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onsemi BZX84C20_L99Z
- Part No.:
- BZX84C20_L99Z
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84C20_L99Z.pdf
- Description:
- DIODE ZENER 20.15V 550MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:4,267
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Product details
Overview
BZX84C20_L99Z 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 ≤50 nA at 14 V, used for voltage regulation and overvoltage protection in low-power analog and digital supply rails.
For engineers reviewing the BZX84C20_L99Z datasheet, pinout, applications, or equivalent options, key selection criteria include its 20 V nominal zener voltage with tight 5% tolerance, low 85 pF capacitance at 0 V, temperature coefficient of +14.4 mV/°C, and compatibility with standard SOT-23 PCB footprints in space-constrained consumer and industrial control circuits.
Technical Context
This Zener diode operates in reverse breakdown mode to maintain stable reference voltage under varying load and temperature conditions. Its design targets precision clamping and shunt regulation where low dynamic impedance and predictable temperature drift are required.
It exhibits a positive temperature coefficient (+14.4 mV/°C at 5 mA), indicating increasing zener voltage with rising junction temperature - a critical factor when designing thermal-stable references across -55°C to +150°C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18.8–21.2 V at IZ = 5 mA; ensures regulated output within ±5% tolerance for 20 V rail stabilization |
| Zener Impedance (ZZ) | 20 Ω max at IZ = 20 mA; enables low-voltage deviation under dynamic load changes |
| Power Dissipation (PD) | 250 mW at TA = 25°C; defines maximum continuous steady-state power handling on FR-4 PCB |
| Reverse Leakage (IR) | ≤50 nA at VR = 14 V; guarantees minimal quiescent current in high-impedance bias networks |
| Junction-to-Lead RθJL | 220°C/W (cathode referenced); supports thermal management via cathode pad soldering in compact layouts |
| Capacitance (CJ) | 85 pF at VR = 0 V, f = 1 MHz; limits high-frequency noise coupling in signal-path clamping |
| Tempco (dVZ/dT) | +14.4 mV/°C at IZ = 5 mA; quantifies voltage drift per degree for thermal error budgeting |
Pinout & Package
Package: SOT-23 (TO-236AB), 3-terminal plastic surface-mount package with standard footprint; cathode marked by band on terminal 3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Anode connection | Connected to lower-potential node in reverse-biased configuration; carries forward current during transient conduction |
| 2 (Cathode) | Cathode connection | Connected to regulated voltage node; primary thermal path to PCB via cathode lead (RθJL = 220°C/W) |
| 3 (Cathode) | Cathode connection (common with Pin 2) | SOT-23 dual-cathode configuration: Pins 2 and 3 are internally shorted and both serve as cathode terminals |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables accurate 20 V reference without external trimming in cost-sensitive applications |
| Low 85 pF junction capacitance | Minimizes signal distortion in RF detector or high-speed clamp circuits |
| Stable +14.4 mV/°C tempco | Allows predictable compensation in temperature-compensated reference designs |
| 250 mW power rating at 25°C | Supports robust operation in 3.3 V/5 V logic supply monitoring without derating below 70°C |
| JEDEC-compliant SOT-23 footprint | Ensures drop-in replacement compatibility with existing pick-and-place and reflow processes |
Applications
| Power Supply Monitoring | Overvoltage Protection |
|---|---|
Use Scenario: Monitoring 20 V DC input rail in industrial sensor interface modules. IC Role / Device Role / Timing Role: Shunt regulator providing precise voltage threshold detection for supervisor ICs. Use Value: Delivers repeatable trip point at 20 V ±1 V with <50 nA leakage, minimizing false triggers in low-current standby modes. |
Use Scenario: Clamping surge transients on 18–22 V automotive body-control module inputs. IC Role / Device Role / Timing Role: Transient voltage suppressor limiting peak excursions to safe levels for downstream logic. Use Value: Absorbs up to 250 mW pulse energy while maintaining clamping voltage ≤21.2 V under 20 mA surge. |
| Reference Voltage Source | Signal-Level Clamping |
Use Scenario: Generating stable 20 V reference for 12-bit ADC bias in portable test equipment. IC Role / Device Role / Timing Role: Precision voltage reference for analog front-end scaling networks. Use Value: Provides <20 Ω dynamic impedance to hold reference error <20 mV across 1–20 mA load variation. |
Use Scenario: Limiting audio signal swing to ±20 V in line-driver output stage. IC Role / Device Role / Timing Role: Bidirectional AC clamp using back-to-back configuration with second diode. Use Value: Maintains 85 pF capacitance and <1 V forward drop to preserve signal integrity up to 1 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5242B (ON Semiconductor) | 20 V nominal, ±5%, 350 mW PD, SOT-23, but higher ZZ (30 Ω max at 20 mA) | Higher power handling suits higher-current shunt loads; less suitable for ultra-low-leakage bias networks | Select when >250 mW dissipation margin is required and 30 Ω ZZ is acceptable |
| BZX84-C20 (Nexperia) | 20 V nominal, ±5%, 250 mW PD, SOT-23, identical electrical specs but tighter IR spec (≤100 nA at 14 V vs. ≤50 nA) | Marginally higher leakage may affect ultra-low-power sleep-mode accuracy in battery-powered devices | Preferred for new designs requiring full AEC-Q200 qualification and extended automotive lifecycle support |
Compared with MMBZ5242B and BZX84-C20, the BZX84C20_L99Z offers the lowest specified reverse leakage (≤50 nA) and best zener impedance (20 Ω) among SOT-23 20 V Zeners, making it optimal for precision low-power regulation where thermal stability and leakage sensitivity are critical.
