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onsemi 1SMA5942BT3G
- Part No.:
- 1SMA5942BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA5942BT3G.pdf
- Description:
- DIODE ZENER 51V 1.5W SMA
- Quantity:
- Payment:
- Shipping:
Inventory:15,987
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Product details
Overview
1SMA5942BT3G from onsemi is a 1.5 W surface-mount Zener diode with nominal zener voltage of 51 V, maximum zener impedance of 7.3 Ω at 70 mA test current, and reverse leakage current ≤0.25 μA at 38.8 V. It operates across −65 °C to +150 °C and is qualified to AEC−Q101 for automotive applications.
For engineers reviewing the 1SMA5942BT3G datasheet, pinout, applications, or equivalent options, this device serves as a precision voltage reference and overvoltage clamp in power supply regulation, ESD protection circuits, and voltage stabilization stages where tight ±5% tolerance and low dynamic impedance are required.
Technical Context
This Zener regulator uses silicon planar construction with void-free transfer-molded SMA package, enabling stable breakdown behavior under DC and transient conditions. Its thermal resistance junction-to-lead is 50 °C/W, supporting reliable 1.5 W dissipation at TL = 75 °C with 20 mW/°C derating above that temperature.
The device exhibits a positive temperature coefficient of ~12 mV/°C near 51 V (per Figure 6), and its zener voltage is specified at thermal equilibrium with IZT = 70 mA. It delivers <0.5 μA leakage at VR = 38.8 V and maintains ZZK ≤ 1100 Ω at IZK = 0.25 mA - critical for low-current regulation stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 48.45 V min / 51 V nom / 53.55 V max - ensures ±5% regulation window at IZT = 70 mA for stable reference generation |
| Power Dissipation (PD) | 1.5 W @ TL = 75 °C - supports robust thermal handling on copper pads without forced cooling |
| Zener Impedance (ZZT) | 7.3 Ω max @ IZT = 70 mA - enables low output ripple and fast transient response in feedback loops |
| Reverse Leakage (IR) | ≤0.25 μA @ VR = 38.8 V - minimizes standby current loss in battery-backed or low-power systems |
| ESD Rating | Class 3 (>16 kV HBM) - provides intrinsic ESD resilience without external protection in board-level interfaces |
| Operating Temp Range | −65 °C to +150 °C - validated for under-hood automotive, industrial control, and high-reliability power modules |
Pinout & Package
SMA package (Case 403D, Style 1), low-profile surface-mount plastic case with molded cathode band; polarity marked by cathode band on body; RoHS-compliant Pb-free construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Band End) | Zener breakdown anode connection | Connected to higher-potential rail; reverse-biased operation requires cathode at ≥VZ relative to anode |
| Anode (Non-Band End) | Zener breakdown cathode connection | Reference node or ground return path; defines clamping threshold when cathode is biased above this terminal |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Guarantees predictable regulation window without post-manufacture trimming in production designs |
| AEC−Q101 qualification | Validated reliability for automotive power management, including engine control units and ADAS power rails |
| UL 94 V−0 flammability rating | Meets safety standards for enclosed industrial equipment and consumer power adapters |
| Flat handling surface | Enables accurate pick-and-place placement during automated SMT assembly with minimal tombstoning risk |
| Top-slide or bottom-mount package design | Supports dual-side PCB assembly and compact layout in space-constrained power modules |
Applications
| Automotive Power Rail Clamp | Industrial SMPS Feedback Reference |
|---|---|
|
Use Scenario: Clamping transients on 48 V battery-supplied ECUs during load dump events. IC Role / Device Role / Timing Role: Zener voltage clamp protecting downstream regulators and microcontrollers from >60 V surges. Use Value: With 51 V nominal breakdown and 53.55 V max, it activates before damage thresholds of 55 V-rated ICs while maintaining low leakage (<0.25 μA) during normal operation. |
Use Scenario: Providing stable reference voltage for optocoupler-based feedback in isolated 24 V industrial switch-mode supplies. IC Role / Device Role / Timing Role: Precision shunt reference setting error amplifier trip point in secondary-side regulation loop. Use Value: 7.3 Ω dynamic impedance ensures <10 mV output variation across 50–100 mA load steps, improving output voltage accuracy to ±1.5%. |
| ESD Protection for Sensor Interfaces | Battery Voltage Monitor Threshold |
|
Use Scenario: Protecting analog inputs of automotive pressure sensors exposed to ISO 10605 pulses. IC Role / Device Role / Timing Role: Low-capacitance shunt clamp diverting ESD energy away from sensitive ADC front-ends. Use Value: Class 3 HBM rating (>16 kV) and fast turn-on enable clamping within nanoseconds, limiting voltage overshoot to <55 V during 8/20 μs transients. |
