My Inquiry
My Account
Taiwan Semiconductor Corporation SMBJ85A
- Part No.:
- SMBJ85A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ85A.pdf
- Description:
- TVS DIODE 85VWM 137VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,500
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMBJ85A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, designed for high-energy surge protection in DC power rails and signal lines. 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 pulse current (IPP), and 600 W peak pulse power rating with sub-1 ps response time - deployed in automotive power supply inputs and industrial PLC I/O modules.
For engineers reviewing the SMBJ85A datasheet, SMBJ85A pinout, SMBJ85A application, or SMBJ85A equivalent, key selection criteria include clamping voltage margin relative to protected IC's absolute maximum rating, leakage current at operating voltage, thermal derating above 25°C ambient, and compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive transients.
Technical Context
The SMBJ85A operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its specified VBR range (94.4–104 V @ 1 mA). Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1 µA at 85 V), while the DO-214AA package provides robust thermal performance (RθJA = 55°C/W) and JESD201 Class 2 whisker resistance.
It delivers 600 W non-repetitive peak pulse power under 10/1000 µs waveform, with clamping voltage tightly controlled at 137 V max during 4.6 A surge - enabling reliable protection of 100 V-rated downstream components without overstress. The device meets ISO 7637-2 for automotive load-dump and inductive-switching immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 85 V - Maximum continuous reverse operating voltage before conduction begins; sets upper limit for protected circuit's normal DC rail. |
| VBR min/max | 94.4 / 104 V @ 1 mA - Confirmed breakdown threshold range; ensures predictable turn-on margin above VWM for noise immunity. |
| VC @ IPP | 137 V @ 4.6 A - Clamped voltage during full 600 W surge; must remain below protected IC's absolute maximum rating. |
| IPP | 4.6 A - Peak surge current supported at rated clamping voltage; defines minimum system-level surge energy handling (10/1000 µs). |
| IR @ VWM | <1 µA - Reverse leakage at 85 V; negligible power loss and no measurable loading on 85 V supply rails. |
| PPK | 600 W - Non-repetitive peak pulse power capability; validates suitability for ISO 7637-2 Pulse 1 (inductive switch-off) and Pulse 2b (battery dump). |
| TJ max | +150°C - Maximum junction temperature; supports operation in under-hood automotive environments and enclosed industrial enclosures. |
Pinout & Package
DO-214AA (SMB) surface-mount package with cathode band marking; matte tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 2 whisker resistance. Case meets UL 94V-0 flammability rating. Weight: 0.090 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path); enables unidirectional clamping from cathode to anode during overvoltage events. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., +85 V rail); conducts avalanche current to anode when reverse voltage exceeds VBR, limiting VC to 137 V. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable, repeatable VBR across temperature and lifetime; eliminates parameter drift due to moisture or contamination. |
| Sub-1 ps response time | Clamps transients before sensitive logic or analog circuits experience damaging overvoltage - critical for CAN/LIN bus and microcontroller I/O protection. |
| ISO 7637-2 compliance | Validated for automotive-grade immunity testing (Pulse 1, 2a, 2b, 3a, 3b); eliminates need for additional external filtering in vehicle ECU designs. |
| Moisture sensitivity level 1 | Zero bake requirement before reflow; compatible with standard SMT assembly processes without floor-life constraints. |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive; supports environmental compliance for global OEM and industrial certifications. |
Applications
| Automotive Power Input Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12 V/24 V battery-fed ECUs exposed to load dump (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and input filter capacitor to clamp surges before DC-DC converter. Use Value: Limits clamped voltage to 137 V, protecting 100 V-input buck controllers and ensuring system survival per ISO 16750-2. |
Use Scenario: 24 V digital input channels in programmable logic controllers subjected to inductive kickback from solenoid drivers. IC Role / Device Role / Timing Role: TVS mounted at field-side connector to shunt transient energy before optocoupler or Schmitt trigger input stage. Use Value: Sub-1 ps response prevents false triggering or latch-up in input conditioning circuitry during 100 ns–1 µs fast transients. |
| LED Driver Power Stage Protection | Telecom DC Power Feeds |
Use Scenario: Constant-current LED drivers in streetlight systems experiencing lightning-induced surges on AC-DC front-end outputs. IC Role / Device Role / Timing Role: TVS placed across output capacitors to absorb 600 W surge energy without degrading driver MOSFET gate oxide. Use Value: 137 V clamping voltage stays within 80% of typical 150 V-rated power FET VDS(max), preventing avalanche failure. |
Use Scenario: -48 V telecom power distribution boards exposed to EFT bursts (IEC 61000-4-4) and lightning-induced common-mode surges. IC Role / Device Role / Timing Role: Unidirectional TVS on each -48 V feed to protect upstream DC-DC converters and monitoring ICs. Use Value: <1 µA leakage at -48 V avoids unnecessary standby current draw; DO-214AA footprint fits dense backplane layouts. |
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 SMAJ85A | Same DO-214AC (SMA) package; 137 V VC @ 4.6 A; slightly higher RθJA (65°C/W) vs. SMBJ85A's 55°C/W. | Lower power density due to smaller SMA package; less suitable for sustained surge duty cycles in high-ambient environments. | Select SMBJ85A when thermal management is critical (e.g., sealed enclosures >70°C ambient); SMAJ85A acceptable for lower-duty-cycle applications. |
| ON Semiconductor SMCJ85A | DO-214AB (SMC) package; same 85 V VWM and 137 V VC, but rated for 1500 W PPK and 10.3 A IPP - larger footprint and higher cost. | Over-specified for 600 W requirements; introduces unnecessary PCB area and BOM cost where SMBJ85A's 600 W rating suffices. | Choose SMBJ85A for cost-optimized, space-constrained designs meeting ISO 7637-2 Pulse 2b/3b; reserve SMCJ85A only for multi-pulse or higher-energy threat profiles. |
Compared with SMAJ85A and SMCJ85A, the SMBJ85A offers optimal balance of surge capability (600 W), thermal performance (55°C/W), and compact DO-214AA footprint - making it preferred for automotive body control modules and industrial I/O where board space and thermal headroom are constrained.