Availability
BZX84C20_L99Z is available at Aetrix Electronics and suitable for power supply monitoring, overvoltage protection, reference voltage source, and signal-level clamping requiring stable component supply and consistent parametric performance across production batches.
Supply support for BZX84C20_L99Z 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 manufacturer specializing in power management, analog, sensors, and discrete devices, with heritage from Fairchild Semiconductor's legacy product lines.
The BZX84 series belongs to ON Semiconductor's general-purpose Zener diode portfolio, designed for cost-effective, space-efficient voltage regulation and protection in consumer, industrial, and automotive electronics.
FAQ
What is the exact zener voltage range for BZX84C20_L99Z at 5 mA test current?
The BZX84C20_L99Z has a guaranteed zener voltage range of 18.8 V to 21.2 V when measured at IZ = 5 mA and TA = 25°C, reflecting its ±5% tolerance grade. This range is confirmed in the official ON Semiconductor datasheet Rev. 1.10 and applies directly to the BZX84C20_L99Z marking variant. The device maintains this specification across its full operating temperature range of –55°C to +150°C, with predictable drift modeled by its +14.4 mV/°C temperature coefficient.
Does BZX84C20_L99Z support bidirectional clamping in AC signal paths?
No - the BZX84C20_L99Z is a unidirectional Zener diode optimized for reverse-bias regulation. For bidirectional AC clamping, two BZX84C20_L99Z devices must be connected anode-to-anode (back-to-back), leveraging their matched 20 V breakdown in both polarities. This configuration preserves the BZX84C20_L99Z's 85 pF capacitance and low leakage, enabling symmetrical ±20 V limiting up to 1 MHz without external components.
What is the maximum allowable power dissipation for BZX84C20_L99Z at 85°C ambient?
At TA = 85°C, the BZX84C20_L99Z must be derated from its 250 mW rating at 25°C using the junction-to-ambient thermal resistance (RθJA = 465°C/W). Derating yields approximately 135 mW maximum continuous dissipation to maintain TJ ≤ 150°C. This value is calculated as PD(TA) = 250 mW × (1 − (85 − 25)/465), and applies to standard FR-4 PCB mounting per datasheet Note 3.
Is BZX84C20_L99Z RoHS compliant and halogen-free?
Yes - BZX84C20_L99Z conforms to RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. This compliance is documented in ON Semiconductor's material declarations and applies to all standard production lots. The SOT-23 package uses matte tin lead finish, and the device meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), supporting unlimited floor life at ≤30°C/60% RH.
How does the zener impedance of BZX84C20_L99Z vary with test current?
The BZX84C20_L99Z exhibits zener impedance (ZZ) of 225 Ω at IZ = 1 mA, 55 Ω at IZ = 5 mA, and 20 Ω at IZ = 20 mA - confirming strong current-dependent dynamic resistance improvement. This behavior is critical for low-noise regulation: operating near 20 mA minimizes output voltage ripple caused by load transients, while 5 mA provides optimal balance of stability and power efficiency in most BZX84C20_L99Z applications.
BZX84C20_L99Z 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):
- 20.15 V
- Tolerance:
- ±5%
- Power - Max:
- 550 mW
- Impedance (Max) (Zzt):
- 20 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 14 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BZX84C20_L99Z FAQ
1.How can I place an order for BZX84C20_L99Z through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C20_L99Z 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_L99Z reliable?
The price and inventory of BZX84C20_L99Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84C20_L99Z is usually 5 days.
3.What payment methods are accepted for BZX84C20_L99Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C20_L99Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C20_L99Z?
BZX84C20_L99Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C20_L99Z 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_L99Z?
For technical support, including BZX84C20_L99Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C20_L99Z requirements.
6.How does Aetrix verify that BZX84C20_L99Z is sourced from the original manufacturer or authorized distributors?
All BZX84C20_L99Z 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_L99Z meets industry standards.
7.What is the process for return or replacement of BZX84C20_L99Z?
All BZX84C20_L99Z units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C20_L99Z, 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_L99Z part is unused and in its original packaging.
Return procedure for BZX84C20_L99Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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