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onsemi 1SMB5948BT3
- Part No.:
- 1SMB5948BT3
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB5948BT3.pdf
- Description:
- DIODE ZENER 91V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:6,764
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Product details
Overview
1SMB5948BT3 from onsemi is a 3 W surface-mount Zener diode with nominal Zener voltage of 91 V, ±5% tolerance, maximum Zener impedance of 4.1 Ω at 200 mA test current, and reverse leakage current ≤0.25 μA at 69.2 V. It operates from −65 °C to +150 °C and is used for overvoltage protection and precision voltage reference in DC power supplies.
For engineers reviewing the 1SMB5948BT3 datasheet, pinout, applications, or equivalent options, key selection criteria include its 91 V Zener voltage rating, 3 W steady-state power dissipation at TL = 75 °C, low dynamic impedance, AEC−Q101 qualification status (SZ variant), and SMB package compatibility with automated SMT assembly.
Technical Context
This device functions as a two-terminal voltage regulation element operating in reverse breakdown. Its Zener voltage is specified at IZT = 200 mA with thermal equilibrium at TL = 30 °C, and it exhibits a positive temperature coefficient above ~6 V, typical for higher-voltage Zeners.
The SMB package (Case 403A) provides a modified L-bend leadform optimized for top- or bottom-side PCB mounting, with UL 94 V−0 flammability rating, Pb-free availability (G suffix), and ESD robustness >16 kV per HBM - critical for automotive and industrial environments where transient immunity is required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 91 V nominal (min 86.45 V, max 95.55 V) - defines precise clamping threshold for overvoltage protection circuits |
| Power Dissipation (PD) | 3.0 W at TL = 75 °C - supports high-energy transient suppression without heatsinking when mounted on thermally adequate PCB |
| Zener Impedance (ZZT) | 4.1 Ω max at IZT = 200 mA - ensures stable regulation under load variations in feedback or reference applications |
| Reverse Leakage (IR) | ≤0.25 μA at VR = 69.2 V - enables low-power standby operation with minimal quiescent current loss |
| Thermal Resistance (RJA) | 226 °C/W - determines junction temperature rise under ambient conditions; requires layout-aware copper area for thermal management |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - suitable for handling in non-ESD-controlled production environments |
| Operating Temperature | −65 °C to +150 °C - validated for under-hood automotive, industrial control, and outdoor power electronics |
Pinout & Package
SMB package (Case 403A), surface-mount plastic case with cathode polarity band. Dimensions: 4.06–4.60 mm width (E), 3.30–3.95 mm length (D), 1.90–2.28 mm height (A), 0.76–1.60 mm lead length (L).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference node | Connected to lower-potential side of protected circuit; forms reference ground for clamp configuration |
| Cathode | Reverse breakdown terminal / Zener voltage output node | Connected to higher-potential rail; clamps voltage to 91 V during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| 3 W Power Rating | Enables robust surge energy absorption (e.g., 1000 W peak for 1 ms pulses) without derating in compact SMB footprint |
| ±5% Zener Tolerance | Guarantees tight voltage accuracy across production lots, reducing need for post-assembly calibration in reference designs |
| AEC−Q101 Qualified Variant | SZ1SMB5948BT3G meets automotive reliability standards - supports functional safety–related overvoltage monitoring in ADAS ECUs |
| Flat Handling Surface | Ensures consistent pick-and-place placement accuracy during high-speed SMT assembly, minimizing tombstoning risk |
| Pb-Free (G suffix) | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profiles without solderability compromise |
Applications
| Industrial Power Supply Protection | Automotive Battery Monitoring |
|---|---|
|
Use Scenario: Clamping transient spikes on 24 V/48 V DC bus lines in PLC power modules during relay switching or load dump. IC Role / Device Role / Timing Role: Two-terminal passive voltage clamp; no timing function - responds within nanoseconds to overvoltage events. Use Value: Prevents damage to downstream DC-DC controllers and microcontrollers by limiting bus voltage to ≤95.55 V during 100 ms surges up to 3 W average power. |
Use Scenario: Reference voltage source for analog-to-digital conversion of battery voltage in vehicle body control modules. IC Role / Device Role / Timing Role: Precision voltage reference node; stable 91 V output enables accurate scaling of 0–16 V battery range to ADC full-scale. Use Value: Delivers <0.25 μA leakage at 69.2 V, minimizing measurement error in high-impedance sensing networks while maintaining ±5% accuracy over −40 °C to +125 °C. |
| Telecom Line Card Surge Suppression | Renewable Energy Inverter DC Link Monitoring |
|
Use Scenario: Secondary overvoltage protection on PoE-powered Ethernet line cards subjected to lightning-induced surges. IC Role / Device Role / Timing Role: Standby-mode shunt regulator; activated only during fault conditions - zero static power draw in normal operation. Use Value: Withstands 16 kV HBM ESD and absorbs 1000 W pulse energy (per Figure 2), complementing primary TVS arrays without requiring additional board space. |
