My Inquiry
My Account
Diodes Incorporated SMAJ78CA-13-F
- Part No.:
- SMAJ78CA-13-F
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ78CA-13-F.pdf
- Description:
- TVS DIODE 78VWM 126VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:210,739
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ78CA-13-F from Diodes Incorporated is a bidirectional 400W transient voltage suppressor (TVS) diode in SMA package, designed for primary overvoltage protection at DC power inputs and signal lines. It features 78V reverse standoff voltage (VRWM), 86.7–95.8V breakdown range (VBR), 126V max clamping voltage (VC) at 3.2A peak pulse current (IPP), and operates from –55°C to +150°C - deployed in automotive body control modules and industrial PLC I/O protection.
For engineers reviewing the SMAJ78CA-13-F datasheet, SMAJ78CA-13-F pinout, SMAJ78CA-13-F application, or SMAJ78CA-13-F equivalent, key selection criteria include clamping ratio (VC/VRWM = 1.61), unidirectional vs. bidirectional polarity configuration, thermal derating above +25°C, and compatibility with IATF 16949-manufactured AEC-Q200 variants (e.g., SMAJ78CAQ-13-F).
Technical Context
This bidirectional TVS uses glass-passivated junction construction to achieve sub-nanosecond response time and stable clamping under 8.3ms half-sine surge pulses. Its symmetrical avalanche structure enables equal clamping in both polarities, eliminating need for polarity-aware PCB layout in AC-coupled or floating bus applications.
Thermal performance is defined by 1.0W steady-state dissipation at TL = +75°C and full derating to zero at +150°C ambient. The device meets JEDEC J-STD-020 moisture sensitivity Level 1 and supports lead-free reflow per MIL-STD-202 Method 208.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W - sustains single 8.3ms surges up to 3.2A without failure |
| Reverse Standoff Voltage | 78V - maximum continuous DC or RMS voltage before significant leakage |
| Clamping Voltage | 126V @ IPP = 3.2A - limits downstream voltage stress during transients |
| Breakdown Voltage | 86.7–95.8V @ IT = 1mA - defines onset of avalanche conduction |
| Leakage Current | 5.0µA @ VRWM = 78V - ensures minimal standby power loss in high-impedance circuits |
| Operating Temp Range | –55°C to +150°C - validated for under-hood automotive and industrial environments |
Pinout & Package
Package: SMA (Surface Mount Assembly), molded plastic case per UL 94V-0, 0.064g mass, cathode band omitted (bidirectional device).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche terminals | No polarity marking; either terminal serves as anode or cathode depending on transient polarity |
| Case | Non-electrical mechanical interface | Plastic body provides insulation and thermal path to PCB copper; no internal connection |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse rating | Enables robust protection against IEC 61000-4-5 Level 4 (4kV/2Ω) surges without derating |
| Glass-passivated die | Ensures long-term stability of VBR and VC across temperature and life cycles |
| Bidirectional symmetry | Eliminates orientation constraints in AC line, RS-485, or CAN bus protection layouts |
| RoHS 3 & Halogen-Free | Complies with EU Directive 2015/863/EU and automotive green material requirements |
Applications
| Automotive Body Control Module | Industrial PLC Digital Input |
|---|---|
Use Scenario: Protects 12V battery-supplied microcontroller I/O pins from load dump and alternator ripple transients. IC Role / Device Role: Primary clamping element placed directly at connector entry point before ESD diode array. Use Value: Clamps 120V load dump spikes to ≤126V, preserving MCU GPIO integrity without series impedance. | Use Scenario: Shields 24V DC digital input channels from field-wiring induced surges in factory automation cabinets. IC Role / Device Role: Front-end transient suppressor mounted on DIN-rail I/O module PCB, upstream of optocoupler isolation. Use Value: Limits transient energy to <10mJ per pulse, preventing optocoupler CTR degradation and false triggering. |
| RS-485 Data Line Protection | DC Power Rail Clamp |
Use Scenario: Safeguards differential RS-485 transceivers connected to long outdoor cables exposed to lightning-induced surges. IC Role / Device Role: Bidirectional TVS placed across A/B lines and to ground, forming low-inductance clamp network. Use Value: Symmetric clamping maintains common-mode rejection while limiting differential overvoltage to <126V. | Use Scenario: Suppresses switching noise and inductive kickback on 48V telecom power distribution rails. IC Role / Device Role: Parallel-mounted TVS at DC-DC converter output to absorb transient energy from motor drivers or solenoids. Use Value: 126V clamping prevents overvoltage shutdown of downstream POL regulators rated for 50V max input. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78A-13-F | Unidirectional version; same VRWM, VBR, VC, and IPP ratings | Requires correct polarity placement; unsuitable for AC or floating-bus use | Select only when circuit topology guarantees fixed polarity and space allows orientation-aware layout |
| SMAJ78CAQ-13-F | AEC-Q200 qualified; manufactured in IATF 16949 facility; identical electrical specs | Required for automotive production programs with PPAP submission and change control | Specify for OEM Tier-1 BOMs where qualification traceability and automotive-grade sourcing are mandatory |
Compared with SMAJ78A-13-F, the bidirectional variant eliminates polarity dependency but trades off slightly higher capacitance; versus SMAJ78CAQ-13-F, it lacks automotive qualification documentation yet offers identical electrical performance for non-automotive industrial use.
