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Nexperia USA Inc. BZX38450-B20X
- Part No.:
- BZX38450-B20X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-B20X.pdf
- Description:
- DIODE ZENER 20V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:8,225
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Product details
Overview
BZX38450-B20X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, designed for precision biasing and voltage reference in ultra-low-power circuits. It delivers a nominal 20 V regulation at 50 µA test current, with ±2 % tolerance, 300 mW total power dissipation, and 15.2 Ω differential resistance at 5 mA - ideal for battery-powered sensor nodes and portable instrumentation.
For engineers reviewing the BZX38450-B20X datasheet, BZX38450-B20X pinout, BZX38450-B20X application, or BZX38450-B20X equivalent, key selection criteria include its low 50 µA regulation test current, tight ±2 % tolerance, SOD323 footprint compatibility, and thermal resistance of 415 K/W in free air - critical for space-constrained, thermally sensitive designs.
Technical Context
This Zener diode operates in reverse breakdown mode with a specified working voltage of 19.0 V to 21.0 V at IZ = 50 µA. Its temperature coefficient is +0.4 mV/K, indicating stable regulation over temperature, and it exhibits 15.2 Ω differential resistance at 5 mA, enabling predictable dynamic response in feedback paths.
The device supports continuous forward current up to 250 mA and withstands non-repetitive peak reverse power surges of 40 W (100 µs pulse), while maintaining junction temperatures ≤ 150 °C. Its 220 pF capacitance at 0 V and 1 MHz makes it suitable for low-frequency stabilization without signal coupling concerns.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 20 V - precise reference point for 19.0–21.0 V regulation at 50 µA |
| Tolerance | ±2 % - enables high-accuracy analog sensing and ADC reference stability |
| Differential Resistance | 15.2 Ω at 5 mA - ensures minimal output voltage shift under load variation |
| Power Dissipation | 300 mW at Tamb ≤ 25 °C - defines maximum steady-state thermal budget on FR4 PCB |
| Forward Voltage | 0.9 V at 10 mA - limits conduction loss when used in series-bias configurations |
| Junction Temperature | 150 °C max - sets upper thermal limit for reliability in sealed enclosures |
| Thermal Resistance (j-a) | 415 K/W - determines temperature rise per watt in unforced-air environments |
Pinout & Package
SOD323 (SC-76) surface-mount plastic package: 1.7 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch, cathode marked by bar on top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; marking bar identifies this terminal |
| 2 | Anode (A) | Connected to ground or lower-potential rail; reverse-biased during regulation |
Key Features
| Feature | Design Value |
|---|---|
| Low test current operation | Specified at 50 µA - enables use in nanoamp-level standby circuits without compromising regulation accuracy |
| Tight voltage tolerance | ±2 % - reduces calibration overhead in precision voltage monitoring systems |
| Optimized leakage profile | Intentional minor leakage rise per AN90031 - improves switching speed and reduces noise in transient-sensitive references |
| Small-footprint packaging | SOD323 outline - saves board area in wearables and IoT edge nodes where space is constrained |
| Robust surge handling | 40 W non-repetitive peak reverse power (100 µs) - protects against ESD-induced transients in unshielded interfaces |
Applications
| Portable Gas Sensor Calibration | Medical Pulse Oximeter Reference |
|---|---|
Use Scenario: Stable 20 V reference for analog front-end gain calibration in battery-operated CO₂ sensors. IC Role / Device Role / Timing Role: Zener voltage reference providing fixed bias to op-amp input stage. Use Value: ±2 % tolerance and 15.2 Ω rdiff ensure <±10 mV drift across 0–50 °C, meeting ISO 80601-2-56 accuracy requirements. |
Use Scenario: Low-power LED driver bias supply in disposable fingertip oximeters. IC Role / Device Role / Timing Role: Current-limiting Zener shunt regulating LED forward voltage. Use Value: 50 µA test current enables operation from coin-cell batteries for >2 years without significant voltage droop. |
| Industrial RTD Signal Conditioning | Smart Meter Auxiliary Power Rail |
Use Scenario: Excitation voltage source for 3-wire Pt100 RTD bridges in DIN-rail mounted transmitters. IC Role / Device Role / Timing Role: Precision shunt regulator stabilizing bridge excitation current source. Use Value: +0.4 mV/K tempco and 415 K/W Rth(j-a) limit thermal drift to <0.1 % FS over −40 to +85 °C ambient. |
Use Scenario: Standby power rail generation from mains-derived DC in energy meters with wake-on-event capability. IC Role / Device Role / Timing Role: Low-quiescent shunt regulator maintaining microcontroller reset threshold. Use Value: 300 mW Ptot and SOD323 footprint allow integration into compact meter PCBs without heatsinking. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-C20 | ±5 % tolerance, higher 20 Ω rdiff at 5 mA, same SOD323 package | Acceptable where cost sensitivity outweighs precision needs (e.g., non-critical power sequencing) | Select when ±5 % regulation error is permissible and BOM cost reduction is prioritized |