Use Scenario: Detecting undervoltage condition in LiFePO4 battery packs (nominal 48 V) before deep discharge. IC Role / Device Role / Timing Role: Zener-triggered comparator input defining 48.5 V alarm threshold. Use Value: Tight ±5% tolerance ensures consistent trip point across temperature (−40 °C to +125 °C), eliminating calibration drift in field-deployed units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5255B-TP | 50 V nominal, ±5%, 500 mW power rating, SOD-123 package, ZZT = 17 Ω @ 20 mA | Lower power and higher impedance limit use to signal-level references or low-current biasing | Select when board space is constrained and dissipation remains below 0.5 W; not suitable for 1.5 W clamping loads |
| SZ1SMA5942BT3G | Identical electrical specs and AEC−Q101 qualification; differs only in SZ prefix denoting automotive-specific traceability and PPAP support | Required for Tier 1 automotive BOMs mandating full PPAP documentation and lot traceability | Choose for OEM automotive programs requiring certified change control and manufacturing site tracking |
Compared with MMSZ5255B-TP, the 1SMA5942BT3G delivers 3× higher power handling and lower dynamic impedance for robust power rail clamping; compared with SZ1SMA5942BT3G, it shares identical performance but omits automotive-specific documentation - making it ideal for industrial and commercial applications where PPAP is not mandated.
Availability
1SMA5942BT3G is available at Aetrix Electronics and suitable for automotive power clamping, industrial SMPS feedback references, and battery voltage monitoring requiring stable component supply and long-term lifecycle continuity.
Supply support for 1SMA5942BT3G 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The 1SMA59xxBT3G series was developed to replace legacy MELF Zeners with enhanced manufacturability, AEC−Q101 compliance, and improved thermal performance in surface-mount power regulation.
FAQ
What is the zener voltage tolerance of the 1SMA5942BT3G?
The 1SMA5942BT3G has a guaranteed ±5% zener voltage tolerance, with minimum, nominal, and maximum values of 48.45 V, 51 V, and 53.55 V respectively, measured at IZT = 70 mA under thermal equilibrium conditions per the onsemi datasheet.
Can the 1SMA5942BT3G be used in automotive applications?
Yes, the 1SMA5942BT3G is AEC−Q101 qualified and PPAP capable, making it suitable for automotive power rail clamping, ECU protection, and sensor interface conditioning where extended temperature range (−65 °C to +150 °C) and reliability validation are required.
What is the maximum power dissipation for the 1SMA5942BT3G at ambient temperature?
The 1SMA5942BT3G dissipates up to 0.5 W at TA = 25 °C, derating linearly at 4.0 mW/°C above that temperature. At TL = 75 °C (lead temperature), it supports full 1.5 W dissipation with 20 mW/°C derating beyond that point.
How does the 1SMA5942BT3G compare to the SZ1SMA5942BT3G variant?
The 1SMA5942BT3G and SZ1SMA5942BT3G share identical electrical specifications, packaging, and AEC−Q101 qualification. The SZ prefix indicates additional automotive-specific traceability, change control, and PPAP documentation - required for Tier 1 OEM programs but not for general industrial use.
What is the reverse leakage current specification for the 1SMA5942BT3G?
The 1SMA5942BT3G specifies reverse leakage current ≤0.25 μA at VR = 38.8 V (80% of nominal VZ). This low leakage ensures minimal standby power loss in battery-powered systems and high-impedance reference circuits.
1SMA5942BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 1SMA59xxBT3G
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 51 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 70 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 38.8 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA5942BT3G FAQ
1.How can I place an order for 1SMA5942BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA5942BT3G 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 1SMA5942BT3G reliable?
The price and inventory of 1SMA5942BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA5942BT3G is usually 5 days.
3.What payment methods are accepted for 1SMA5942BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA5942BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA5942BT3G?
1SMA5942BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA5942BT3G 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 1SMA5942BT3G?
For technical support, including 1SMA5942BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA5942BT3G requirements.
6.How does Aetrix verify that 1SMA5942BT3G is sourced from the original manufacturer or authorized distributors?
All 1SMA5942BT3G 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 1SMA5942BT3G meets industry standards.
7.What is the process for return or replacement of 1SMA5942BT3G?
All 1SMA5942BT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA5942BT3G, 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 1SMA5942BT3G part is unused and in its original packaging.
Return procedure for 1SMA5942BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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