Use Value: 600 W PPK rating handles repetitive 10/1000 µs surges common in PWM-driven inductive loads without degradation. | Use Scenario: Hardening RS-485, USB, or Ethernet PHY ports in medical and test equipment against human-body-model (HBM) ESD events. IC Role / Device Role / Timing Role: Low-capacitance bidirectional clamp on differential pairs to suppress ±15 kV contact discharge without distorting signal edges. Use Value: ≤1 µA leakage at 40 V prevents DC bias shift in precision termination networks; symmetrical clamping avoids common-mode skew. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ40CA | Identical VWM (40 V), VBR (44.4–54.3 V), VC (71.4 V), and package; same AEC-Q101 qualification and ISO 7637-2 compliance | No functional difference; CA suffix is alternate manufacturer marking for same bidirectional SMBJ40 specification | Select SMBJ40CA if dual-sourcing or second-source validation is required; identical electrical and mechanical behavior |
| SMCJ40CA | Same VWM/VBR/VC ratings but in larger DO-214AB (SMC) package; higher PPK = 1500 W; RθJA = 35 °C/W vs. 55 °C/W | Higher power handling suits infrequent high-energy surges (e.g., lightning-induced); less suitable for space-constrained automotive ECUs | Choose SMCJ40CA where board area allows and surge threat level exceeds 600 W; otherwise SMBJ40CH offers optimal density-to-protection ratio |
Compared with SMBJ40CA, SMBJ40CH offers identical protection performance in the same footprint; versus SMCJ40CA, it trades 2.5× peak power for 40% smaller PCB area and faster thermal response in compact enclosures.
Availability
SMBJ40CH is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, LED lighting drivers, and ESD-sensitive communication ports requiring stable component supply across production lifecycles.
Supply support for SMBJ40CH 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101-compliant production lines.
The SMBJH series was developed specifically for automotive and industrial transient suppression, emphasizing AEC-Q101 reliability, ISO 7637-2 compliance, and surface-mount scalability in the DO-214AA footprint.
FAQ
What does the 'CH' suffix indicate in SMBJ40CH?
The 'CH' suffix in SMBJ40CH denotes a bidirectional TVS diode configuration. Unlike unidirectional variants (e.g., SMBJ40H), SMBJ40CH provides symmetrical clamping for both positive- and negative-polarity transients without requiring polarity-aware PCB layout. This makes SMBJ40CH ideal for AC-coupled lines, differential buses, and applications where voltage polarity reversal is possible. The device has no cathode marking, confirming its bidirectional nature.
Is SMBJ40CH qualified for automotive applications?
Yes, SMBJ40CH is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements. Its glass-passivated junction, 150 °C maximum junction temperature, and moisture sensitivity level 1 (J-STD-020) support deployment in under-hood and chassis-mounted automotive modules. Taiwan Semiconductor's production line for SMBJ40CH follows automotive-specific process controls and lot traceability protocols.
What is the maximum clamping voltage of SMBJ40CH and at what current is it specified?
The maximum clamping voltage (VC) of SMBJ40CH is 71.4 V, measured at a peak pulse current (IPP) of 8.8 A using the standardized 10/1000 µs double-exponential waveform. This value is guaranteed across the full operating temperature range and represents the upper limit of voltage seen by protected circuitry during worst-case surge events. It is derived from the device's intrinsic avalanche characteristics and package parasitics.
How does SMBJ40CH compare to SMBJ40AH in terms of electrical performance?
SMBJ40CH is bidirectional with symmetric VBR (44.4–54.3 V) and VC (71.4 V), while SMBJ40AH is unidirectional with lower VBR (44.4–49.1 V) and reduced VC (64.5 V) at 9.7 A. SMBJ40AH exhibits slightly better clamping efficiency but requires correct polarity orientation and cannot suppress negative transients. SMBJ40CH sacrifices ~10% clamping voltage headroom for polarity-agnostic protection - critical in differential or floating systems where ground reference is unstable.
Can SMBJ40CH be used in place of SMBJ40H on an existing PCB?
No - SMBJ40H is unidirectional and marked with a cathode band; replacing it with bidirectional SMBJ40CH removes polarity dependency but alters the clamping curve symmetry and may increase leakage under DC bias in certain topologies. While both share the DO-214AA package and pin-compatible footprint, the functional difference affects system-level surge response. Redesign verification is required, especially in circuits relying on unidirectional blocking or forward conduction paths.
SMBJ40CH 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 71.4V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- 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)
SMBJ40CH FAQ
1.How can I place an order for SMBJ40CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ40CH 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 SMBJ40CH reliable?
The price and inventory of SMBJ40CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ40CH is usually 5 days.
3.What payment methods are accepted for SMBJ40CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ40CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ40CH?
SMBJ40CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ40CH 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 SMBJ40CH?
For technical support, including SMBJ40CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ40CH requirements.
6.How does Aetrix verify that SMBJ40CH is sourced from the original manufacturer or authorized distributors?
All SMBJ40CH 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 SMBJ40CH meets industry standards.
7.What is the process for return or replacement of SMBJ40CH?
All SMBJ40CH units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ40CH, 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 SMBJ40CH part is unused and in its original packaging.
Return procedure for SMBJ40CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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