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onsemi SZ1SMA5937BT3G
- Part No.:
- SZ1SMA5937BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SZ1SMA5937BT3G.pdf
- Description:
- DIODE ZENER 33V 1.5W SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,747
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Product details
Overview
SZ1SMA5937BT3G from onsemi is a 1.5 W surface-mount Zener diode with nominal zener voltage 33 V, maximum zener impedance 11.4 Ω at 33 mA test current, and reverse leakage current ≤0.25 μA at 25.1 V, used for precision voltage regulation in automotive power supply rails and industrial sensor biasing circuits.
For engineers reviewing the SZ1SMA5937BT3G datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance (±5%), thermal resistance (250 °C/W), AEC−Q101 qualification, and SMA package compatibility with automated SMT placement.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to maintain stable output voltage across varying load currents. Its 33 V nominal zener voltage falls within the 12–68 V range where temperature coefficient is positive and rises with increasing voltage, reaching +22 mV/°C per typical curve data.
The SMA package enables top-slide or bottom-board mounting with flat handling surface and Pb-free construction. It supports 1.5 W dissipation at 75 °C lead temperature, derating linearly to 0.5 W at 25 °C ambient, with junction-to-ambient thermal resistance of 250 °C/W on FR-4 board.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 31.35 V min / 33 V nom / 34.65 V max at IZT = 33 mA - defines regulated output voltage window under standard test conditions |
| Zener Impedance (ZZT) | 11.4 Ω max at IZT = 33 mA - determines output voltage stability under dynamic load changes |
| Max DC Zener Current (IZM) | 45 mA - sets absolute upper limit for continuous reverse conduction without thermal damage |
| Reverse Leakage (IR) | ≤0.25 μA at VR = 25.1 V - ensures minimal standby power loss in high-impedance bias networks |
| Power Dissipation (PD) | 1.5 W @ TL = 75 °C - requires thermal management via copper pad or heatsinking for sustained operation |
| ESD Rating | Class 3 (>16 kV) HBM - enables robust handling in automotive assembly environments without special ESD controls |
| AEC−Q101 Qualified | Yes - validates reliability for automotive electronic control units and under-hood applications |
Pinout & Package
SMA package (Case 403D), surface-mount, low-profile plastic case with molded cathode band. Cathode terminal marked by polarity notch/band; anode is unmarked end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Reverse-biased voltage reference node | Connected to regulated output rail; must be held at higher potential than anode during regulation |
| Anode (unmarked end) | Reference ground or return path | Typically tied to system ground or lower-voltage rail; completes current path during breakdown conduction |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity, and mechanical shock testing |
| ±5% zener voltage tolerance | Enables predictable regulation without post-manufacture trimming in cost-sensitive designs |
| 16 kV HBM ESD rating | Eliminates need for external ESD protection in board-level handling and final assembly |
| Flat handling surface | Ensures consistent pick-and-place accuracy during high-speed SMT assembly |
| Pb-free construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements |
Applications
| Automotive Engine Control Unit (ECU) Reference | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Providing stable 33 V reference for analog front-end circuitry in diesel engine ECU modules exposed to wide ambient temperature swings. IC Role / Device Role / Timing Role: Zener voltage regulator establishing precise bias point for op-amp comparators and ADC reference dividers. Use Value: Maintains ±1.65 V regulation window over −40 °C to +125 °C operating range, supporting AEC−Q100 Grade 0 compliance. | Use Scenario: Biasing high-precision RTD or strain gauge bridges in factory automation pressure transmitters. IC Role / Device Role / Timing Role: Two-terminal shunt regulator delivering low-noise, low-drift excitation voltage to bridge elements. Use Value: 11.4 Ω dynamic impedance minimizes output voltage variation under bridge current fluctuations up to ±2 mA. |
| Telecom Power Supply Overvoltage Clamp | Medical Diagnostic Equipment Voltage Monitor |
Use Scenario: Clamping transient overvoltage events on 24 V telecom DC distribution bus during lightning-induced surges. IC Role / Device Role / Timing Role: Fast-response shunt protector absorbing energy spikes while holding downstream voltage below 35 V. Use Value: 45 mA maximum zener current allows safe clamping of 1.01 W transient pulses without thermal runaway. | Use Scenario: Monitoring battery pack voltage in portable ultrasound devices to trigger low-power warning at 33 V threshold. IC Role / Device Role / Timing Role: Precision voltage threshold detector using reverse leakage current as sensing signal. Use Value: ≤0.25 μA leakage at 25.1 V enables microamp-level monitoring current, extending battery life beyond 12 hours. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C33LT1G | 33 V nominal, 300 mW power rating, SOT-23 package, 70 Ω ZZT at 5 mA | Lower power and higher impedance limit use to low-current biasing only | Select when board space is constrained and regulation load <5 mA |
| SZ1SMA5936BT3G | 30 V nominal, same 1.5 W rating, 12.5 Ω ZZT at 26 mA | Lower voltage suits 24 V system monitoring; identical thermal and packaging behavior | Select when 30 V regulation aligns with system rail tolerance budget |
Compared with BZX84-C33LT1G and SZ1SMA5936BT3G, SZ1SMA5937BT3G delivers tighter voltage regulation (±5% vs ±6% for BZX84), higher power headroom (1.5 W vs 0.3 W), and lower dynamic impedance (11.4 Ω vs 70 Ω), making it suitable for automotive and industrial applications requiring robust, high-stability voltage references.
