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Taiwan Semiconductor Corporation SMAJ20CAH
- Part No.:
- SMAJ20CAH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ20CAH.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,778
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Product details
Overview
SMAJ20CAH from Taiwan Semiconductor is a bidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for automotive-grade surge protection with 20V working stand-off voltage, 22.2–24.5V breakdown range at 1mA, and 32.4V clamping voltage at 12.3A peak pulse current. It protects DC/DC converters and SMPS inputs against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMAJ20CAH datasheet, SMAJ20CAH pinout, SMAJ20CAH application, or SMAJ20CAH equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, 150°C junction temperature rating, moisture sensitivity level 1 compliance, and DO-214AC mechanical compatibility with automated SMT placement.
Technical Context
SMAJ20CAH is a glass-passivated, single-die, bidirectional TVS diode optimized for fast transient suppression in automotive and industrial power rails. Its sub-1ps response time ensures clamping before sensitive downstream circuitry is exposed to overvoltage events.
The device meets ISO 7637-2 immunity requirements for vehicle electrical systems and delivers 400W peak pulse power (10/1000μs waveform) up to 78V VWM, derating to 300W above that threshold. It operates across –55°C to +150°C with <1μA reverse leakage at rated VWM.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before significant leakage begins |
| VBR min/max | 22.2 V / 24.5 V @ 1 mA - Verified breakdown threshold ensuring reliable turn-on during transients |
| VC @ IPPM | 32.4 V @ 12.3 A - Clamped voltage seen by protected circuit under full 400W surge condition |
| PPPM | 400 W (10/1000μs) - Peak surge energy absorption capacity compatible with ISO 7637-2 test profiles |
| TJ max | +150 °C - Enables use in under-hood automotive environments without thermal derating penalties |
| IR @ VWM | <1 μA - Minimal standby power loss and negligible impact on high-impedance sensing nodes |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with 0.060 g mass and J-STD-002 solderability |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band, UL 94V-0 rated, JESD201 Class 2 whisker resistant, MSL Level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Transient return path for bidirectional clamping | Completes low-impedance surge shunt path in both polarities; connects to GND or low-side rail |
| Cathode (banded end) | Transient return path for bidirectional clamping | Completes low-impedance surge shunt path in both polarities; connects to protected line or high-side rail |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including HTOL, TC, UHAST, and ESD |
| Glass passivated junction | Enhances long-term reliability and stability of breakdown voltage under thermal cycling and humidity exposure |
| Fast response time <1 ps | Clamps transients before propagation into downstream ICs, enabling protection of high-speed digital interfaces |
| ISO 7637-2 compliance | Guarantees immunity to standardized automotive load dump and inductive switching pulses (Pulse 1/2a/2b/3a/3b) |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive for environmentally compliant manufacturing and end-of-life handling |
Applications
| Automotive Infotainment Power Rail | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 12V supply input to head unit MCU and display driver ICs against battery load dump and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional TVS clamping element placed directly at connector entry point before bulk capacitance. Use Value: Limits transient voltage to ≤32.4V, preventing latch-up or gate oxide damage in 3.3V/5V logic powered from buck-converted 12V rail. | Use Scenario: Safeguarding 24V digital input channels of programmable logic controllers against field-wiring induced surges and relay coil flyback. IC Role / Device Role / Timing Role: Primary front-end surge absorber mounted adjacent to terminal block, upstream of optocoupler isolation stage. Use Value: Absorbs 400W pulses without degradation, maintaining signal integrity and eliminating false triggering caused by >100V transients. |
| On-board DC/DC Converter Input | LED Driver Module Protection |
Use Scenario: Securing input stage of isolated 48V-to-12V DC/DC converter used in commercial vehicle lighting control modules. IC Role / Device Role / Timing Role: Fast-clamping TVS placed between input filter capacitor and primary-side MOSFET gate driver supply. Use Value: Prevents overvoltage-induced shoot-through in half-bridge drivers by clamping spikes within 1ps, preserving PWM timing fidelity. | Use Scenario: Shielding constant-current LED driver ICs from voltage reversals and ESD events during assembly and field service. IC Role / Device Role / Timing Role: Bidirectional transient suppressor connected across driver output terminals and chassis ground. Use Value: Withstands repeated ±15kV contact ESD per IEC 61000-4-2 while maintaining <1μA leakage at 20V, avoiding LED dimming drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ20CA | Same DO-214AC package, identical VWM/VBR/VC specs, but not AEC-Q101 qualified | Acceptable for industrial/commercial use; unsuitable for automotive OEM or Tier-1 production | Select when AEC-Q101 is not required and cost optimization is prioritized |
| Vishay SMAJ20CA-E3/5AT | Identical electrical parameters and AEC-Q101 qualification; differs only in tape-and-reel packaging (5000 pcs vs. 7500 pcs) | No functional difference; compatible in all design contexts requiring automotive-grade TVS | Select when preferred distributor stock or logistics alignment favors Vishay's packaging configuration |
Compared with SMAJ20CAH, Littelfuse SMAJ20CA lacks AEC-Q101 validation-critical for automotive deployment-while Vishay SMAJ20CA-E3/5AT matches all electrical and qualification specs but ships in smaller reels, affecting high-volume procurement planning.
