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onsemi MMBZ5240B
- Part No.:
- MMBZ5240B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5240B.pdf
- Description:
- DIODE ZENER 10V 250MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,511
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Product details
Overview
MMBZ5240B from Fairchild Semiconductor is a 10 V ±5% Zener diode in SOT-23 package, rated for 350 mW power dissipation, with 17 Ω dynamic impedance at 5 mA test current, 0.25 µA reverse leakage at 7.6 V, and maximum 0.9 V forward voltage at 10 mA - used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5240B datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, impedance stability across temperature, low leakage at rated VR, SOT-23 footprint compatibility, and junction temperature derating behavior up to +150°C.
Technical Context
The MMBZ5240B operates as a silicon planar passivated Zener diode optimized for stable voltage reference and clamping in space-constrained DC bias networks. Its 10 V nominal breakdown is specified at IZ = 5 mA with ±5% tolerance and exhibits 17 Ω dynamic impedance (ZZ) under that condition.
Thermal performance is defined by a maximum junction temperature of +150°C and storage range from –55°C to +150°C. Reverse leakage remains ≤0.25 µA at VR = 7.6 V, and forward conduction is limited to ≤0.9 V at IF = 10 mA - confirming suitability for bidirectional protection and dual-purpose biasing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 10.0 V ±5% at IZ = 5 mA - defines precise clamping threshold for 3.3 V/5 V rail monitoring and feedback loops. |
| Zener Impedance ZZ | 17 Ω @ IZ = 5 mA - ensures minimal voltage deviation under load transients in reference circuits. |
| Power Dissipation PD | 350 mW - sets maximum continuous DC power handling in SOT-23 without heatsinking. |
| Reverse Leakage IR | ≤0.25 µA @ VR = 7.6 V - guarantees negligible quiescent current draw in high-impedance sensing nodes. |
| Forward Voltage VF | ≤0.9 V @ IF = 10 mA - enables use as bidirectional ESD clamp or polarity-insensitive bias element. |
| Junction Temperature TJ | +150°C max - supports operation in industrial ambient environments with natural convection cooling. |
Pinout & Package
SOT-23 plastic surface-mount package with gull-wing leads; standard 3-pin configuration where Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Not Connected (NC). Compact 2.9 mm × 1.3 mm footprint enables high-density PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Connected to lower-potential node during reverse-bias regulation; forward conduction path when biased positive relative to cathode. |
| Pin 2 | Cathode | Connected to higher-potential node during Zener operation; defines regulated output reference point in shunt regulator topologies. |
| Pin 3 | NC | No internal connection - electrically isolated; must remain unconnected on PCB to avoid parasitic coupling or thermal stress. |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables accurate voltage setting without post-assembly trimming in production-grade analog references. |
| Low dynamic impedance (17 Ω) | Maintains tight regulation under varying load currents in feedback networks and sensor bias supplies. |
| Ultra-low reverse leakage (0.25 µA) | Preserves signal integrity in high-impedance measurement paths and battery-powered standby circuits. |
| SOT-23 footprint compatibility | Supports automated pick-and-place assembly and reflow soldering per IPC-7351 standards. |
Applications
| Industrial Sensor Signal Conditioning | USB Port Overvoltage Protection |
|---|---|
Use Scenario: Stabilizing excitation voltage for bridge-based pressure sensors in factory automation modules. IC Role / Device Role / Timing Role: Shunt Zener regulator providing fixed 10 V reference to ADC driver stage. Use Value: Maintains <±0.5% reference drift over –40°C to +85°C ambient due to low tempco and stable ZZ. | Use Scenario: Clamping transient surges on USB VBUS line during hot-plug events. IC Role / Device Role / Timing Role: Bidirectional transient voltage suppressor leveraging both Zener and forward conduction paths. Use Value: Limits peak excursion to ≤10.5 V while dissipating <350 mW during 100 ns ESD pulses per IEC 61000-4-2 Level 4. |
| Low-Power Microcontroller Reset Circuit | Programmable Logic Supply Rail Clamp |
Use Scenario: Generating clean reset pulse for ARM Cortex-M0+ MCU during brown-out conditions. IC Role / Device Role / Timing Role: Zener-based voltage monitor triggering external reset IC when supply drops below 9.5 V. Use Value: Delivers repeatable 10 V threshold with <1% hysteresis via resistor divider scaling, eliminating need for dedicated supervisor IC. | Use Scenario: Protecting FPGA I/O banks powered from 1.8 V or 2.5 V supplies against accidental 3.3 V misconnection. IC Role / Device Role / Timing Role: Clamp diode limiting input voltage to safe level using forward conduction path. Use Value: Activates at ≤0.9 V forward drop, preventing latch-up while drawing <10 mA at fault condition - compatible with IEC 61000-4-5 surge immunity testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C10 | Same 10 V ±5%, but 400 mW rating and 20 Ω ZZ @ 5 mA; slightly higher leakage (0.5 µA @ 7.6 V). | Higher power margin allows longer surge handling; less suitable for ultra-low-leakage sensor biasing. | Select BZX84-C10 when board-level surge energy exceeds 0.1 J and thermal mass permits higher PD. |
| MMBZ5240BLT1G | Identical electrical specs and SOT-23 package; RoHS-compliant variant with halogen-free molding compound. | No functional difference; intended for lead-free manufacturing and export-controlled regions. | Choose MMBZ5240BLT1G for compliance-driven designs requiring IPC-1752 reporting and REACH/SVHC declarations. |
Compared with BZX84-C10 and MMBZ5240BLT1G, the MMBZ5240B offers tighter leakage control and legacy qualification for cost-sensitive industrial revisions, while maintaining identical pinout and thermal profile - making it optimal for long-lifecycle embedded systems where consistency trumps regulatory updates.
