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Microchip Technology 1N5343B/TR8
- Part No.:
- 1N5343B/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5343B/TR8.pdf
- Description:
- DIODE ZENER 7.5V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:7,965
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Product details
Overview
1N5343B/TR8 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 7.5 V ±5%, 175 mA test current, 1.5 Ω dynamic impedance at IZT, 10 μA reverse leakage at 5.4 V, and 630 mA maximum Zener current when adequately heat-sunk. It serves as a precision voltage reference in power supply feedback loops and overvoltage protection circuits.
For engineers reviewing the 1N5343B/TR8 datasheet, 1N5343B/TR8 pinout, 1N5343B/TR8 application, or 1N5343B/TR8 equivalent, key selection criteria include its ±5% tolerance, low 1.5 Ω Zener impedance at 175 mA, 10 μA IR at VR = 5.4 V, thermal resistance of 25 °C/W (junction-to-lead), and compatibility with standard T-18 axial package mounting on FR4 PCBs.
Technical Context
The 1N5343B/TR8 operates as a two-terminal voltage regulator diode, conducting in reverse breakdown to maintain stable 7.5 V across its terminals within specified current and temperature limits. Its design supports steady-state operation up to 5 W at TL < 25 °C with 3/8″ lead length, and derates linearly above that temperature.
It exhibits minimal voltage variation (ΔVZ = 0.15 V) between 10% and 50% of IZM, confirming tight regulation performance. The device is moisture-sensitive Level 1 per J-STD-020B and requires no dry pack, with RoHS-compliant matte-tin plating and UL94V-0 epoxy encapsulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.5 V ±5% - precise regulation point for feedback or clamp circuits |
| Test Current (IZT) | 175 mA - operating point where VZ and ZZ are specified |
| Dynamic Impedance (ZZ) | 1.5 Ω at IZT - low AC resistance ensures stable output under load transients |
| Reverse Leakage (IR) | 10 μA at VR = 5.4 V - low off-state current minimizes standby power loss |
| Max Zener Current (IZM) | 630 mA - peak DC current achievable with proper heat sinking |
| Power Dissipation | 5.0 W at TL < 25 °C - defines thermal design boundary for lead-mounted operation |
| Voltage Regulation (ΔVZ) | 0.15 V - difference between VZ measured at 10% and 50% of IZM |
Pinout & Package
Package: T-18 axial-leaded plastic case per JEDEC DO-41 outline; cathode indicated by band; leads are tin-lead or RoHS-compliant matte-tin plated; weight 0.7 g; moisture sensitivity Level 1 (no dry pack required).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-voltage side in reverse-bias regulation | Connected to circuit ground or lower potential node during Zener operation |
| Cathode | Reverse breakdown terminal / high-voltage side in regulation | Banded end; connected to unregulated input or voltage rail being clamped |
Key Features
| Feature | Design Value |
|---|---|
| ±5% voltage tolerance (B suffix) | Enables tighter regulation than ±10% or ±20% variants without requiring custom screening |
| Low 1.5 Ω dynamic impedance at 175 mA | Reduces output voltage deviation under varying load currents in feedback networks |
| 630 mA maximum Zener current with heat sinking | Supports higher-power shunt regulation than standard 1 W Zeners in compact axial form |
| 25 °C/W junction-to-lead thermal resistance | Allows direct thermal path to PCB copper or chassis via 3/8″ lead length for reliable 5 W operation |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Clamp Protection |
|---|---|
Use Scenario: Used in optocoupler-coupled feedback loop of isolated DC-DC converters to regulate output voltage. IC Role / Device Role / Timing Role: Precision voltage reference setting error amplifier threshold. Use Value: 7.5 V ±5% tolerance and 1.5 Ω ZZ ensure stable regulation across line/load variations and temperature. | Use Scenario: Placed across sensitive IC supply rails to limit transient overvoltage events. IC Role / Device Role / Timing Role: Shunt clamping element diverting excess energy to ground during surges. Use Value: 630 mA IZM and 0.15 V ΔVZ provide predictable, repeatable clamping with minimal overshoot. |
| Industrial Sensor Excitation Reference | Programmable Voltage Threshold Detector |
Use Scenario: Supplies stable excitation voltage to resistive bridge sensors in process control transmitters. IC Role / Device Role / Timing Role: Low-drift DC reference source for analog front-end biasing. Use Value: 10 μA IR at 5.4 V and 25 °C/W thermal resistance support low-power, thermally stable operation. | Use Scenario: Configured with comparator to trigger shutdown when input exceeds 7.5 V threshold. IC Role / Device Role / Timing Role: Fixed reference input to comparator's inverting or non-inverting input. Use Value: Tight ±5% tolerance and low ΔVZ ensure accurate, repeatable trip-point definition. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5343B (bulk) | Identical electrical specs; differs only in packaging - bulk vs. tape-and-reel (TR8) | No functional difference; TR8 enables automated SMT placement, bulk supports manual/hand-soldered assembly | Select 1N5343B/TR8 for pick-and-place production; choose bulk for prototyping or low-volume hand assembly |
