My Inquiry
My Account
Nexperia USA Inc. BZX8450-C33-QR
- Part No.:
- BZX8450-C33-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX8450-C33-QR.pdf
- Description:
- DIODE ZENER 33V 250MW TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,568
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BZX8450-C33-QR from Nexperia is a low-current Zener voltage regulator diode in SOT23 package, designed for precision voltage reference and biasing in automotive and portable electronics. It delivers a nominal 33 V regulation at 50 µA test current, with ±5 % tolerance, 250 mW total power dissipation, and 31.35 V to 34.65 V working voltage range. It is AEC-Q101 qualified and optimized for low-leakage, low-noise operation in battery-powered systems.
For engineers reviewing the BZX8450-C33-QR datasheet, BZX8450-C33-QR pinout, BZX8450-C33-QR application, or BZX8450-C33-QR equivalent, this page provides verified electrical characteristics, thermal behavior, automotive qualification status, SOT23 terminal mapping, and real-world use cases in voltage clamping, reference generation, and overvoltage protection circuits.
Technical Context
This device operates as a reverse-biased Zener diode with a specified breakdown voltage of 33 V at IZ = 50 µA, exhibiting a differential resistance of 325 Ω at 5 mA and a temperature coefficient of +0.05 mV/K. Its low test current enables stable regulation in ultra-low-power circuits where bias current must be minimized.
The BZX8450-C33-QR features intentional minor leakage current rise per AN90031 to improve switching speed and reduce noise-distinct from standard B-series variants-and is rated for junction temperatures up to 150 °C with Rth(j-a) = 500 K/W on FR4 PCB.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 33 V at IZ = 50 µA - defines precise regulation point under minimal bias |
| Voltage Tolerance | ±5 % (31.35 V to 34.65 V) - ensures predictable clamping across production lots |
| Power Dissipation | 250 mW at Tamb ≤ 25 °C - limits thermal rise on standard FR4 PCB with single-sided copper |
| Differential Resistance | 325 Ω at IZ = 5 mA - determines output impedance and load regulation sensitivity |
| Forward Voltage | ≤ 0.9 V at IF = 10 mA - enables low-loss forward conduction during transient events |
| Junction Temperature | −55 °C to +150 °C - supports operation in under-hood automotive environments |
| AEC-Q101 Qualified | Yes - validated for automotive-grade reliability including temperature cycling and HTRB |
Pinout & Package
Package: SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch), optimized for automated assembly and thermal performance on FR4 PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Connects to lower-potential node in reverse-bias configuration; carries forward current during surge events |
| 2 | Not Connected (n.c.) | Internally unconnected; must remain floating-no PCB trace or solder mask required |
| 3 | Cathode (K) | Connects to higher-potential node; primary terminal for Zener breakdown and voltage reference output |
Key Features
| Feature | Design Value |
|---|---|
| Low Test Current Operation | Specified at 50 µA - enables stable regulation in micropower sensor nodes and standby circuits |
| Optimized Leakage Profile | Intentional minor IR rise per AN90031 - reduces switching noise and improves transient response vs. B-series |
| Automotive Qualification | AEC-Q101 compliant - qualified for engine control units, body electronics, and ADAS subsystems |
| Thermal Performance | Rth(j-sp) = 330 K/W to cathode solder point - supports reliable power handling in compact layouts |
| Small-Signal Stability | Capacitance ≤ 45 pF at VR = 0 V, f = 1 MHz - minimizes high-frequency coupling in precision references |
Applications
| Automotive Sensor Biasing | Portable Device Voltage Reference |
|---|---|
Use Scenario: Providing stable 33 V bias to analog front-ends in engine knock sensors and exhaust gas oxygen sensors. IC Role / Device Role / Timing Role: Zener voltage reference source maintaining ADC input range integrity under wide ambient temperature swings. Use Value: Enables accurate sensor signal conditioning without external regulators, leveraging AEC-Q101 reliability and low 50 µA operating current. |
Use Scenario: Generating a clean 33 V reference for Li-ion battery protection ICs in wireless earbuds and wearables. IC Role / Device Role / Timing Role: Precision shunt regulator establishing overvoltage trip threshold for battery management circuitry. Use Value: Delivers tight ±5 % tolerance and low 45 pF capacitance to avoid signal distortion in high-impedance sensing paths. |
| Industrial Signal Conditioning | Low-Power MCU Reset Circuit |
Use Scenario: Clamping analog signal rails in 4–20 mA transmitter modules exposed to ESD and supply transients. IC Role / Device Role / Timing Role: Reverse-biased Zener clamp absorbing fast transients while maintaining signal fidelity. Use Value: Withstands non-repetitive 40 W peak power surges (tp = 100 µs) and exhibits <0.05 µA IR at 27 V, minimizing loading. |
