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Nexperia USA Inc. BZX8450-B18R
- Part No.:
- BZX8450-B18R
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX8450-B18R.pdf
- Description:
- DIODE ZENER 18V 250MW TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,529
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Product details
Overview
BZX8450-B18R from Nexperia is a low-current Zener voltage regulator diode in SOT23 package, designed for precision voltage reference and biasing in ultra-low-power circuits. It delivers a nominal 18 V regulation at 50 µA test current, with ±2 % tolerance, 225 Ω dynamic impedance at 5 mA, and 0.05 µA reverse leakage at 13.6 V, enabling stable operation in portable battery-powered sensors and microcontroller reset circuits.
For engineers reviewing the BZX8450-B18R datasheet, BZX8450-B18R pinout, BZX8450-B18R application, or BZX8450-B18R equivalent, this page provides verified electrical characteristics, thermal resistance (330 K/W to solder point), SOT23 terminal mapping, and direct replacement guidance for low-power Zener-based regulation.
Technical Context
This device operates as a two-terminal shunt voltage regulator, maintaining a stable 17.6–18.4 V output across its cathode-anode terminals under reverse-bias conditions. Its specified test current of 50 µA enables accurate regulation in standby or sleep-mode circuits where quiescent current must remain below 100 µA.
The BZX8450-B18R features intentional minor leakage optimization per AN90031, reducing noise and improving switching response versus standard Zeners. Its 250 mW total power dissipation is rated on FR4 PCB with single-sided 70 µm copper, and junction temperature is limited to 150 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 18 V (min 17.6 V, max 18.4 V at IZ = 50 µA); defines precise reference level for low-current bias networks |
| Tolerance | ±2 % (B-series); ensures tight voltage accuracy without post-production trimming |
| Differential Resistance | 225 Ω (max at IZ = 5 mA); determines regulation stiffness under load variation |
| Reverse Leakage Current | 0.05 µA max at VR = 13.6 V; enables nanoamp-level standby current in battery-critical designs |
| Forward Voltage | 0.9 V max at IF = 10 mA; supports reliable anode-side clamping or polarity detection |
| Total Power Dissipation | 250 mW (Tamb ≤ 25 °C on FR4 PCB); sets maximum continuous power handling in compact layouts |
| Junction-to-Solder-Point Thermal Resistance | 330 K/W; informs thermal design margin when cathode tab is soldered to copper pour |
Pinout & Package
SOT23 plastic surface-mount package: 2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch, 3-terminal configuration with exposed cathode tab for thermal conduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Positive terminal for forward conduction; connected to lower-potential node in shunt regulation |
| 2 | Not Connected (n.c.) | Internally isolated; must remain unconnected on PCB to avoid parasitic coupling or mechanical stress |
| 3 | Cathode (K) | Regulated output node; ties to voltage rail being stabilized and serves as primary thermal path to PCB |
Key Features
| Feature | Design Value |
|---|---|
| Low-test-current regulation | Specified at 50 µA - enables use in µA-level bias chains without compromising accuracy |
| Optimized leakage profile | Intentional minor rise per AN90031 - reduces high-frequency noise and improves transient response vs. legacy Zeners |
| Thermal performance | Rth(j-sp) = 330 K/W - allows predictable derating when cathode is soldered to thermal pad or copper plane |
| Package compatibility | SOT23 footprint - supports automated placement and reflow, with standardized land pattern per Fig. 10 (reflow) |
Applications
| Microcontroller Reset Circuit | Portable Sensor Bias Network |
|---|---|
Use Scenario: Generating a clean, low-drift reset threshold for ARM Cortex-M0+ MCUs operating from coin-cell batteries. IC Role / Device Role / Timing Role: Shunt Zener providing stable 18 V reference to RC network feeding reset supervisor IC. Use Value: ±2 % tolerance and 0.05 µA leakage ensure reset assertion remains valid over full battery discharge (1.8–3.0 V supply range). |
Use Scenario: Supplying regulated bias voltage to MEMS pressure sensor analog front-end in wearable health monitors. IC Role / Device Role / Timing Role: Low-current Zener reference stabilizing op-amp gain-setting resistors and ADC reference divider. Use Value: 50 µA test current matches sensor's sleep-mode current budget, avoiding unnecessary power overhead. |
| Low-Power Analog Signal Conditioning | EEPROM Write-Voltage Clamp |
Use Scenario: Setting fixed bias point for rail-to-rail input op-amps in battery-operated environmental data loggers. IC Role / Device Role / Timing Role: Voltage reference source defining common-mode input level for differential amplifiers. Use Value: 225 Ω dynamic impedance minimizes drift under varying signal-source impedance (≤10 kΩ). |
