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onsemi SZ1SMA5940BT3G
- Part No.:
- SZ1SMA5940BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SZ1SMA5940BT3G.pdf
- Description:
- DIODE ZENER 43V 1.5W SMA
- Quantity:
- Payment:
- Shipping:
Inventory:596
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Product details
Overview
SZ1SMA5940BT3G from onsemi is a 1.5 W surface-mount Zener diode with nominal zener voltage of 43 V, maximum zener impedance of 8.7 Ω at 53 mA test current, and reverse leakage current ≤0.25 μA at 32.7 V. It operates across −65 °C to +150 °C and is AEC−Q101 qualified for automotive power regulation and voltage reference applications.
For engineers reviewing the SZ1SMA5940BT3G datasheet, pinout, applications, or equivalent options, key selection criteria include its ±5% voltage tolerance, low-profile SMA package, 16 kV HBM ESD rating, and thermal resistance of 250 °C/W (junction-to-ambient) under standard FR-4 mounting conditions.
Technical Context
This device functions as a precision voltage reference and overvoltage clamp in DC power rails and analog signal conditioning circuits. Its zener breakdown is specified at IZT = 53 mA with VZ = 40.85–45.15 V, and it maintains stable regulation down to IZK = 0.5 mA where ZZK ≤ 950 Ω.
The SZ1SMA5940BT3G series uses void-free transfer-molded plastic packaging (CASE 403D, SMA) with cathode indicated by a molded band. It supports top-slide or bottom-board mounting and complies with UL 94 V−0 flammability rating and Pb−Free requirements per J-STD-609.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 40.85–45.15 V @ IZT = 53 mA - defines regulated output range for feedback loops and reference stability |
| Power Dissipation (PD) | 0.5 W @ TA = 25°C - limits continuous operation without heatsinking on standard PCBs |
| Zener Impedance (ZZT) | 8.7 Ω max @ IZT - ensures minimal voltage deviation under load transients |
| Reverse Leakage (IR) | ≤0.25 μA @ VR = 32.7 V - guarantees low standby current in battery-powered systems |
| Thermal Resistance (RJA) | 250 °C/W - determines junction temperature rise under ambient conditions with minimum footprint |
| ESD Rating | Class 3 (>16 kV HBM) - enables robust handling and integration into unshielded automotive modules |
| Operating Temp Range | −65 °C to +150 °C - supports under-hood and industrial control environments |
Pinout & Package
Package: SMA (Case 403D), surface-mount, low-profile plastic package with flat handling surface and molded cathode band. Cathode polarity is marked by a visible band on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Band End) | Zener anode connection in reverse-bias configuration | Connected to higher-potential node; clamps voltage when reverse-biased beyond VZ |
| Anode (Opposite End) | Zener cathode connection in reverse-bias configuration | Connected to lower-potential node (e.g., ground or return path); completes bias circuit |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive power management systems requiring PPAP documentation and zero-defect reliability |
| ±5% voltage tolerance | Ensures predictable regulation without post-production trimming in cost-sensitive consumer and industrial designs |
| 16 kV HBM ESD rating | Eliminates need for external ESD protection in board-level assembly and field-deployed equipment |
| Low-profile SMA package | Enables high-density PCB layouts and compatibility with automated optical inspection (AOI) and reflow processes |
| Pb−Free construction | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-609 Category 3 moisture sensitivity level (MSL) |
Applications
| Automotive Engine Control Unit (ECU) Power Rail Clamp | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: Clamping transient spikes on 48 V supply lines feeding microcontroller power domains in engine control units. IC Role / Device Role / Timing Role: Zener voltage regulator acting as shunt overvoltage protector downstream of DC/DC converters. Use Value: Prevents latch-up or damage to 3.3 V logic ICs during load-dump events using its 43 V nominal breakdown and 1.5 W peak dissipation capability. | Use Scenario: Protecting 0–10 V analog input channels from wiring-induced surges in programmable logic controllers. IC Role / Device Role / Timing Role: Precision voltage reference and fault clamp in front-end signal conditioning circuitry. Use Value: Maintains measurement accuracy with ≤0.25 μA leakage at 32.7 V while absorbing >100 V transients via controlled avalanche behavior. |
| Medical Infusion Pump Voltage Reference | Telecom Power Supply Feedback Divider |
Use Scenario: Providing stable 43 V reference for isolated current-sense amplifier biasing in battery-operated infusion pumps. IC Role / Device Role / Timing Role: Low-drift voltage reference element in closed-loop motor control feedback paths. Use Value: Delivers <±5% tolerance and −65 °C to +150 °C operation required for Class II medical device certification and long-term calibration stability. | Use Scenario: Setting output voltage in secondary-side feedback networks of isolated AC/DC adapters for telecom base stations. IC Role / Device Role / Timing Role: Zener-based voltage divider node in optocoupler-coupled feedback loop. Use Value: Enables accurate 48 V output regulation with 8.7 Ω dynamic impedance minimizing error under varying load conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1SMA5940BT3G | No AEC−Q101 qualification; identical electrical specs and SMA package | Not suitable for automotive production; acceptable for industrial prototypes and commercial-grade power supplies | Select when automotive qualification is not required and cost optimization is prioritized |
| MMSZ5268ET1G | Lower power rating (500 mW), tighter tolerance (±5%), same 43 V nominal, SOD-123 package | Better suited for space-constrained portable electronics; limited surge energy absorption vs. 1.5 W rating | Choose for compact PCBs where thermal margin allows reduced power derating |
Compared with 1SMA5940BT3G and MMSZ5268ET1G, the SZ1SMA5940BT3G provides automotive-grade reliability and higher surge handling capacity, making it optimal for safety-critical 43 V reference and clamp roles where long-term stability and environmental ruggedness are mandatory.
