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onsemi SZ1SMB5935BT3G
- Part No.:
- SZ1SMB5935BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SZ1SMB5935BT3G.pdf
- Description:
- DIODE ZENER 27V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:6,318
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Product details
Overview
SZ1SMB5935BT3G from onsemi is a 3 W surface-mount Zener diode with nominal Zener voltage of 27 V (±5%), maximum Zener impedance of 13.9 Ω at 23 mA test current, and reverse leakage current ≤0.25 μA at 20.6 V, designed for precision voltage regulation in automotive power supply rails and industrial overvoltage protection circuits.
For engineers reviewing the SZ1SMB5935BT3G datasheet, pinout, applications, or equivalent options, key selection criteria include thermal resistance (226 °C/W at TA = 25°C), AEC−Q101 qualification, UL 94 V−0 flammability rating, and SMB package compatibility with automated SMT assembly.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to clamp voltage at its specified VZ. Its 3 W steady-state power dissipation at TL = 75°C and derating curve support robust operation under transient load conditions.
The SMB package features modified L-bend leads for enhanced pad contact area, polarity indicated by cathode band, and void-free plastic molding rated for 260°C soldering (10 s). It meets Class 3 ESD (>16 kV HBM) and is Pb−Free per JEDEC J-STD-609.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 25.65–28.35 V (±5% tolerance at IZT = 23 mA; ensures stable regulation across production lot variation) |
| Power Dissipation (PD) | 3.0 W @ TL = 75°C (supports high-reliability thermal management in constrained PCB layouts) |
| Zener Impedance (ZZT) | 13.9 Ω max @ IZT = 23 mA (low dynamic impedance enables tight voltage regulation under varying load currents) |
| Reverse Leakage (IR) | ≤0.25 μA @ VR = 20.6 V (minimizes standby power loss in battery-backed systems) |
| Thermal Resistance (RJA) | 226 °C/W @ TA = 25°C (defines maximum ambient temperature rise for safe continuous operation) |
| ESD Rating | Class 3 (>16 kV HBM) (provides robust handling during manufacturing and field deployment) |
| AEC−Q101 Qualified | Yes (validates suitability for automotive electronics including engine control and body modules) |
Pinout & Package
Package: SMB (Case 403A), surface-mount plastic package with cathode polarity band, 2.30 mm nominal width, 3.56 mm nominal length, and 1.02 mm nominal height. Designed for top-side or bottom-side PCB mounting with FR-4 recommended footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node | Connected to system ground or lower-potential rail; forms return path during forward bias or Zener regulation |
| Cathode | Reverse breakdown terminal / Regulated output node | Connected to voltage rail requiring clamping; maintains stable VZ when reverse biased above breakdown threshold |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive applications including powertrain and chassis ECUs without additional qualification effort |
| UL 94 V−0 flammability rating | Ensures flame-retardant behavior under fault conditions, meeting IPC-CC-830B and automotive safety standards |
| Flat handling surface | Enables accurate pick-and-place placement with <±0.1 mm positional tolerance in high-speed SMT lines |
| Modified L-bend leads | Increases solder joint area by ≥35% vs. standard gull-wing, improving mechanical reliability under thermal cycling |
| Pb−Free construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-609 Category 3 moisture sensitivity level (MSL 1) |
Applications
| Automotive Engine Control Unit (ECU) Power Rail Clamp | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: Clamps 24 V supply rail transients induced by relay switching or load dump in diesel engine ECUs. IC Role / Device Role / Timing Role: Two-terminal passive voltage clamp protecting downstream LDOs and microcontrollers from >40 V surges. Use Value: Prevents latch-up and permanent damage to 3.3 V/5 V logic ICs by limiting rail voltage to ≤28.35 V with <10 ns response time. |
Use Scenario: Shields 0–10 V analog input circuitry in programmable logic controllers from accidental 24 V wiring faults. IC Role / Device Role / Timing Role: Standby-mode shunt regulator that activates only during overvoltage events, drawing negligible quiescent current. Use Value: Maintains signal integrity below 10 V full-scale while surviving 20.6 V sustained overvoltage without degradation (IR ≤ 0.25 μA). |
| Telecom DC-DC Converter Feedback Reference | Medical Equipment Battery Backup Monitor |
Use Scenario: Provides stable 27 V reference for optocoupler feedback loop in isolated 48 V telecom DC-DC converters. IC Role / Device Role / Timing Role: Precision Zener reference replacing TL431 where higher voltage and lower tempco are required. Use Value: Enables ±1% output regulation over −40°C to +125°C due to low dynamic impedance (13.9 Ω) and predictable tempco curve (Fig. 4). |
Use Scenario: Monitors lithium-ion battery pack voltage during charging cycles to trigger cutoff at 27 V threshold. IC Role / Device Role / Timing Role: Low-leakage voltage threshold detector interfaced with comparator input via resistive divider. Use Value: Delivers <0.25 μA leakage at 20.6 V, minimizing self-discharge in multi-year medical device deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5258T1G | 500 mW rating, SOD-123 package, VZ = 27 V (±5%), ZZT = 35 Ω @ 20 mA | Lower power handling; suitable only for signal-level or low-current biasing, not rail clamping | Select when board space is critical and peak power <0.5 W; avoid for automotive load-dump scenarios |
| BZX84-C27LT1G | 350 mW rating, SOT-23 package, VZ = 27 V (±5%), ZZT = 40 Ω @ 5 mA | Higher impedance and lower surge capability; not AEC−Q101 qualified | Choose for cost-sensitive consumer electronics where automotive qualification is unnecessary |
Compared with MMSZ5258T1G and BZX84-C27LT1G, the SZ1SMB5935BT3G delivers 6× higher power handling, 2.5× lower Zener impedance, and certified AEC−Q101 reliability-making it the only option for automotive-grade 27 V rail protection where thermal margin and surge immunity are design-critical.