Availability
SMAJ78CA-13-F is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O protection, RS-485 communication interfaces, and 48V DC power rail clamping requiring stable component supply across extended temperature ranges.
Supply support for SMAJ78CA-13-F 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.
The SMAJ series belongs to Diodes' transient voltage suppression product line, engineered specifically for high-energy surge immunity in harsh-environment applications including automotive, industrial controls, and communications infrastructure.
FAQ
What is the meaning of the 'C' suffix in SMAJ78CA-13-F?
The 'C' denotes bidirectional configuration: the device clamps symmetrically for positive and negative transients, with no cathode band marking. This differs from unidirectional versions (e.g., SMAJ78A-13-F) that require correct anode/cathode orientation relative to circuit polarity.
Can SMAJ78CA-13-F be used in place of SMAJ78A-13-F without redesign?
Yes, electrically - both share identical VRWM, VBR, VC, and IPP values - but physical layout must accommodate bidirectional symmetry: no polarity-sensitive placement is needed, and PCB footprint remains identical. No schematic change is required if the original design already used a bidirectional TVS or had no polarity constraint.
What is the maximum allowable surge repetition rate for reliable operation?
Per datasheet Note 6, the device is rated for ≤4 pulses per minute at 8.3ms half-sine waveform. Higher repetition rates cause thermal accumulation beyond PM(AV) = 1.0W, risking parametric shift or failure. For repetitive surges, derating curves in Figure 1 must be applied based on ambient and board thermal design.
Does SMAJ78CA-13-F meet AEC-Q200 requirements?
No - standard SMAJ78CA-13-F is not AEC-Q200 qualified. The automotive-grade variant is SMAJ78CAQ-13-F, which undergoes additional stress testing, is manufactured in IATF 16949-certified facilities, and supports PPAP documentation. Use SMAJ78CAQ-13-F for production automotive applications.
SMAJ78CA-13-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 2.2A
- Power - Peak Pulse:
- 400W
- 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:
- SMA
SMAJ78CA-13-F FAQ
1.How can I place an order for SMAJ78CA-13-F through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ78CA-13-F 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 SMAJ78CA-13-F reliable?
The price and inventory of SMAJ78CA-13-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ78CA-13-F is usually 5 days.
3.What payment methods are accepted for SMAJ78CA-13-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ78CA-13-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ78CA-13-F?
SMAJ78CA-13-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ78CA-13-F 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 SMAJ78CA-13-F?
For technical support, including SMAJ78CA-13-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ78CA-13-F requirements.
6.How does Aetrix verify that SMAJ78CA-13-F is sourced from the original manufacturer or authorized distributors?
All SMAJ78CA-13-F 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 SMAJ78CA-13-F meets industry standards.
7.What is the process for return or replacement of SMAJ78CA-13-F?
All SMAJ78CA-13-F units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ78CA-13-F, 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 SMAJ78CA-13-F part is unused and in its original packaging.
Return procedure for SMAJ78CA-13-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ78CA-13-F 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