Use Scenario: DC link voltage monitoring in solar microinverters where 900 V DC bus must be scaled for isolation amplifier input. IC Role / Device Role / Timing Role: High-voltage Zener divider element; used with precision resistors to generate 91 V reference from 900 V bus. Use Value: 4.1 Ω Zener impedance ensures minimal loading error (<0.5%) on resistor divider network, preserving measurement linearity across temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5948BRLG | Same 91 V nominal Zener voltage, but DO-41 through-hole package; 1.5 W power rating; no AEC−Q101 qualification | Requires manual or wave soldering; unsuitable for high-density SMT layouts or automotive PPAP programs | Select when legacy through-hole assembly is mandated and thermal budget allows 1.5 W derating |
| SZ1SMB5948BT3G | Identical electrical specs and SMB package; differs only in AEC−Q101 qualification, PPAP capability, and SZ prefix for automotive traceability | Required for automotive OEM BOMs; supports ASIL-B functional safety documentation requirements | Select for automotive applications where qualified part status and change control are mandatory |
Compared with 1SMB5948BT3, 1N5948BRLG offers mechanical compatibility with legacy through-hole designs but sacrifices power handling and modern packaging; SZ1SMB5948BT3G delivers identical performance with certified automotive reliability - making it the preferred choice when supply chain compliance outweighs cost sensitivity.
Availability
1SMB5948BT3 is available at Aetrix Electronics and suitable for industrial power supply protection, automotive battery monitoring, telecom surge suppression, and renewable energy inverter DC link monitoring requiring stable component supply and long-term obsolescence management.
Supply support for 1SMB5948BT3 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, signal processing, and sensor technologies for automotive, industrial, cloud, and consumer markets.
The 1SMB59xxBT3 series is part of onsemi's high-reliability Zener regulator portfolio designed for ruggedized voltage reference and overvoltage protection in harsh-environment applications including automotive under-hood systems and industrial automation.
FAQ
What is the Zener voltage tolerance of the 1SMB5948BT3?
The 1SMB5948BT3 has a ±5% Zener voltage tolerance, meaning its nominal 91 V rating spans 86.45 V (minimum) to 95.55 V (maximum) at IZT = 200 mA and TL = 30 °C. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official datasheet and applies across the full operating temperature range.
Is the 1SMB5948BT3 suitable for automotive applications?
The standard 1SMB5948BT3 is not AEC−Q101 qualified; however, its automotive-grade variant SZ1SMB5948BT3G is fully qualified and PPAP-capable. For automotive use, engineers must specify the SZ prefix version - the 1SMB5948BT3 itself meets all electrical and mechanical specs but lacks the required reliability validation and traceability controls.
What is the maximum reverse leakage current for the 1SMB5948BT3?
The 1SMB5948BT3 specifies a maximum reverse leakage current (IR) of 0.25 μA at VR = 69.2 V (80% of nominal Zener voltage). This value is measured at TL = 30 °C and ensures minimal standby power loss in high-impedance reference circuits.
Can the 1SMB5948BT3 be used in place of the 1N5948B?
No - the 1SMB5948BT3 is an SMB surface-mount device, while the 1N5948B is a DO-41 through-hole diode. They share the same 91 V Zener voltage but differ in package, power rating (3 W vs. 1.5 W), thermal resistance, and mounting method. Direct substitution requires PCB redesign and thermal reassessment.
What is the Zener impedance of the 1SMB5948BT3 at its rated test current?
The 1SMB5948BT3 has a maximum Zener impedance (ZZT) of 4.1 Ω at IZT = 200 mA, as specified in the Electrical Characteristics table. This low dynamic impedance ensures tight voltage regulation under varying load conditions, especially critical in precision reference applications.
1SMB5948BT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 91 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 200 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 69.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB5948BT3 FAQ
1.How can I place an order for 1SMB5948BT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB5948BT3 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 1SMB5948BT3 reliable?
The price and inventory of 1SMB5948BT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB5948BT3 is usually 5 days.
3.What payment methods are accepted for 1SMB5948BT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB5948BT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB5948BT3?
1SMB5948BT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB5948BT3 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 1SMB5948BT3?
For technical support, including 1SMB5948BT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB5948BT3 requirements.
6.How does Aetrix verify that 1SMB5948BT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB5948BT3 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 1SMB5948BT3 meets industry standards.
7.What is the process for return or replacement of 1SMB5948BT3?
All 1SMB5948BT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB5948BT3, 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 1SMB5948BT3 part is unused and in its original packaging.
Return procedure for 1SMB5948BT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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