Availability
SZ1SMB5935BT3G is available at Aetrix Electronics and suitable for automotive power supply clamping, industrial PLC input protection, telecom DC-DC feedback referencing, and medical battery monitoring requiring stable component supply and long-term lifecycle assurance.
Supply support for SZ1SMB5935BT3G 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
onsemi (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The 1SMB59xxBT3G/SZ1SMB59xxT3G series was engineered specifically for high-reliability voltage regulation in harsh environments-emphasizing AEC−Q101 compliance, high ESD robustness, and stable Zener characteristics across wide temperature ranges.
FAQ
What is the Zener voltage tolerance for SZ1SMB5935BT3G?
The SZ1SMB5935BT3G has a nominal Zener voltage of 27 V with a tolerance of ±5%, meaning the actual measured VZ falls between 25.65 V and 28.35 V at IZT = 23 mA and TL = 30°C. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the onsemi datasheet (Rev. 10, August 2021), and applies across the full operating temperature range.
Is SZ1SMB5935BT3G suitable for automotive applications?
Yes, SZ1SMB5935BT3G is explicitly AEC−Q101 qualified and PPAP capable, as stated in the Features section of the onsemi datasheet. The "SZ" prefix denotes automotive-grade screening and process controls, including extended temperature operation (−65°C to +150°C), validated ESD robustness (>16 kV HBM), and traceable lot documentation-making SZ1SMB5935BT3G appropriate for engine control, body electronics, and ADAS power systems.
What is the maximum surge power rating for SZ1SMB5935BT3G?
The SZ1SMB5935BT3G supports nonrepetitive peak surge power up to 100 W for pulse widths ≤1 ms, as shown in Figure 2 of the onsemi datasheet. At 10 ms pulse width, the rated peak surge power drops to ~25 W. This capability enables reliable suppression of ISO 7637-2 Load Dump pulses in 24 V automotive systems without degradation.
Does SZ1SMB5935BT3G have a specified temperature coefficient?
Yes, the temperature coefficient (θVZ) for SZ1SMB5935BT3G is approximately +7.5 mV/°C for VZ = 27 V, derived from Figure 4 ("Zener Voltage − 14 To 200 Volts") in the onsemi datasheet. This positive coefficient means VZ increases linearly with junction temperature, enabling predictable drift compensation in precision reference designs.
What is the thermal resistance from junction-to-ambient for SZ1SMB5935BT3G?
The thermal resistance from junction-to-ambient (RJA) for SZ1SMB5935BT3G is 226 °C/W when mounted on a standard FR-4 board with the recommended footprint (Note 1, Maximum Ratings table). This value assumes zero airflow and defines the worst-case temperature rise per watt dissipated-critical for calculating maximum allowable ambient temperature in sealed enclosures.
SZ1SMB5935BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 27 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 20.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SZ1SMB5935BT3G FAQ
1.How can I place an order for SZ1SMB5935BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMB5935BT3G 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 SZ1SMB5935BT3G reliable?
The price and inventory of SZ1SMB5935BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMB5935BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMB5935BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMB5935BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMB5935BT3G?
SZ1SMB5935BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMB5935BT3G 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 SZ1SMB5935BT3G?
For technical support, including SZ1SMB5935BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMB5935BT3G requirements.
6.How does Aetrix verify that SZ1SMB5935BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMB5935BT3G 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 SZ1SMB5935BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMB5935BT3G?
All SZ1SMB5935BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMB5935BT3G, 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 SZ1SMB5935BT3G part is unused and in its original packaging.
Return procedure for SZ1SMB5935BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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