Availability
MMBZ5240B is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB peripheral protection, microcontroller reset supervision, and FPGA I/O clamping requiring stable component supply across multi-year production cycles.
Supply support for MMBZ5240B 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.
The MMBZ52xxB series was developed for compact, high-reliability Zener regulation in portable and industrial electronics - emphasizing low leakage, stable impedance, and SOT-23 manufacturability.
FAQ
What is the exact Zener voltage tolerance for MMBZ5240B?
The MMBZ5240B has a nominal Zener voltage of 10.0 V with a tolerance of ±5% at IZ = 5 mA, meaning the actual measured VZ falls between 9.5 V and 10.5 V under standard test conditions. This tolerance is guaranteed across the full operating temperature range and is verified during wafer-level binning per Fairchild's Rev. A2 specification.
Can MMBZ5240B be used in bidirectional ESD protection?
Yes, the MMBZ5240B supports bidirectional protection because it conducts in forward bias (≤0.9 V @ 10 mA) and regulates in reverse bias (10 V Zener). Its symmetrical conduction characteristics allow implementation as a low-cost TVS pair in compact layouts - though dedicated ESD arrays offer lower capacitance for high-speed data lines.
What is the maximum allowable power dissipation for MMBZ5240B at 70°C ambient?
At 70°C ambient, the MMBZ5240B's power dissipation must be derated linearly from 350 mW at 25°C using its thermal resistance (RθJA ≈ 357°C/W). The maximum allowable PD is approximately 275 mW - calculated as 350 mW × [1 − (70 − 25)/357] - ensuring junction temperature stays below +150°C.
Is Pin 3 of MMBZ5240B internally connected?
No, Pin 3 of the MMBZ5240B is explicitly designated as "NC" (Not Connected) in the official Fairchild datasheet. It has no internal bond wire or die connection and must remain unconnected on the PCB. Routing traces to Pin 3 may introduce parasitic capacitance or thermal imbalance affecting regulation accuracy.
How does MMBZ5240B compare to MMBZ5240BLT1G?
The MMBZ5240B and MMBZ5240BLT1G share identical electrical specifications, SOT-23 package dimensions, and pinout. The "LT1G" suffix denotes RoHS-compliant, halogen-free packaging and lead-free terminations - required for export to EU/China markets but functionally interchangeable in non-regulated designs.
MMBZ5240B 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):
- 10 V
- Tolerance:
- ±5%
- Power - Max:
- 250 mW
- Impedance (Max) (Zzt):
- 17 Ohms
- Current - Reverse Leakage @ Vr:
- 3 µA @ 8 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
MMBZ5240B FAQ
1.How can I place an order for MMBZ5240B through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5240B 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 MMBZ5240B reliable?
The price and inventory of MMBZ5240B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5240B is usually 5 days.
3.What payment methods are accepted for MMBZ5240B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5240B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5240B?
MMBZ5240B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5240B 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 MMBZ5240B?
For technical support, including MMBZ5240B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5240B requirements.
6.How does Aetrix verify that MMBZ5240B is sourced from the original manufacturer or authorized distributors?
All MMBZ5240B 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 MMBZ5240B meets industry standards.
7.What is the process for return or replacement of MMBZ5240B?
All MMBZ5240B units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5240B, 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 MMBZ5240B part is unused and in its original packaging.
Return procedure for MMBZ5240B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5240B 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
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