My Inquiry
My Account
onsemi BZX55C39_T50R
- Part No.:
- BZX55C39_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
BZX55C39_T50R.pdf
- Description:
- DIODE ZENER 39V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:7,660
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BZX55C39_T50R from ON Semiconductor (formerly Fairchild) is a 39 V, ±5% tolerance Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 90 Ω dynamic impedance at 2.5 mA test current and 0.1 μA reverse leakage at 32 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog circuits.
For engineers reviewing the BZX55C39_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior, cathode-band polarity marking, DO-35 mechanical compatibility, and reverse leakage performance at elevated temperatures.
Technical Context
The BZX55C39_T50R operates as a silicon planar Zener diode relying on controlled avalanche breakdown. Its 39 V nominal zener voltage is specified at 2.5 mA test current, with 90 Ω dynamic impedance indicating moderate regulation stiffness under small-signal conditions.
Thermal design requires adherence to 4.0 mW/°C derating above 75°C lead temperature, and operation must remain within -65°C to +200°C junction/storage range. Reverse leakage remains ≤0.1 μA up to 32 V, supporting stable biasing in high-impedance nodes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.0 V min / 41.0 V max at 2.5 mA - defines usable regulation window for 39 V nominal reference |
| Tolerance | ±5% - enables predictable clamping within 2 V band at room temperature |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - sets maximum continuous DC or pulsed power in standard lead-length mounting |
| Dynamic Impedance (ZZ) | 90 Ω @ IZ = 2.5 mA - determines output voltage variation under load current changes |
| Reverse Leakage (IR) | ≤0.1 μA @ VR = 32 V - ensures minimal error current in high-Z reference dividers |
| Operating Temperature | -65°C to +200°C - supports deployment in automotive under-hood or industrial ambient environments |
Pinout & Package
DO-35 glass axial package with cathode indicated by color band; two-terminal device with no internal connections beyond anode and cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node during forward bias; carries full forward current up to 100 mA |
| Cathode | Zener breakdown terminal | Marked with color band; connected to higher-potential node during regulation; sinks zener current into ground or return path |
Key Features
| Feature | Design Value |
|---|---|
| Stable 39 V reference | Guaranteed 37–41 V range at 2.5 mA enables repeatable threshold setting in comparator inputs |
| Low leakage | 0.1 μA max at 32 V minimizes loading error in high-resistance voltage dividers |
| DO-35 compatibility | Standard 2.0 mm diameter glass body with 5 mm length fits legacy through-hole footprints and automated insertion tooling |
| Thermal robustness | Rated for -65°C to +200°C operation supports reliability-critical applications without derating penalties |
Applications
| Overvoltage Protection | Fixed Voltage Reference |
|---|---|
Use Scenario: Clamping transient spikes on 3.3 V or 5 V logic supply rails in microcontroller-based systems. IC Role / Device Role: Shunt regulator that conducts excess current when rail exceeds safe threshold. Use Value: Limits voltage excursions to ≤41 V, protecting downstream CMOS inputs rated for 6 V absolute maximum. | Use Scenario: Providing stable 39 V reference for ADC input scaling in industrial sensor signal conditioning. IC Role / Device Role: Precision voltage source establishing known full-scale point for analog-to-digital conversion. Use Value: Enables ±5% reference accuracy without trimming, reducing calibration steps in production test. |
| Power Supply Feedback | LED Current Regulation |
Use Scenario: Setting feedback threshold in isolated flyback converter secondary-side regulation loop. IC Role / Device Role: Zener element defining error amplifier trip point for optocoupler-driven control. Use Value: Maintains consistent output voltage despite line/load variations due to tight VZ tolerance and low ZZ. | Use Scenario: Biasing constant-current LED driver ICs requiring precise reference voltage for current mirror matching. IC Role / Device Role: Stable voltage node enabling accurate current-setting resistor calculation. Use Value: Delivers <0.1 μA leakage, preventing reference drift that would cause >1% LED current error in high-gain drivers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4739A | Same 39 V nominal, ±5% tolerance, but rated 1 W and uses DO-41 package | Higher power handling supports 1 W continuous dissipation; larger DO-41 footprint requires PCB redesign | Select when >500 mW steady-state power or improved thermal margin is required |
| BZX85C39 | 39 V, ±5%, 1.3 W rating in DO-41, higher IZM (32 mA vs. 28 mA) | Superior surge capability and lower ZZ (60 Ω); not drop-in due to different package and thermal profile | Prefer for high-reliability power supply references where long-term stability under load is critical |
Compared with 1N4739A and BZX85C39, the BZX55C39_T50R offers tighter integration into space-constrained DO-35 layouts while maintaining adequate regulation accuracy and leakage performance for low-power analog functions-ideal where board area and thermal mass are constrained.