Availability
SMAJ20CAH is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLCs, and on-board DC/DC converters requiring stable component supply with guaranteed AEC-Q101 compliance and traceable sourcing.
Supply support for SMAJ20CAH 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and consumer markets since 1979.
The SMAJ series is part of TSC's AEC-Q101-qualified TVS portfolio, engineered specifically for robust transient immunity in harsh automotive and industrial power environments where reliability under thermal and electrical stress is non-negotiable.
FAQ
What does the "CAH" suffix indicate in SMAJ20CAH?
The "CAH" suffix in SMAJ20CAH denotes a bidirectional configuration (C), AEC-Q101 qualification (A), and halogen-free construction (H). This distinguishes it from unidirectional "CH" variants and non-automotive "H" versions. SMAJ20CAH is explicitly rated for two-way transient suppression and certified to automotive reliability standards, making it suitable for safety-critical vehicle subsystems where polarity reversal must be tolerated.
Is SMAJ20CAH compatible with lead-free reflow soldering processes?
Yes, SMAJ20CAH supports lead-free reflow soldering per J-STD-020. Its matte tin-plated leads are fully solderable using standard Pb-free profiles, and the DO-214AC package is rated for peak temperatures up to 260°C. The device also complies with JESD201 Class 2 for whisker resistance, ensuring long-term interconnect reliability in thermally cycled automotive applications.
How does SMAJ20CAH perform under repeated surge stress?
SMAJ20CAH is rated for non-repetitive surges per Fig.5 (10/1000μs waveform); its 400W rating applies to single-event conditions. For repetitive transients, derating per Fig.2 is required-e.g., at 85°C ambient, peak power drops to ~280W. The device maintains parameter stability after 1000+ surge cycles at 50% of rated IPPM, validated per AEC-Q101 stress testing protocols.
Can SMAJ20CAH replace SMAJ20A in an existing design?
SMAJ20CAH can replace SMAJ20A only if bidirectional clamping and AEC-Q101 qualification are confirmed as required. SMAJ20A is unidirectional and not AEC-Q101 qualified; substituting SMAJ20CAH introduces symmetrical protection and automotive validation but requires verifying layout polarity independence and thermal margin due to identical package and power dissipation.
What is the maximum allowable mounting density for SMAJ20CAH on a PCB?
SMAJ20CAH has no defined minimum spacing requirement beyond standard DO-214AC thermal and clearance guidelines. Its 0.060g mass and UL 94V-0 molding compound allow dense placement, but thermal coupling must be managed: maintain ≥1.5 mm clearance to adjacent heat sources and use ≥2 oz copper pour beneath the pad for optimal heat spreading, especially in automotive under-hood applications exceeding 105°C ambient.
SMAJ20CAH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 12.3A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ20CAH FAQ
1.How can I place an order for SMAJ20CAH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ20CAH 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 SMAJ20CAH reliable?
The price and inventory of SMAJ20CAH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ20CAH is usually 5 days.
3.What payment methods are accepted for SMAJ20CAH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ20CAH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ20CAH?
SMAJ20CAH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ20CAH 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 SMAJ20CAH?
For technical support, including SMAJ20CAH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ20CAH requirements.
6.How does Aetrix verify that SMAJ20CAH is sourced from the original manufacturer or authorized distributors?
All SMAJ20CAH 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 SMAJ20CAH meets industry standards.
7.What is the process for return or replacement of SMAJ20CAH?
All SMAJ20CAH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ20CAH, 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 SMAJ20CAH part is unused and in its original packaging.
Return procedure for SMAJ20CAH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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