My Inquiry
My Account
onsemi BZX85C20_T50R
- Part No.:
- BZX85C20_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZX85C20_T50R.pdf
- Description:
- DIODE ZENER 20V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:4,292
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BZX85C20_T50R from onsemi is a 20 V ±5% tolerance, 1.0 W axial-leaded Zener diode in DO-41 glass package, rated for 24 mA zener test current, with 10 Ω dynamic impedance at IZ and 0.5 μA maximum leakage at 14 V reverse voltage. It provides precise voltage regulation in low-power power supply feedback, overvoltage protection, and reference circuits.
For engineers reviewing the BZX85C20_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, power derating above 50°C (6.67 mW/°C), thermal stability across −65°C to +200°C, and DO-41 mechanical compatibility with through-hole PCB layouts.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown when reverse-biased above its nominal 20 V zener voltage. Its 10 Ω zener impedance at 24 mA ensures stable regulation under moderate load variation, while the 0.5 μA leakage at 14 V supports low-quiescent-current designs.
The DO-41 glass package enables reliable thermal dissipation up to 1.0 W at 25°C ambient, with linear derating to zero at 175°C junction temperature. The cathode band marking and axial lead configuration conform to JEDEC DO-204AL standards for manual and automated assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18.8 V min / 21.2 V max at IZ = 24 mA - defines regulated output range for feedback or clamp circuits |
| Power Dissipation (PD) | 1.0 W @ TA = 25°C - sets maximum continuous power handling without heatsinking |
| Zener Impedance (ZZ) | 10 Ω @ IZ = 24 mA - determines output voltage deviation under load current changes |
| Leakage Current (IR) | 0.5 μA max @ VR = 14 V - ensures minimal standby current in high-impedance bias networks |
| Operating Temp Range | −65°C to +200°C - supports industrial and automotive under-hood applications |
| Thermal Derating | 6.67 mW/°C above 50°C - defines safe power reduction slope for elevated ambient conditions |
Pinout & Package
DO-41 glass axial package with cathode indicated by a single color band on the body; leads are unmarked anode/cathode terminals suitable for through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Forward conduction terminal | Connected to lower-potential node in reverse-bias regulation configuration |
| Cathode (banded end) | Zener breakdown terminal | Connected to higher-potential node; voltage referenced to this terminal during regulation |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Ensures predictable clamping level across production lots without post-assembly trimming |
| 1.0 W power rating | Supports direct regulation of small-signal rails (e.g., 5 V, 12 V, 24 V) without external pass devices |
| Low 0.5 μA leakage at 14 V | Minimizes error in high-resistance voltage divider references and battery-powered monitoring |
| DO-41 glass package | Provides hermetic sealing and proven reliability in humid or thermally cycling environments |
| JEDEC DO-204AL compliance | Guarantees mechanical interchangeability with legacy axial Zener diodes in existing tooling and fixtures |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Clamp Protection |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback converters via optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Zener reference element setting upper threshold for TL431 or optocoupler LED drive current. Use Value: Tight 20 V ±5% tolerance ensures consistent output regulation across line/load variations without calibration. |
Use Scenario: Protecting microcontroller I/O pins against transient surges exceeding 14 V. IC Role / Device Role / Timing Role: Shunt clamping device diverting excess energy to ground before damage occurs. Use Value: 0.5 μA leakage preserves signal integrity in high-impedance input circuits during normal operation. |
| Voltage Reference for ADC | Industrial Sensor Excitation |
Use Scenario: Providing stable 20 V reference for 12-bit analog-to-digital conversion in data acquisition modules. IC Role / Device Role / Timing Role: Precision DC voltage source for ratiometric scaling of sensor signals. Use Value: 10 Ω zener impedance limits reference voltage shift to <10 mV under 1 mA load variation. |
Use Scenario: Biasing resistive temperature detectors (RTDs) in 4–20 mA transmitter front-ends. IC Role / Device Role / Timing Role: Constant-voltage excitation source enabling linear resistance-to-current conversion. Use Value: −65°C to +200°C operating range maintains accuracy across wide ambient temperature extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4744A | 20 V nominal, ±5%, 1.0 W, DO-41, but 22 Ω ZZ @ 25 mA vs. BZX85C20_T50R's 10 Ω | Higher impedance reduces regulation precision under dynamic load; suitable where tighter tolerance is less critical | Select when legacy design uses 1N47xx footprint and 22 Ω impedance is acceptable |
| MMSZ5248B | 20 V nominal, ±5%, 500 mW, SOD-123 surface-mount, 30 Ω ZZ @ 20 mA | Lower power rating and SMT form factor limit use to space-constrained, low-power PCBs | Choose for compact consumer electronics where board area is constrained and 500 mW suffices |
Compared with 1N4744A and MMSZ5248B, BZX85C20_T50R delivers superior regulation stability (10 Ω ZZ) and full 1.0 W capability in a robust DO-41 glass package-making it optimal for industrial power supplies and high-reliability clamping where thermal margin and impedance matter.