Availability
SZ1SMA5940BT3G is available at Aetrix Electronics and suitable for automotive ECU power rail clamping, industrial PLC analog input protection, and medical infusion pump voltage reference applications requiring stable component supply and AEC−Q101 compliance.
Supply support for SZ1SMA5940BT3G 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 SZ1SMA59xxBT3G series was designed specifically for automotive-grade voltage regulation and transient suppression, combining AEC−Q101 qualification with robust thermal performance in the industry-standard SMA package.
FAQ
What is the nominal zener voltage of the SZ1SMA5940BT3G?
The SZ1SMA5940BT3G has a nominal zener voltage of 43 V, with guaranteed minimum and maximum values of 40.85 V and 45.15 V respectively at a test current of 53 mA. This ±5% tolerance is confirmed in the onsemi datasheet's Electrical Characteristics table and applies across the full operating temperature range.
Is the SZ1SMA5940BT3G suitable for automotive applications?
Yes, the SZ1SMA5940BT3G is AEC−Q101 qualified and PPAP capable, explicitly designated for automotive use with the "SZ" prefix. Its construction, testing, and traceability meet automotive quality system requirements, and it is rated for operation from −65 °C to +150 °C-covering under-hood and transmission control module environments.
What is the maximum power dissipation of the SZ1SMA5940BT3G at room temperature?
The SZ1SMA5940BT3G has a maximum DC power dissipation of 0.5 W at ambient temperature (TA) = 25°C on an FR-4 board with onsemi's recommended footprint. Derating begins at 4.0 mW/°C above 25°C, reaching 1.5 W only at lead temperature (TL) = 75°C with zero lead length-a condition requiring direct thermal coupling to a heatsink or copper plane.
Does the SZ1SMA5940BT3G have a Pb−Free package?
Yes, the SZ1SMA5940BT3G is Pb−Free and complies with RoHS Directive 2011/65/EU. The "G" suffix in the part number and the marking diagram confirm Pb−Free construction, and the device uses void-free transfer-molded plastic with solderable leads compatible with standard reflow profiles up to 260°C for 10 seconds.
What is the reverse leakage current specification for the SZ1SMA5940BT3G?
The reverse leakage current for the SZ1SMA5940BT3G is specified as ≤0.25 μA at a reverse voltage (VR) of 32.7 V, measured at TA = 25°C. This low leakage ensures minimal quiescent current draw in battery-backed systems and preserves accuracy in high-impedance reference circuits where leakage could introduce offset errors.
SZ1SMA5940BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SZ1SMA59xxBT3G
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 43 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 53 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 32.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
SZ1SMA5940BT3G FAQ
1.How can I place an order for SZ1SMA5940BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMA5940BT3G 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 SZ1SMA5940BT3G reliable?
The price and inventory of SZ1SMA5940BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMA5940BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMA5940BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMA5940BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMA5940BT3G?
SZ1SMA5940BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMA5940BT3G 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 SZ1SMA5940BT3G?
For technical support, including SZ1SMA5940BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMA5940BT3G requirements.
6.How does Aetrix verify that SZ1SMA5940BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMA5940BT3G 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 SZ1SMA5940BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMA5940BT3G?
All SZ1SMA5940BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMA5940BT3G, 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 SZ1SMA5940BT3G part is unused and in its original packaging.
Return procedure for SZ1SMA5940BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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