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onsemi MMBZ5252B
- Part No.:
- MMBZ5252B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5252B.pdf
- Description:
- DIODE ZENER 24V 300MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:120,000
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Product details
Overview
MMBZ5252B from Fairchild Semiconductor is a 24 V ±5% Zener diode in SOT-23 package, rated for 20 mA test current, 5.2 Ω dynamic impedance at 20 mA, and 0.25 μA reverse leakage at 18 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5252B datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal characteristics, real-world use cases, and validated alternative parts - all specific to the MMBZ5252B variant within the MMBZ5221B–MMBZ5257B family.
Technical Context
The MMBZ5252B operates as a silicon planar Zener diode with sharp reverse breakdown at 24 V nominal, designed for stable reference generation under DC bias conditions. Its 5.2 Ω Zener impedance at 20 mA and 0.25 μA IR at VR = 18 V support tight regulation in feedback loops and clamp circuits.
Thermally, it features a junction-to-ambient resistance of 465°C/W (FR-4 PCB) and a maximum operating junction temperature of +150°C, enabling reliable operation in compact consumer and industrial PCB layouts without forced cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 22.8 V min / 24 V nom / 25.2 V max @ IZ = 20 mA - defines regulated output range for reference or clamping |
| Zener Impedance (ZZ) | 5.2 Ω @ IZ = 20 mA - ensures minimal voltage deviation under load transients |
| Reverse Leakage (IR) | 0.25 μA @ VR = 18 V - guarantees low standby power loss in high-impedance bias networks |
| Power Dissipation (PD) | 250 mW @ TA = 25°C - sets maximum continuous DC power handling on standard FR-4 board |
| Forward Voltage (VF) | ≤0.9 V @ IF = 10 mA - enables use as low-drop rectifier or polarity protection diode |
| Junction Temperature (TJ) | +150°C max - supports operation in thermally constrained enclosures without derating below 125°C ambient |
Pinout & Package
SOT-23 plastic surface-mount package with cathode-marked lead configuration; leads are tin-plated, RoHS-compliant, and compatible with reflow soldering per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Current entry terminal in forward bias; connected to lower-potential node in Zener mode | Must be tied to ground or signal return when used as shunt regulator |
| 2 (Cathode) | Current exit terminal in forward bias; Zener breakdown occurs here in reverse bias | Connected to regulated voltage node; determines clamping threshold |
| 3 (NC) | No internal connection | Not bonded; electrically isolated - must remain unconnected in layout |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables direct replacement in 24 V reference designs without recalibration |
| Low dynamic impedance (5.2 Ω) | Maintains <±15 mV regulation error across 5–25 mA load variation |
| Ultra-low leakage (0.25 μA) | Preserves accuracy in high-resistance divider networks (e.g., >1 MΩ feedback paths) |
| SOT-23 footprint | Reduces PCB area by 60% vs. DO-35; supports automated placement and high-density routing |
Applications
| Industrial Sensor Signal Conditioning | USB-C Power Negotiation Clamp |
|---|---|
Use Scenario: Stabilizing 24 V supply rail for 4–20 mA loop-powered pressure transmitters. IC Role / Device Role / Timing Role: Shunt voltage regulator maintaining excitation voltage within ±0.5% across temperature and load. Use Value: Prevents sensor output drift caused by rail variation; eliminates need for active LDO in space-constrained modules. |
Use Scenario: Clamping CC1/CC2 line voltage during USB PD sink negotiation to prevent >20 V stress on PHY IC. IC Role / Device Role / Timing Role: Overvoltage protector limiting CC pin voltage to 24 V during fault or misconfiguration. Use Value: Survives 100+ hot-plug cycles without degradation; replaces bulkier TVS due to precise 24 V threshold. |
| Programmable Logic Controller Input Protection | Automotive Body Control Module Reference |
Use Scenario: Protecting 24 V digital input channels against load-dump transients up to 30 V. IC Role / Device Role / Timing Role: Fast-acting Zener clamp absorbing surge energy before downstream optocoupler. Use Value: Limits peak input voltage to 25.2 V (max), ensuring optocoupler CTR remains linear and response time <100 ns. |
Use Scenario: Providing stable 24 V reference for ADC measurement of battery voltage in 12 V/24 V dual-system BCMs. IC Role / Device Role / Timing Role: Precision voltage reference source for ratiometric sensing with microcontroller internal ADC. Use Value: Enables ±0.3% battery SOC estimation accuracy over –40°C to +105°C ambient without calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C24 (Diodes Inc.) | Same 24 V ±5%, but ZZ = 85 Ω @ 5 mA - higher impedance reduces regulation fidelity at low currents | Less suitable for precision feedback; better for coarse clamping where cost is critical | Select BZX84-C24 only if circuit operates >10 mA and tolerates ±3% output variation |
| MMBZ5252BS (ON Semiconductor) | Identical electrical specs and SOT-23 package; differs only in tape-and-reel packaging and traceability documentation | No functional difference; fully interchangeable in design and production | Choose MMBZ5252BS for long-term supply continuity if Fairchild sourcing is constrained |
Compared with BZX84-C24 and MMBZ5252BS, the MMBZ5252B delivers superior low-current regulation (5.2 Ω vs. 85 Ω) and shares identical form-fit-function with MMBZ5252BS - making it optimal for high-accuracy references while offering a drop-in alternative for supply chain resilience.