Availability
SZ1SMA5937BT3G is available at Aetrix Electronics and suitable for automotive ECU design, industrial sensor conditioning, and telecom power clamping requiring stable component supply and AEC−Q101 compliance.
Supply support for SZ1SMA5937BT3G 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 power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The 1SMA59xxBT3G/SZ1SMA59xxBT3G series was designed specifically for high-reliability voltage regulation in automotive electronics and harsh-environment industrial systems, emphasizing AEC−Q101 qualification, low-profile SMT compatibility, and tight zener voltage tolerances.
FAQ
What is the nominal zener voltage of SZ1SMA5937BT3G and its tolerance?
The SZ1SMA5937BT3G has a nominal zener voltage of 33 V with a tolerance of ±5%, meaning the actual measured voltage at 33 mA test current falls between 31.35 V and 34.65 V. This tolerance is guaranteed at thermal equilibrium and applies across the full operating temperature range of −65 °C to +150 °C. The SZ1SMA5937BT3G datasheet specifies this range in the Electrical Characteristics table on page 2.
Is SZ1SMA5937BT3G qualified for automotive applications?
Yes, SZ1SMA5937BT3G is AEC−Q101 qualified and PPAP capable, confirming its suitability for automotive electronic control units, body electronics, and powertrain subsystems. The "SZ" prefix explicitly denotes automotive-grade manufacturing controls and site-specific change management. This qualification covers temperature cycling, mechanical shock, and humidity testing per AEC standards, and is documented in the onsemi datasheet revision history.
What is the maximum power dissipation of SZ1SMA5937BT3G and how does it derate with temperature?
SZ1SMA5937BT3G has a maximum DC power dissipation of 1.5 W at 75 °C lead temperature, derating at 20 mW/°C above that point. At 25 °C ambient temperature on an FR-4 board, the rated dissipation drops to 0.5 W with derating of 4.0 mW/°C above 25 °C. These values are defined in the Maximum Ratings table and assume specified PCB footprint per onsemi's recommended layout guidelines.
What package type does SZ1SMA5937BT3G use and what are its mounting features?
SZ1SMA5937BT3G uses the SMA package (Case 403D), a low-profile surface-mount plastic package with flat handling surface for accurate pick-and-place placement. It supports both top-slide and bottom-circuit board mounting configurations and features a molded cathode band for polarity identification. The package is void-free, corrosion-resistant, and UL 94 V-0 rated, with Pb-free construction compliant with RoHS.
What is the zener impedance of SZ1SMA5937BT3G and why does it matter?
The maximum zener impedance (ZZT) of SZ1SMA5937BT3G is 11.4 Ω at IZT = 33 mA, indicating how tightly the device maintains its regulated voltage under changing load current. Lower impedance means smaller output voltage deviation during transient load steps - critical for precision analog circuits like sensor biasing or reference dividers. This value is measured at thermal equilibrium and is confirmed in the Electrical Characteristics table on page 2 of the SZ1SMA5937BT3G datasheet.
SZ1SMA5937BT3G 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):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 33 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 25.1 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
SZ1SMA5937BT3G FAQ
1.How can I place an order for SZ1SMA5937BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMA5937BT3G 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 SZ1SMA5937BT3G reliable?
The price and inventory of SZ1SMA5937BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMA5937BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMA5937BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMA5937BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMA5937BT3G?
SZ1SMA5937BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMA5937BT3G 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 SZ1SMA5937BT3G?
For technical support, including SZ1SMA5937BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMA5937BT3G requirements.
6.How does Aetrix verify that SZ1SMA5937BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMA5937BT3G 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 SZ1SMA5937BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMA5937BT3G?
All SZ1SMA5937BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMA5937BT3G, 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 SZ1SMA5937BT3G part is unused and in its original packaging.
Return procedure for SZ1SMA5937BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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