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Taiwan Semiconductor Corporation SMBJ85CAH
- Part No.:
- SMBJ85CAH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ85CAH.pdf
- Description:
- TVS DIODE 85VWM 137VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:8,124
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Product details
Overview
SMBJ85CAH 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 power rails. It features a 85 V working stand-off voltage (VWM), 94.4–104 V breakdown voltage (VBR), 137 V maximum clamping voltage (VC) at 4.6 A peak impulse current (IPP), and 600 W peak pulse power rating with sub-1 ps response time.
For engineers reviewing the SMBJ85CAH datasheet, SMBJ85CAH pinout, SMBJ85CAH application, or SMBJ85CAH equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, AEC-Q101 qualification status, unidirectional vs. bidirectional configuration, thermal resistance (RθJA = 55 °C/W), and leakage current (<1 µA at 85 V).
Technical Context
The SMBJ85CAH is a glass-passivated, bipolar junction TVS diode optimized for fast transient suppression in 12 V and 24 V automotive subsystems. Its bidirectional architecture enables symmetrical clamping across both polarities without external polarity management, supporting robust protection of CAN, LIN, and sensor interfaces against EFT and load-dump events.
It operates within –55 °C to +150 °C junction temperature range and meets JESD201 Class 2 whisker resistance and J-STD-020 Moisture Sensitivity Level 1. Thermal performance is defined by RθJC = 10 °C/W and RθJA = 55 °C/W, enabling reliable operation under sustained ambient conditions up to 125 °C with appropriate PCB copper area.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 85 V - Maximum continuous DC or RMS voltage the device blocks without conduction |
| VBR min / max | 94.4 V / 104 V @ IT = 1 mA - Ensures predictable turn-on margin above system operating voltage |
| VC @ IPP | 137 V @ IPP = 4.6 A (10/1000 µs) - Limits downstream voltage stress during worst-case transients |
| PPK | 600 W - Sustains high-energy surges per ISO 7637-2 without degradation |
| ID @ VWM | <1 µA - Minimizes standby power loss and avoids false triggering in low-current circuits |
| Response time | <1.0 ps - Clamps before transient energy couples into protected ICs |
| TJ max | +150 °C - Supports under-hood automotive placement with full derating compliance |
Pinout & Package
DO-214AA (SMB) surface-mount package with cathode band marking; bidirectional configuration means both terminals are electrically symmetric - no anode/cathode assignment required. Matte tin-plated leads comply with J-STD-002 solderability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Bidirectional terminal A | Functions identically as either anode or cathode depending on transient polarity; no PCB polarity orientation needed |
| Terminal 2 | Bidirectional terminal B | Paired with Terminal 1 to form symmetrical clamping path; supports ±137 V clamping envelope |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan |
| ISO 7637-2 compliant | Withstands Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (EFT) waveforms without failure |
| Glass passivated junction | Enhances long-term stability and moisture resistance versus epoxy-passivated alternatives |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for environmentally constrained applications |
| Moisture sensitivity level 1 | Zero bake requirement prior to reflow; compatible with standard SMT assembly processes |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Protecting 12 V CAN FD bus lines and microcontroller GPIOs from load-dump and battery reverse-connection transients. IC Role / Device Role / Timing Role: Bidirectional clamping element placed directly at connector entry point to limit line voltage to ≤137 V during ISO 7637-2 Pulse 5a events. Use Value: Enables single-device protection without polarity-sensitive layout, reducing BOM count and PCB real estate vs. dual-unidirectional solutions. |
Use Scenario: Safeguarding 24 V digital input channels in programmable logic controllers exposed to inductive kickback from solenoid valves. IC Role / Device Role / Timing Role: Fast-response shunt clamp that diverts >4.6 A surge current away from input conditioning circuitry during switch-off events. Use Value: Maintains signal integrity by clamping within 1 ps, preventing latch-up or damage to upstream optocouplers and level translators. |
| LED Headlamp Driver Power Rail | Smart Sensor Node ESD Protection |
Use Scenario: Suppressing switching noise and load-dump spikes on constant-current LED driver supply rails in automotive headlamps. IC Role / Device Role / Timing Role: Primary overvoltage protector placed between DC/DC converter output and LED string, rated for 600 W peak pulse power. Use Value: Prevents catastrophic failure of high-brightness LEDs and driver ICs during cold-crank or jump-start conditions where rail voltage exceeds 100 V. |
Use Scenario: Shielding I²C and analog sensor interfaces (e.g., temperature, pressure) from human-body-model (HBM) and IEC 61000-4-2 contact ESD events. IC Role / Device Role / Timing Role: Low-leakage (≤1 µA) bidirectional TVS placed adjacent to connector pins to shunt ±8 kV ESD pulses before reaching ASIC inputs. Use Value: Preserves measurement accuracy by avoiding forward conduction during normal operation while clamping transients below IC absolute maximum ratings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ85CA | Same DO-214AC (SMA) package; 137 V VC @ 4.6 A but higher RθJA (65 °C/W); not AEC-Q101 qualified | Limited to commercial/industrial use; unsuitable for automotive under-hood deployment due to qualification gap | Select only if AEC-Q101 is not required and thermal margin allows higher junction rise |
| ON Semiconductor SMCJ85CA | DO-214AB (SMC) package; 137 V VC @ 4.6 A; AEC-Q101 qualified; 1.5× larger footprint than SMBJ85CAH | Higher power handling (1500 W) but requires more PCB area; better for systems needing extended surge endurance | Choose when board space permits and higher PPK margin is prioritized over miniaturization |
Compared with SMAJ85CA and SMCJ85CA, SMBJ85CAH delivers AEC-Q101 compliance in the smallest qualified DO-214AA footprint, enabling compact, automotive-grade protection where thermal constraints and layout density are critical.