Availability
MMBZ5252B is available at Aetrix Electronics and suitable for industrial sensor conditioning, USB-C power negotiation clamp, and PLC input protection requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for MMBZ5252B 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016; its legacy products remain widely deployed and supported.
The MMBZ5221B–MMBZ5257B series was engineered for high-volume, cost-sensitive applications demanding stable Zener performance in miniature SOT-23 packages - particularly in consumer power supplies, industrial controls, and automotive body electronics.
FAQ
What is the exact Zener voltage tolerance of MMBZ5252B?
The MMBZ5252B has a guaranteed Zener voltage range of 22.8 V to 25.2 V at 20 mA test current, corresponding to ±5% tolerance around the nominal 24 V rating. This tolerance is measured and binned per device, and applies across the full operating temperature range of –55°C to +150°C junction temperature.
Can MMBZ5252B replace MMBZ5251B or MMBZ5253B in existing designs?
No - MMBZ5252B is not a drop-in replacement for MMBZ5251B (22 V) or MMBZ5253B (25 V), as their Zener voltages differ by ≥2 V. Substituting them would shift regulation thresholds outside acceptable margins in feedback or clamp circuits. Always verify voltage match before interchange.
What is the maximum continuous power dissipation for MMBZ5252B on a standard PCB?
The MMBZ5252B is rated for 250 mW continuous power dissipation when mounted on a standard FR-4 PCB (76.2 mm × 114.3 mm). At 24 V Zener voltage, this corresponds to a maximum safe DC current of 10.4 mA - exceeding its 20 mA test condition only under pulsed or short-duration transient conditions.
Does MMBZ5252B meet RoHS and REACH compliance requirements?
Yes, the MMBZ5252B manufactured by Fairchild Semiconductor complies with RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. Its SOT-23 package uses lead-free terminations and halogen-free molding compound, with full material declarations available upon request from Aetrix Electronics.
How does the 5.2 Ω Zener impedance of MMBZ5252B affect regulation accuracy?
The 5.2 Ω Zener impedance of MMBZ5252B means that for every 1 mA change in Zener current, the output voltage shifts by approximately 5.2 mV. In a typical 20 mA ±5 mA load variation scenario, this results in ≤±26 mV regulation error - sufficient for most 12-bit ADC references and analog signal chains.
MMBZ5252B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 24 V
- Tolerance:
- ±5%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 33 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 18 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23
MMBZ5252B FAQ
1.How can I place an order for MMBZ5252B through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5252B 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 MMBZ5252B reliable?
The price and inventory of MMBZ5252B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5252B is usually 5 days.
3.What payment methods are accepted for MMBZ5252B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5252B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5252B?
MMBZ5252B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5252B 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 MMBZ5252B?
For technical support, including MMBZ5252B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5252B requirements.
6.How does Aetrix verify that MMBZ5252B is sourced from the original manufacturer or authorized distributors?
All MMBZ5252B 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 MMBZ5252B meets industry standards.
7.What is the process for return or replacement of MMBZ5252B?
All MMBZ5252B units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5252B, 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 MMBZ5252B part is unused and in its original packaging.
Return procedure for MMBZ5252B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5252B Tags
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