Availability
BZX55C39_T50R is available at Aetrix Electronics and suitable for overvoltage protection, fixed voltage reference, power supply feedback, and LED current regulation requiring stable component supply across industrial control, instrumentation, and embedded power management designs.
Supply support for BZX55C39_T50R 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
ON Semiconductor is a global semiconductor supplier delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud computing, medical, and IoT applications.
The BZX55 series was designed as a general-purpose, cost-optimized Zener diode family targeting precision voltage regulation and clamping in low-to-medium power analog circuits.
FAQ
What is the zener voltage tolerance of BZX55C39_T50R?
The BZX55C39_T50R has a ±5% zener voltage tolerance, meaning its actual breakdown voltage falls between 37.0 V and 41.0 V when measured at the specified 2.5 mA test current and 25°C ambient. This tolerance is guaranteed per the original Fairchild datasheet Rev. D1 and applies to all units marked BZX55C39_T50R.
What package type does BZX55C39_T50R use?
BZX55C39_T50R uses the DO-35 glass axial package, identifiable by its 2.0 mm diameter cylindrical glass body and color-coded cathode band. The package supports standard through-hole mounting and conforms to JEDEC DO-35 mechanical dimensions, including 5 mm body length and 0.45 mm lead diameter.
What is the maximum power dissipation for BZX55C39_T50R?
The BZX55C39_T50R is rated for 500 mW maximum power dissipation at a lead temperature (TL) of ≤75°C with 3/8″ lead length. Power must be linearly derated by 4.0 mW/°C above 75°C, limiting usable dissipation to 400 mW at TL = 100°C.
How much reverse leakage current does BZX55C39_T50R exhibit?
BZX55C39_T50R exhibits ≤0.1 μA reverse leakage current at VR = 32 V and TA = 25°C. This low leakage ensures minimal loading error in high-impedance reference networks and supports stable operation in battery-powered or ultra-low-power analog stages.
Is BZX55C39_T50R suitable for automotive applications?
Yes, BZX55C39_T50R is suitable for automotive applications due to its -65°C to +200°C operating and storage temperature range, which exceeds AEC-Q200 Grade 3 requirements. Its DO-35 glass construction and stable zener characteristics support under-hood sensor interfaces and power rail clamping where extended thermal cycling is expected.
BZX55C39_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 90 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 28 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.3 V @ 100 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
BZX55C39_T50R FAQ
1.How can I place an order for BZX55C39_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX55C39_T50R 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 BZX55C39_T50R reliable?
The price and inventory of BZX55C39_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX55C39_T50R is usually 5 days.
3.What payment methods are accepted for BZX55C39_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX55C39_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX55C39_T50R?
BZX55C39_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX55C39_T50R 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 BZX55C39_T50R?
For technical support, including BZX55C39_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX55C39_T50R requirements.
6.How does Aetrix verify that BZX55C39_T50R is sourced from the original manufacturer or authorized distributors?
All BZX55C39_T50R 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 BZX55C39_T50R meets industry standards.
7.What is the process for return or replacement of BZX55C39_T50R?
All BZX55C39_T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX55C39_T50R, 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 BZX55C39_T50R part is unused and in its original packaging.
Return procedure for BZX55C39_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX55C39_T50R Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