Availability
SMBJ85A is available at Aetrix Electronics and suitable for automotive electronics, industrial PLCs, and LED lighting systems requiring stable component supply with full traceability and lifecycle support.
Supply support for SMBJ85A 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 - headquartered in Hsinchu, Taiwan, with ISO 9001 and IATF 16949 certified operations.
The SMBJ series was developed specifically for AEC-Q101 qualified automotive transient suppression and industrial-grade surge immunity, targeting applications demanding high reliability, low leakage, and standardized DO-214AA packaging.
FAQ
What is the clamping voltage of SMBJ85A and why does it matter?
The SMBJ85A has a maximum clamping voltage (VC) of 137 V at 4.6 A peak pulse current (IPP). This value is critical because it defines the highest voltage imposed on the protected circuit during a surge event - ensuring downstream components like DC-DC controllers or microcontrollers with 100 V absolute maximum ratings remain within safe operating limits. The 137 V clamping is validated under the standardized 10/1000 µs waveform per ANSI/IEEE C62.35.
Is SMBJ85A unidirectional or bidirectional, and how is polarity identified?
SMBJ85A is a unidirectional TVS diode, intended for DC line protection where polarity is fixed. Polarity is marked by a cathode band on the DO-214AA package body - the banded end connects to the protected line (e.g., +85 V rail), while the unbanded end connects to ground or return. Bidirectional variants use "C" or "CA" suffixes (e.g., SMBJ85CA), which are not applicable to SMBJ85A.
Does SMBJ85A meet automotive transient standards such as ISO 7637-2?
Yes, SMBJ85A is explicitly rated to meet ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a (sudden load removal), Pulse 2b (power supply disconnection), Pulse 3a (capacitive coupling), and Pulse 3b (ground noise) - confirmed in Taiwan Semiconductor's official documentation (Version R2104). This makes it suitable for engine control units, body control modules, and infotainment power supplies.
What is the maximum leakage current of SMBJ85A at its working voltage?
The SMBJ85A exhibits a maximum blocking leakage current (ID) of less than 1 µA at its 85 V working stand-off voltage (VWM), measured at 25°C ambient. This ultra-low leakage ensures minimal power loss and zero loading effect on 85 V supply rails - essential for battery-powered or energy-sensitive systems where standby current must be minimized.
Can SMBJ85A be used in place of SMBJ85 without redesigning the PCB layout?
Yes, SMBJ85A and SMBJ85 share identical DO-214AA (SMB) package dimensions, pinout, and thermal pad layout - they differ only in breakdown voltage tightness (SMBJ85A has tighter VBR tolerance: 94.4–104 V vs. SMBJ85's 94.4–115 V) and slightly lower clamping voltage (137 V vs. 151 V). No PCB changes are required for drop-in replacement, and SMBJ85A provides improved voltage margin for precision protection.
SMBJ85A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 85V
- Voltage - Breakdown (Min):
- 94.4V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 4.4A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ85A FAQ
1.How can I place an order for SMBJ85A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ85A 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 SMBJ85A reliable?
The price and inventory of SMBJ85A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ85A is usually 5 days.
3.What payment methods are accepted for SMBJ85A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ85A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ85A?
SMBJ85A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ85A 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 SMBJ85A?
For technical support, including SMBJ85A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ85A requirements.
6.How does Aetrix verify that SMBJ85A is sourced from the original manufacturer or authorized distributors?
All SMBJ85A 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 SMBJ85A meets industry standards.
7.What is the process for return or replacement of SMBJ85A?
All SMBJ85A units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ85A, 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 SMBJ85A part is unused and in its original packaging.
Return procedure for SMBJ85A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ85A 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…
