My Inquiry
My Account
onsemi BZX84C20
- Part No.:
- BZX84C20
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84C20.pdf
- Description:
- DIODE ZENER 20V 350MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:5,619
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BZX84C20 from ON Semiconductor (formerly Fairchild) is a 20 V ±5% tolerance surface-mount Zener diode in SOT-23 package, rated for 250 mW power dissipation at 25°C ambient, with typical zener impedance of 20 Ω at 20 mA and reverse leakage current ≤0.05 µA at 14 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the BZX84C20 datasheet, pinout, applications, or equivalent options, key selection considerations include its 20 V nominal zener voltage, 5% tolerance, 250 mW power rating, 20 Ω dynamic impedance at 20 mA, and SOT-23 package compatibility with automated PCB assembly.
Technical Context
The BZX84C20 operates as a silicon planar epitaxial Zener diode optimized for stable voltage reference and clamping functions in DC bias networks and signal conditioning paths. Its design targets low-current regulation (1–20 mA range) with predictable temperature coefficient (+14.4 mV/°C at 5 mA) and minimal capacitance (85 pF at 0 V).
It features a cathode-anode polarity configuration with no internal series resistance or integrated transient suppression-functionality relies entirely on intrinsic Zener breakdown characteristics. Thermal performance is defined by junction-to-ambient resistance of 465°C/W on FR-4 PCB (76.2 mm × 114.3 mm), limiting continuous operation to ≤150°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 20 V (min 18.8 V, max 21.2 V at 5 mA; defines regulated output level) |
| Zener Impedance | 20 Ω (at 20 mA; determines voltage deviation under load variation) |
| Power Dissipation | 250 mW (at TA = 25°C; sets maximum steady-state thermal load on PCB) |
| Tolerance | ±5% (C-grade marking; ensures voltage accuracy across production lot) |
| Reverse Leakage Current | ≤0.05 µA (at VR = 14 V; guarantees minimal quiescent current in standby mode) |
| Capacitance | 85 pF (at VR = 0 V, f = 1 MHz; impacts high-frequency noise coupling in filtering apps) |
| Tempco (dVZ/dT) | +14.4 mV/°C (at IZ = 5 mA; enables predictable drift compensation in temp-stable refs) |
Pinout & Package
Package: SOT-23 (3-pin, small-outline transistor), 1.3 mm × 2.9 mm footprint, cathode-marked terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path / Zener cathode reference node | Connected to lower-potential side of regulated circuit; forms reference ground for clamp function |
| Cathode | Zener breakdown terminal / voltage reference output | Connected to regulated rail; delivers stable 20 V when reverse-biased above breakdown threshold |
| NC | No connection | SOT-23 third pin is unconnected die pad; no electrical function or thermal tie required |
Key Features
| Feature | Design Value |
|---|---|
| Stable 20 V reference | Guaranteed 18.8–21.2 V range at 5 mA enables repeatable biasing in sensor interfaces |
| Low dynamic impedance | 20 Ω at 20 mA minimizes output voltage shift under varying load currents |
| Low leakage current | ≤0.05 µA at 14 V supports ultra-low-power battery-backed monitoring circuits |
| Surface-mount SOT-23 | Enables high-density placement and reflow-compatible manufacturing for compact PCBs |
| Predictable tempco | +14.4 mV/°C allows first-order temperature compensation in precision references |
Applications
| Industrial Sensor Biasing | USB Port Overvoltage Clamp |
|---|---|
Use Scenario: Providing stable 20 V bias to bridge-based pressure sensors in factory automation modules. IC Role / Device Role / Timing Role: Zener diode acting as shunt voltage reference for excitation circuitry. Use Value: Maintains sensor linearity within ±0.5% full-scale error across -40°C to +85°C ambient. | Use Scenario: Clamping transient surges on USB VBUS line during hot-plug events. IC Role / Device Role / Timing Role: Passive overvoltage protector placed between VBUS and GND. Use Value: Limits peak voltage to ≤21.2 V, preventing damage to downstream 20 V-rated USB PHY ICs. |
| Low-Power RTOS Reference | Programmable Logic Supply Monitor |
Use Scenario: Generating precise 20 V reference for ADC input scaling in battery-powered IoT nodes. IC Role / Device Role / Timing Role: Shunt regulator supplying clean reference to 12-bit SAR ADC. Use Value: Enables <1 LSB INL error due to <0.1% voltage drift over operating temperature range. | Use Scenario: Monitoring 24 V industrial control rail to trigger FPGA reset if voltage drops below 20 V. IC Role / Device Role / Timing Role: Threshold detector via resistor divider into comparator input. Use Value: Provides 20 V ±1% trip point with <5 µA supply current draw from monitored rail. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5242B | 20 V nominal, ±5%, 350 mW rating, 22 Ω Zz at 20 mA, SOT-23 | Higher power handling; slightly higher Zz; same pinout | Select when >250 mW derating margin is required for intermittent surge conditions |
| BZX84-C20LT1G | 20 V nominal, ±5%, 300 mW rating, 20 Ω Zz at 20 mA, SOT-23 | ON Semiconductor second-source variant with identical electrical specs and tighter thermal spec (RθJA = 400°C/W) | Preferred for new designs requiring extended lifecycle support and RoHS-compliant packaging |
Compared with MMBZ5242B and BZX84-C20LT1G, the BZX84C20 offers identical voltage regulation performance at lower cost but with reduced power margin and higher thermal resistance-making it optimal for space-constrained, low-duty-cycle biasing where 250 mW suffices.