Use Scenario: Setting reset threshold for 3.3 V microcontrollers in smart home hubs powered by 36 V DC adapters. IC Role / Device Role / Timing Role: Zener-based voltage monitor triggering POR circuit when input drops below 31.35 V. Use Value: Guarantees deterministic reset behavior across −40 °C to +125 °C via AEC-Q101 thermal validation and low tempco (+0.05 mV/K). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX8450-B33-Q | ±2 % tolerance (32.34 V–33.66 V), lower leakage, no intentional IR rise | Better accuracy for calibration-critical references; slower switching, higher noise floor | Select when absolute voltage precision outweighs transient noise performance |
| MMSZ5257ET1G | 33 V ±5 %, 500 mW rating, SOD-123 package, higher rdiff (700 Ω) | Larger footprint, higher thermal resistance, not AEC-Q101 qualified | Choose only for non-automotive, cost-sensitive designs where board space and qualification are secondary |
Compared with BZX8450-B33-Q, the C33-Q trades tighter tolerance for faster switching and lower noise; versus MMSZ5257ET1G, it offers automotive qualification, smaller SOT23 footprint, and superior thermal performance on standard PCBs.
Availability
BZX8450-C33-QR is available at Aetrix Electronics and suitable for automotive sensor biasing, portable device voltage reference, and industrial signal conditioning requiring stable component supply, long-term lifecycle support, and AEC-Q101 compliance.
Supply support for BZX8450-C33-QR 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 essential efficiency-enhancing components, delivering high-performance, reliable, and scalable solutions for automotive, industrial, and consumer markets.
The BZX8450-Q series belongs to Nexperia's automotive-qualified Zener diode product line, engineered specifically for low-current, low-noise voltage regulation in harsh-environment electronics where precision, reliability, and small form factor are critical.
FAQ
What is the maximum reverse voltage before breakdown for BZX8450-C33-QR?
The BZX8450-C33-QR has a nominal Zener voltage of 33 V at IZ = 50 µA, with guaranteed minimum and maximum values of 31.35 V and 34.65 V respectively. Breakdown occurs within this range depending on test current and temperature; it is not rated for sustained operation above 34.65 V in regulation mode.
Can BZX8450-C33-QR replace BZX8450-B33-Q in existing designs?
Yes, but with trade-offs: both share identical package, pinout, and nominal voltage, but the C33-Q has ±5 % tolerance and intentional leakage optimization for noise reduction, whereas the B33-Q offers ±2 % tolerance and lower leakage. Verify if system-level accuracy or transient noise performance dominates the design requirement.
Is the n.c. pin (Pin 2) required to be grounded or left floating?
Pin 2 is internally not connected and must remain electrically floating-no PCB trace, solder mask opening, or grounding is permitted. Connecting it risks internal damage or unpredictable leakage behavior, as confirmed in Nexperia's official pinning diagram and package outline documentation.
How does thermal resistance impact power derating in real PCB layouts?
With Rth(j-a) = 500 K/W on standard FR4, power must be derated linearly above 25 °C ambient: at 85 °C, max dissipation drops to 150 mW. For continuous 250 mW operation, ensure adequate copper area on cathode pad (Rth(j-sp) = 330 K/W) and avoid thermal isolation of Pin 3 in layout.
BZX8450-C33-QR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 250 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 25 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BZX8450-C33-QR FAQ
1.How can I place an order for BZX8450-C33-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX8450-C33-QR 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-C33-QR reliable?
The price and inventory of BZX8450-C33-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX8450-C33-QR is usually 5 days.
3.What payment methods are accepted for BZX8450-C33-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX8450-C33-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX8450-C33-QR?
BZX8450-C33-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX8450-C33-QR 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-C33-QR?
For technical support, including BZX8450-C33-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX8450-C33-QR requirements.
6.How does Aetrix verify that BZX8450-C33-QR is sourced from the original manufacturer or authorized distributors?
All BZX8450-C33-QR 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-C33-QR meets industry standards.
7.What is the process for return or replacement of BZX8450-C33-QR?
All BZX8450-C33-QR units undergo pre-shipment inspection (PSI). If there is an issue with BZX8450-C33-QR, 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-C33-QR part is unused and in its original packaging.
Return procedure for BZX8450-C33-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX8450-C33-QR 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