Availability
BZX85C20_T50R is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and precision voltage reference designs requiring stable component supply and long-term manufacturability.
Supply support for BZX85C20_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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BZX85C series was designed for general-purpose voltage regulation and protection in cost-sensitive, high-volume applications-emphasizing reliability, tight tolerance, and broad temperature operation in standard axial packages.
FAQ
What is the exact zener voltage range for BZX85C20_T50R?
The BZX85C20_T50R has a guaranteed zener voltage range of 18.8 V to 21.2 V at IZ = 24 mA and TA = 25°C, per the onsemi datasheet revision 2 (October 2017). This ±5% tolerance is measured under thermal equilibrium at 30°C lead temperature with 3/8″ lead length, ensuring repeatable performance in production testing.
Does BZX85C20_T50R have a specified forward voltage?
Yes, BZX85C20_T50R specifies a maximum forward voltage (VF) of 1.2 V at IF = 200 mA, as stated in the "Electrical Characteristics" section of the official datasheet. This value applies only during forward conduction and is not relevant to its primary zener regulation function.
Can BZX85C20_T50R be used in surface-mount designs?
No-BZX85C20_T50R uses a DO-41 axial glass package with 0.406 mm diameter leads and 25.4 mm minimum lead spacing, designed exclusively for through-hole mounting. For surface-mount equivalents, consider the MMSZ5248B (SOD-123) or NZ9F20ST5G (SOD-923), which differ in power rating and impedance.
What is the maximum allowable junction temperature for BZX85C20_T50R?
The absolute maximum junction and storage temperature for BZX85C20_T50R is +200°C, with a minimum of −65°C. At ambient temperatures above 50°C, power must be linearly derated at 6.67 mW/°C, reaching zero dissipation at 175°C case temperature-consistent with its 1.0 W rating at 25°C.
How is the cathode identified on BZX85C20_T50R?
The cathode of BZX85C20_T50R is marked by a single color band on the glass body, per JEDEC DO-204AL standard. This band aligns with the cathode terminal, and the opposite (unbanded) end is the anode-critical for correct polarity in reverse-bias regulation or clamping configurations.
BZX85C20_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 20 V
- Tolerance:
- ±6%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 24 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 14 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
BZX85C20_T50R FAQ
1.How can I place an order for BZX85C20_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX85C20_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 BZX85C20_T50R reliable?
The price and inventory of BZX85C20_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX85C20_T50R is usually 5 days.
3.What payment methods are accepted for BZX85C20_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX85C20_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX85C20_T50R?
BZX85C20_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX85C20_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 BZX85C20_T50R?
For technical support, including BZX85C20_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX85C20_T50R requirements.
6.How does Aetrix verify that BZX85C20_T50R is sourced from the original manufacturer or authorized distributors?
All BZX85C20_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 BZX85C20_T50R meets industry standards.
7.What is the process for return or replacement of BZX85C20_T50R?
All BZX85C20_T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX85C20_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 BZX85C20_T50R part is unused and in its original packaging.
Return procedure for BZX85C20_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX85C20_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…