| MMSZ5248B | 20 V nominal, ±5 %, 22 Ω rdiff, SOD-123 package (larger footprint, 2.5 mm × 1.3 mm) | Requires PCB layout revision due to different pad geometry and thermal profile | Choose only if existing design uses SOD-123 and requalification time prohibits footprint change |
Compared with BZX38450-B20X, BZX384-C20 trades precision for cost in non-critical rails, while MMSZ5248B introduces mechanical incompatibility despite matching voltage - making BZX38450-B20X the optimal choice for new designs demanding ±2 % accuracy in minimal area.
Availability
BZX38450-B20X is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor transmitters, smart utility meters, and battery-backed instrumentation requiring stable component supply with guaranteed long-term continuity.
Supply support for BZX38450-B20X 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
Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified and industrial-grade components.
The BZX38450 series belongs to Nexperia's precision low-current Zener portfolio, engineered specifically for ultra-low-power voltage reference and biasing in space- and energy-constrained applications.
FAQ
What is the maximum continuous reverse current the BZX38450-B20X can regulate at 20 V?
The device is rated for continuous operation at 50 µA test current, but its absolute maximum forward current is 250 mA. For Zener regulation, sustained reverse current must remain within power limits: at 20 V, maximum safe DC current is 15 mA (300 mW ÷ 20 V), assuming ambient ≤ 25 °C and no additional thermal derating.
Does the BZX38450-B20X require a series resistor in all applications?
Yes - a current-limiting resistor is mandatory to prevent thermal runaway. For example, with a 24 V supply and 20 V output, a 270 Ω resistor limits current to ~14.8 mA, staying within the 300 mW dissipation limit and ensuring stable regulation without exceeding junction temperature limits.
How does the ±2 % tolerance affect accuracy in a 12-bit ADC reference circuit?
At 20 V, ±2 % equals ±400 mV, or ±20 LSBs of full-scale range for a 0–20 V 12-bit ADC (LSB = 4.88 mV). To achieve sub-LSB reference error, external trimming or post-calibration is required - the tolerance reflects initial part-to-part variation, not drift over time or temperature.
Can BZX38450-B20X be used in parallel for higher power handling?
No - Zener diodes cannot be reliably paralleled due to mismatched breakdown voltages causing current hogging. Even with matched units, thermal coupling differences lead to instability. For >300 mW regulation, use a series-pass transistor with BZX38450-B20X as the reference element instead.
BZX38450-B20X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX38450
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 20 V
- Tolerance:
- ±2%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 55 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 15.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
BZX38450-B20X FAQ
1.How can I place an order for BZX38450-B20X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-B20X 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 BZX38450-B20X reliable?
The price and inventory of BZX38450-B20X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX38450-B20X is usually 5 days.
3.What payment methods are accepted for BZX38450-B20X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-B20X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-B20X?
BZX38450-B20X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-B20X 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 BZX38450-B20X?
For technical support, including BZX38450-B20X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-B20X requirements.
6.How does Aetrix verify that BZX38450-B20X is sourced from the original manufacturer or authorized distributors?
All BZX38450-B20X 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 BZX38450-B20X meets industry standards.
7.What is the process for return or replacement of BZX38450-B20X?
All BZX38450-B20X units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-B20X, 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 BZX38450-B20X part is unused and in its original packaging.
Return procedure for BZX38450-B20X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-B20X Tags
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MMBZ5240B-7-F
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
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MM5Z5V1ST1G
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SMAJ4744A-TP
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BZT52C3V6LP-7
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SMAZ12-13-F
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