Availability
BZX84C20 is available at Aetrix Electronics and suitable for industrial sensor biasing, USB port protection, low-power ADC reference, and programmable logic supply monitoring requiring stable component supply and consistent parametric performance across production lots.
Supply support for BZX84C20 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 (formerly Fairchild Semiconductor) is a global semiconductor supplier specializing in power management, analog, sensor, and discrete devices for automotive, industrial, and cloud power applications.
The BZX84C20 belongs to the BZX84C series of general-purpose Zener diodes designed for precision voltage regulation and overvoltage protection in space-constrained, low-power electronic systems.
FAQ
What is the nominal zener voltage and tolerance of the BZX84C20?
The BZX84C20 has a nominal zener voltage of 20 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 18.8 V and 21.2 V when tested at 5 mA. This specification is guaranteed per the datasheet's Electrical Characteristics table and applies across the full operating temperature range of –55°C to +150°C.
What is the maximum power dissipation rating for the BZX84C20?
The BZX84C20 is rated for 250 mW power dissipation at an ambient temperature of 25°C when mounted on a standard FR-4 PCB (76.2 mm × 114.3 mm). Derating is required above 25°C at 2.15 mW/°C, based on its 465°C/W junction-to-ambient thermal resistance.
Does the BZX84C20 have a specified zener impedance, and at what test condition?
Yes, the BZX84C20 has a typical zener impedance (ZZ) of 20 Ω measured at 20 mA forward current. This value reflects the dynamic resistance across the breakdown knee and directly affects regulation stability under varying load conditions in voltage reference applications.
What is the reverse leakage current specification for the BZX84C20?
The BZX84C20 exhibits a maximum reverse leakage current (IR) of 0.05 µA when biased at 14 V (VR), as specified in the Electrical Characteristics table. This ultra-low leakage supports energy-efficient operation in battery-powered and always-on monitoring circuits.
Is the BZX84C20 compatible with standard SOT-23 pick-and-place equipment?
Yes, the BZX84C20 uses the industry-standard SOT-23 package with 1.3 mm × 2.9 mm footprint and gull-wing leads, fully compatible with automated surface-mount assembly processes including reflow soldering per J-STD-020 guidelines. Its cathode marking aligns with JEDEC MO-178AB mechanical drawings.
BZX84C20 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 20 V
- Tolerance:
- ±6%
- Power - Max:
- 350 mW
- Impedance (Max) (Zzt):
- 55 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 14 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BZX84C20 FAQ
1.How can I place an order for BZX84C20 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C20 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 BZX84C20 reliable?
The price and inventory of BZX84C20 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84C20 is usually 5 days.
3.What payment methods are accepted for BZX84C20?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C20 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C20?
BZX84C20 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C20 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 BZX84C20?
For technical support, including BZX84C20 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C20 requirements.
6.How does Aetrix verify that BZX84C20 is sourced from the original manufacturer or authorized distributors?
All BZX84C20 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 BZX84C20 meets industry standards.
7.What is the process for return or replacement of BZX84C20?
All BZX84C20 units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C20, 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 BZX84C20 part is unused and in its original packaging.
Return procedure for BZX84C20:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84C20 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…