Availability
SMBJ85CAH is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC input modules, LED lighting drivers, and smart sensor nodes requiring stable component supply across multi-year production cycles.
Supply support for SMBJ85CAH 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 validation capability.
The SMBJH series was developed specifically for automotive and industrial transient suppression, emphasizing fast response, low leakage, and robust packaging to meet stringent ISO 7637-2 and AEC-Q101 requirements.
FAQ
What does the 'CAH' suffix indicate in SMBJ85CAH?
The 'CAH' suffix denotes a bidirectional configuration with AEC-Q101 qualification and halogen-free construction. Unlike unidirectional variants (e.g., SMBJ85H), SMBJ85CAH provides symmetrical clamping for both positive and negative transients without polarity-dependent mounting - essential for protecting differential buses like CAN or analog sensor inputs where voltage polarity reverses.
Is SMBJ85CAH suitable for ISO 7637-2 Pulse 5a (load dump) protection?
Yes, SMBJ85CAH is explicitly tested and rated for ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b. While Pulse 5a (load dump) demands higher energy handling, SMBJ85CAH's 600 W PPK rating and 137 V clamping voltage make it appropriate for secondary protection stages or lower-energy load-dump scenarios in 12 V systems - primary protection may require higher-power devices like SMCJ or 5.0SMDJ series.
How does SMBJ85CAH differ from SMBJ85AH?
SMBJ85AH is unidirectional with a cathode band marking and forward voltage drop (~3.5 V), whereas SMBJ85CAH is bidirectional with no polarity marking and symmetrical clamping behavior. SMBJ85CAH replaces two unidirectional devices in differential applications, simplifying layout and eliminating risk of incorrect orientation during assembly - a key advantage in automated SMT lines.
What is the maximum allowable PCB trace length between SMBJ85CAH and protected IC?
To preserve sub-1 ps response, PCB trace inductance must be minimized: recommended trace length is ≤5 mm with ≥0.5 mm width and direct connection to ground plane. Longer traces increase impedance and delay clamping action, potentially allowing transient overshoot beyond SMBJ85CAH's 137 V VC rating - especially critical for high-speed interfaces like CAN FD or USB.
Does SMBJ85CAH require derating at elevated ambient temperatures?
Yes, SMBJ85CAH must be derated per Figure 2 in the datasheet: at 125 °C ambient, its 600 W peak pulse power drops to ~360 W (60% of rated value). This is due to junction temperature limits (TJ max = 150 °C) and RθJA = 55 °C/W. Designers must verify worst-case thermal environment and adjust surge duty cycle or add copper pour to maintain safe TJ margins.
SMBJ85CAH 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):
- 85V
- Voltage - Breakdown (Min):
- 94.4V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 4.6A
- 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)
SMBJ85CAH FAQ
1.How can I place an order for SMBJ85CAH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ85CAH 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 SMBJ85CAH reliable?
The price and inventory of SMBJ85CAH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ85CAH is usually 5 days.
3.What payment methods are accepted for SMBJ85CAH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ85CAH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ85CAH?
SMBJ85CAH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ85CAH 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 SMBJ85CAH?
For technical support, including SMBJ85CAH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ85CAH requirements.
6.How does Aetrix verify that SMBJ85CAH is sourced from the original manufacturer or authorized distributors?
All SMBJ85CAH 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 SMBJ85CAH meets industry standards.
7.What is the process for return or replacement of SMBJ85CAH?
All SMBJ85CAH units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ85CAH, 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 SMBJ85CAH part is unused and in its original packaging.
Return procedure for SMBJ85CAH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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