Use Scenario: Clamping programming voltage to 18 V during EEPROM write cycles in industrial control modules. IC Role / Device Role / Timing Role: Overvoltage protection element limiting VPP rail to safe level during flash programming pulses. Use Value: 250 mW power rating sustains brief 100 µs pulses up to 40 W peak (per Fig. 1), preventing latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18 | ±5 % tolerance, higher leakage (0.1 µA at 13.6 V), 200 Ω rdiff at 5 mA | Acceptable where cost sensitivity outweighs precision; less suitable for sub-µA standby systems | Select for cost-driven consumer electronics where 18 V ±5 % meets functional safety margins |
| MMSZ5245B | Same 18 V nominal, ±5 %, but rated at 500 mW and uses SOD-123 package (larger footprint, higher thermal mass) | Preferred for higher-power or thermally demanding environments; incompatible with space-constrained SOT23 layouts | Choose when board layout allows SOD-123 and system requires >250 mW continuous dissipation headroom |
Compared with BZX8450-B18R, the BZX84-C18 trades accuracy for cost and the MMSZ5245B trades miniaturization for thermal robustness-making the BZX8450-B18R optimal for space- and current-constrained precision biasing.
Availability
BZX8450-B18R is available at Aetrix Electronics and suitable for microcontroller reset circuits, portable sensor bias networks, low-power analog signal conditioning, and EEPROM write-voltage clamp applications requiring stable component supply and guaranteed traceability.
Supply support for BZX8450-B18R 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 energy-efficient components.
The BZX8450 series belongs to Nexperia's low-current Zener portfolio, engineered specifically for ultra-low-power voltage reference and biasing in battery-operated and space-constrained electronics.
FAQ
What is the maximum reverse voltage before breakdown for BZX8450-B18R?
The BZX8450-B18R has a nominal Zener voltage of 18 V with a guaranteed range of 17.6 V to 18.4 V at 50 µA test current. Breakdown occurs within this band; it is not rated for stable operation above 18.4 V. Exceeding 20.4 V risks irreversible damage per absolute maximum ratings.
Can BZX8450-B18R be used in series or parallel configurations?
No-this device is a single-element Zener diode with no internal series resistance or thermal matching. Parallel connection causes current hogging due to parameter spread; series use introduces unpredictable voltage division. Use only as a single shunt regulator per circuit node.
Is the n.c. pin (Pin 2) electrically isolated or internally tied?
Pin 2 is confirmed as not connected (n.c.) per Table 2 and Figure 9: it has no internal bond wire or silicon connection. It must remain unconnected on PCB to prevent mechanical stress or unintended coupling-no pull-up, pull-down, or grounding is permitted.
How does the "intentional minor rise of leakage current" affect circuit noise?
Per AN90031, the controlled leakage increase reduces junction capacitance modulation and suppresses avalanche noise spikes, yielding lower broadband RMS noise (typ. <10 µV/√Hz) compared to standard Zeners-critical for precision analog front-ends and low-phase-noise oscillators.
BZX8450-B18R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX8450
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 250 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 13.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BZX8450-B18R FAQ
1.How can I place an order for BZX8450-B18R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX8450-B18R 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 BZX8450-B18R reliable?
The price and inventory of BZX8450-B18R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX8450-B18R is usually 5 days.
3.What payment methods are accepted for BZX8450-B18R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX8450-B18R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX8450-B18R?
BZX8450-B18R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX8450-B18R 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 BZX8450-B18R?
For technical support, including BZX8450-B18R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX8450-B18R requirements.
6.How does Aetrix verify that BZX8450-B18R is sourced from the original manufacturer or authorized distributors?
All BZX8450-B18R 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 BZX8450-B18R meets industry standards.
7.What is the process for return or replacement of BZX8450-B18R?
All BZX8450-B18R units undergo pre-shipment inspection (PSI). If there is an issue with BZX8450-B18R, 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 BZX8450-B18R part is unused and in its original packaging.
Return procedure for BZX8450-B18R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX8450-B18R 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
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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