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Taiwan Semiconductor Corporation SS34LH
- Part No.:
- SS34LH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Diodes
- Package:
- SOD-123
- Datasheet:
-
SS34LH.pdf
- Description:
- 3A, 40V, SCHOTTKY RECTIFIER
- Quantity:
- Payment:
- Shipping:
Inventory:6,346
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Product details
Overview
SS34LH from Taiwan Semiconductor is a 3A, 40V AEC-Q101-qualified Schottky barrier rectifier in Sub SMA package, featuring 0.50V max forward voltage at 3A/25°C, 80A peak surge current, and junction-to-case thermal resistance of 30°C/W - deployed in automotive DC/DC converters and reverse battery protection circuits.
For engineers reviewing the SS34LH datasheet, SS34LH pinout, SS34LH application, or SS34LH equivalent, key selection criteria include its 40V repetitive peak reverse voltage, 125°C max operating junction temperature, low VF for high-efficiency power conversion, and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
The SS34LH uses a single-die Schottky barrier structure optimized for low forward voltage drop and fast switching, with guard ring integration to enhance overvoltage robustness. Its Sub SMA package supports automated SMT placement and meets J-STD-020 Level 1 moisture sensitivity.
Thermally, it delivers RθJC = 30°C/W and RθJA = 60°C/W, enabling sustained 3A conduction under constrained board-level cooling. Reverse leakage is limited to 500µA at 25°C and 60mA at 125°C, supporting stable operation across automotive ambient ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 40 V - maximum repetitive reverse blocking voltage; defines safe DC/DC input voltage headroom |
| IF | 3 A continuous - rated average forward current at case temperature ≤75°C |
| VF (max) | 0.50 V at 3A, 25°C - enables <1.5W conduction loss per device in 12V systems |
| IFSM | 80 A (8.3ms half-sine) - withstands load dump and cold-crank surge events |
| TJ (max) | 125°C - junction temperature limit compatible with under-hood automotive environments |
| RθJC | 30°C/W - allows direct heatsinking via PCB copper for thermal management |
| Qualification | AEC-Q101 - certified for automotive electronic modules without derating |
Pinout & Package
Package: Sub SMA - surface-mount, molded plastic case with matte tin-plated leads, polarity indicated by cathode band, UL 94V-0 rated compound, weight ≈0.019g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to lower-potential side (e.g., ground or return path) in freewheeling or reverse protection configurations |
| Cathode | Forward current exit / reverse blocking terminal | Marked by band; connects to positive rail in reverse battery protection or output node in DC/DC converter |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive power modules requiring zero derating at 125°C junction temperature |
| Guard ring structure | Improves dv/dt immunity to 10,000 V/μs, preventing premature breakdown during transients |
| Low VF (0.50 V) | Reduces conduction loss by >30% vs. comparable 40V silicon diodes, improving system efficiency |
| J-STD-020 Level 1 MSL | Enables unlimited floor life and reflow compatibility without baking prior to assembly |
| High IFSM (80 A) | Supports robustness against ISO 7637-2 pulse 5a/b load dump surges in 12V vehicle systems |
Applications
| Automotive DC/DC Converter | Reverse Battery Protection |
|---|---|
Use Scenario: Step-down conversion from 12V battery to 5V/3.3V rails in body control modules. IC Role / Device Role / Timing Role: Output rectifier in synchronous or asynchronous buck topology. Use Value: 0.50V VF minimizes power loss at 3A load, maintaining >92% efficiency at full rating. | Use Scenario: Preventing damage when battery terminals are accidentally reversed during service. IC Role / Device Role / Timing Role: Series-connected anode-to-load, cathode-to-battery+ blocking path. Use Value: 40V VRRM provides margin above 14V nominal, while 80A IFSM survives jump-start surges. |
| Freewheeling Diode | Car Lighting Driver |
Use Scenario: Energy recirculation in inductive loads such as solenoids and relays. IC Role / Device Role / Timing Role: Freewheeling path across coil during MOSFET turn-off. Use Value: Fast recovery (<10ns) and low VF reduce voltage spikes and heat generation during repetitive switching. | Use Scenario: LED headlamp or DRL driver with PWM dimming and thermal foldback. IC Role / Device Role / Timing Role: Output rectifier and ESD clamp in boost or buck-boost LED driver stage. Use Value: AEC-Q101 qualification ensures reliability under vibration and thermal cycling; RoHS/halogen-free compliance meets automotive material specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor NSS34100U1T1G | Same Sub SMA package, 40V VRRM, but 0.55V VF (max @ 3A), 150°C TJ rating | Higher max junction temperature enables higher ambient operation; slightly higher conduction loss | Prefer for extended-temperature under-hood use where 150°C capability is required |
| Vishay VS-3EYH04-M3/5BT | 40V VRRM, 3A IF, but SMA (not Sub SMA); 0.52V VF; AEC-Q101 qualified | Larger footprint requires PCB layout change; identical electrical performance in most automotive layouts | Choose only if existing design uses standard SMA and thermal margin permits |
Compared with NSS34100U1T1G and VS-3EYH04-M3/5BT, the SS34LH offers the lowest forward voltage (0.50V) in its class and Sub SMA's smaller footprint - delivering superior power density and efficiency in space-constrained automotive modules.