| MMBZ5233BS-7-F (Diodes Inc.) | Surface-mount SOD-123 package; 7.5 V ±5%; 100 mA IZT; 20 Ω ZZ - higher impedance, lower power (0.35 W) | Not suitable for 5 W dissipation; limited to low-current references or signal-level clamping | Use MMBZ5233BS-7-F only where board space is constrained and power < 0.35 W; retain 1N5343B/TR8 for full 5 W capability |
Compared with 1N5343B (bulk) and MMBZ5233BS-7-F, the 1N5343B/TR8 delivers identical regulation performance in tape-and-reel format for automated manufacturing, while maintaining full 5 W power handling - a capability not matched by surface-mount alternatives.
Availability
1N5343B/TR8 is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, industrial sensor excitation, and programmable threshold detection requiring stable component supply and JEDEC-standard axial Zener performance.
Supply support for 1N5343B/TR8 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N53xxB series was designed as a ruggedized, high-power axial Zener family delivering stable voltage regulation from 3.3 V to 200 V with MIL-qualified screening options and industry-standard T-18 packaging.
FAQ
What is the Zener voltage tolerance of the 1N5343B/TR8?
The 1N5343B/TR8 has a nominal Zener voltage of 7.5 V with a tolerance of ±5%, as indicated by the "B" suffix per Microsemi documentation. This tolerance applies across the full operating temperature range of –65 °C to +150 °C and is verified at 25 °C lead temperature using 175 mA test current.
What is the maximum power dissipation of the 1N5343B/TR8 under standard conditions?
The 1N5343B/TR8 is rated for 5.0 W steady-state power dissipation at a lead temperature (TL) below 25 °C with 3/8″ (10 mm) lead length from the body. Derating begins linearly above 25 °C, reaching zero at 150 °C, per the published power derating curve in the Microsemi datasheet.
Does the 1N5343B/TR8 require dry packing for moisture sensitivity?
No, the 1N5343B/TR8 has a moisture sensitivity level (MSL) of Level 1 per IPC/JEDEC J-STD-020B, meaning it is not moisture-sensitive and does not require dry pack or baking prior to soldering. Its void-free epoxy encapsulation provides inherent moisture resistance.
What is the reverse leakage current specification for the 1N5343B/TR8?
The 1N5343B/TR8 specifies a maximum reverse leakage current (IR) of 10 μA at a reverse test voltage (VR) of 5.4 V, measured at 25 °C. This value reflects the diode's ability to block current below its Zener knee, critical for low-power reference and clamp applications.
How is polarity marked on the 1N5343B/TR8 package?
The 1N5343B/TR8 uses a cathode band marking on the body to indicate polarity: the banded end is the cathode and must be connected to the higher-potential node during Zener operation (i.e., reverse-biased configuration). The opposite (unbanded) end is the anode.
1N5343B/TR8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- T-18, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 7.5 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 1.5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 5.4 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 1 A
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- T-18
1N5343B/TR8 FAQ
1.How can I place an order for 1N5343B/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5343B/TR8 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 1N5343B/TR8 reliable?
The price and inventory of 1N5343B/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5343B/TR8 is usually 5 days.
3.What payment methods are accepted for 1N5343B/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5343B/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5343B/TR8?
1N5343B/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5343B/TR8 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 1N5343B/TR8?
For technical support, including 1N5343B/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5343B/TR8 requirements.
6.How does Aetrix verify that 1N5343B/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N5343B/TR8 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 1N5343B/TR8 meets industry standards.
7.What is the process for return or replacement of 1N5343B/TR8?
All 1N5343B/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5343B/TR8, 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 1N5343B/TR8 part is unused and in its original packaging.
Return procedure for 1N5343B/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5343B/TR8 Tags
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