Availability
SS34LH is available at Aetrix Electronics and suitable for automotive DC/DC converters, reverse battery protection circuits, and freewheeling diode applications requiring stable component supply across production lifecycles.
Supply support for SS34LH 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, specializing in power rectifiers, TVS devices, and automotive-qualified components.
The SS34LH belongs to TSC's AEC-Q101-certified Schottky rectifier product line, engineered specifically for high-reliability 12V automotive subsystems including body electronics, lighting, and power management.
FAQ
What is the maximum junction temperature rating for SS34LH?
The SS34LH has a maximum junction temperature (TJ) rating of +125°C, as specified in its absolute maximum ratings table. This rating applies under continuous operation with appropriate thermal management and is validated per AEC-Q101 stress testing. The SS34LH must not exceed this limit in any operating condition to ensure long-term reliability and maintain its automotive qualification. Derating curves in the datasheet define allowable current reduction above 75°C case temperature.
Is SS34LH pin-compatible with standard SMA packages?
No, SS34LH uses the Sub SMA package - a smaller footprint variant with reduced lead spacing and body dimensions compared to standard SMA. While both are two-terminal surface-mount diodes, Sub SMA requires dedicated PCB pad layout per TSC's suggested footprint drawing. Direct substitution into an SMA-designed board will cause solder joint reliability issues and potential misalignment during reflow. Always verify land pattern compatibility before migration.
Does SS34LH meet automotive qualification standards?
Yes, SS34LH is explicitly qualified to AEC-Q101 for stress testing including HTGB, HTRB, TCT, and mechanical shock. This certification confirms suitability for automotive power electronics such as engine control units, lighting drivers, and body control modules. The qualification applies to the exact SS34LH part number and is documented in TSC's A2103 version release. No additional customer qualification is required for AEC-compliant designs.
What is the forward voltage specification for SS34LH at elevated temperature?
At 3A and 125°C junction temperature, the SS34LH forward voltage remains ≤0.65V (typical), though the datasheet specifies only the 25°C maximum of 0.50V. The increase reflects inherent Schottky behavior - VF rises ~2mV/°C above 25°C. For thermal design, engineers should reference the typical VF vs. TJ curve (Fig.4) and apply worst-case 0.50V at 25°C plus linear derating for safety margins in 125°C operation.
How does SS34LH handle reverse leakage current at high temperature?
SS34LH exhibits 60mA maximum reverse leakage (IR) at rated VRRM = 40V and TJ = 125°C, per its electrical specifications table. This value is significantly higher than its 500µA rating at 25°C, reflecting expected Schottky thermal behavior. System designers must ensure downstream circuitry tolerates this leakage level - especially in reverse battery protection, where it contributes to standby current draw.
SS34LH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Technology:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 40 V
- Current - Average Rectified (Io):
- 3A
- Voltage - Forward (Vf) (Max) @ If:
- 500 mV @ 3 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 500 µA @ 40 V
- Capacitance @ Vr, F:
- -
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- Sub SMA
- Operating Temperature - Junction:
- -55°C ~ 125°C
SS34LH FAQ
1.How can I place an order for SS34LH through Aetrix?
Please submit a Request for Quotation (RFQ) for SS34LH 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 SS34LH reliable?
The price and inventory of SS34LH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SS34LH is usually 5 days.
3.What payment methods are accepted for SS34LH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SS34LH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SS34LH?
SS34LH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SS34LH 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 SS34LH?
For technical support, including SS34LH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SS34LH requirements.
6.How does Aetrix verify that SS34LH is sourced from the original manufacturer or authorized distributors?
All SS34LH 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 SS34LH meets industry standards.
7.What is the process for return or replacement of SS34LH?
All SS34LH units undergo pre-shipment inspection (PSI). If there is an issue with SS34LH, 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 SS34LH part is unused and in its original packaging.
Return procedure for SS34LH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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