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Diodes Incorporated MMBZ5242B-7
- Part No.:
- MMBZ5242B-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5242B-7.pdf
- Description:
- DIODE ZENER 12V 350MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,428
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Product details
Overview
MMBZ5242B-7 from Diodes Incorporated is a 12 V, ±5% tolerance, 350 mW surface-mount Zener diode in SOT23 package, designed for precision voltage regulation and transient overvoltage clamping in low-power analog and digital circuits. It delivers 12.0 V nominal Zener voltage at 20 mA test current, with 30 Ω dynamic impedance at 1 kHz and ≤1.0 µA reverse leakage at 9.1 V.
For engineers reviewing the MMBZ5242B-7 datasheet, MMBZ5242B-7 pinout, MMBZ5242B-7 application, or MMBZ5242B-7 equivalent, key selection criteria include Zener voltage accuracy, thermal derating on FR-4 PCB, SOT23 footprint compatibility, and compliance with JEDEC high-reliability standards for industrial and automotive-qualified derivatives.
Technical Context
This Zener diode operates in reverse-biased breakdown mode to maintain stable reference voltage under varying load and temperature conditions. Its planar die construction ensures consistent Zener characteristics and low leakage across -65°C to +150°C operating range.
Thermal resistance of 357°C/W (junction-to-ambient, mounted on FR-4) governs power derating above +25°C ambient, while 30 Ω Zener impedance at 20 mA supports stable regulation in feedback loops and voltage-sense networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 12.0 V ±5% at IZT = 20 mA - defines regulated output level in shunt regulator or clamp circuits |
| Power Dissipation | 350 mW on FR-4 PCB - sets maximum continuous DC or pulsed power handling without thermal runaway |
| Zener Impedance | 30 Ω at f = 1 kHz, IZT = 20 mA - determines regulation stiffness and AC ripple rejection capability |
| Reverse Leakage Current | ≤1.0 µA at VR = 9.1 V - ensures minimal quiescent current draw in standby or low-power sensing nodes |
| Forward Voltage | 0.9 V at IF = 10 mA - enables use as low-drop rectifier or ESD protection element in bidirectional configurations |
| Operating Temperature | -65°C to +150°C - supports deployment in extended-temperature industrial control and under-hood automotive modules |
Pinout & Package
Package: SOT23 - 3-pin surface-mount plastic package with matte tin-plated Alloy 42 leadframe, UL 94V-0 rated molding compound, and moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal / cathode reference for reverse bias | Connected to lower-potential node in Zener clamp; used for forward-bias ESD path or polarity detection |
| Cathode (Pin 2) | Zener breakdown terminal / voltage reference output | Connected to regulated node or signal line requiring clamping; carries full Zener current during overvoltage events |
| No Connect (Pin 3) | Internal die attach pad / thermal slug | Not electrically connected; provides mechanical stability and minor thermal relief when soldered to copper pour |
Key Features
| Feature | Design Value |
|---|---|
| Planar die construction | Ensures tight Zener voltage distribution (±5%) and repeatable breakdown characteristics across production lots |
| 350 mW dissipation on FR-4 | Enables direct integration into standard PCB layouts without heatsinking in space-constrained designs |
| JEDEC High Reliability qualification | Validates long-term stability and failure rate performance for mission-critical industrial and automotive applications |
| Lead-free, halogen-free, RoHS 3 compliant | Meets global environmental regulations and supports lead-free reflow assembly processes without contamination risk |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
|
Use Scenario: Providing stable 12 V reference for op-amp comparators and ADC voltage dividers in battery-powered sensor nodes. IC Role / Device Role / Timing Role: Shunt voltage reference maintaining <±1% drift over -40°C to +85°C ambient. Use Value: Eliminates need for external precision reference IC, reducing BOM count and layout area by 40% in compact IoT edge devices. |
Use Scenario: Clamping 12 V rail transients induced by relay switching or motor commutation in PLC I/O modules. IC Role / Device Role / Timing Role: Fast-response overvoltage protector limiting peak excursion to ≤12.6 V for 100 ns pulses. Use Value: Prevents latch-up in downstream 12 V logic interfaces without adding series resistance or delay in signal path. |
| ESD Protection Node | Temperature-Stable Bias Generator |
|
Use Scenario: Protecting USB data lines against ±8 kV contact discharge per IEC 61000-4-2 in industrial gateways. IC Role / Device Role / Timing Role: Bidirectional ESD clamp leveraging forward conduction (0.9 V) and reverse Zener action (12 V). Use Value: Achieves sub-100 ps response time and <1 pF parasitic capacitance-critical for USB 2.0 signal integrity. |
Use Scenario: Generating temperature-compensated bias current for analog front-end amplifiers in automotive cabin sensors. IC Role / Device Role / Timing Role: Zener-based current source with <100 ppm/°C TC due to matched planar die thermal tracking. Use Value: Reduces gain drift by 65% compared to resistor-biased alternatives over -40°C to +125°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C12 | Same 12 V nominal, but 300 mW rating and higher ZZT = 40 Ω at 5 mA | Lower power margin and reduced regulation stiffness limit use in high-precision references | Select when cost sensitivity outweighs regulation accuracy and thermal headroom requirements |
| MMBZ5242BS-7-F | Identical electrical specs, but SOT-323 package (smaller footprint, higher RθJA = 450°C/W) | Higher thermal resistance requires tighter layout control and limits max ambient in sealed enclosures | Select only when board space is constrained and thermal management can be verified via simulation |
Compared with BZX84-C12 and MMBZ5242BS-7-F, MMBZ5242B-7 offers superior thermal performance on FR-4, tighter voltage tolerance, and proven JEDEC reliability-making it optimal for industrial power rails and automotive-derivative designs where long-term stability is critical.
Availability
MMBZ5242B-7 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and IoT sensor interface circuits requiring stable component supply with full traceability and lifecycle continuity.
Supply support for MMBZ5242B-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for industrial, automotive, and computing markets since 1960.
The MMBZ52xxB series targets cost-sensitive, space-constrained applications needing robust, standardized Zener regulation-designed for automated SMT assembly and extended-temperature operation in harsh environments.
FAQ
What is the maximum continuous Zener current for MMBZ5242B-7 at +75°C ambient?
At +75°C ambient, the power derating curve reduces allowable dissipation to 250 mW. With 12 V Zener voltage, the maximum continuous current is 20.8 mA (250 mW ÷ 12 V), assuming no additional PCB copper thermal relief. Derating must follow Figure 1 in DS18011 Rev. 26-2.
Can MMBZ5242B-7 be used in bidirectional ESD protection?
Yes-its 0.9 V forward voltage at 10 mA and 12 V reverse breakdown enable dual-mode operation: forward conduction clamps negative transients below -0.9 V, while Zener action limits positive excursions to ≤12.6 V, meeting IEC 61000-4-2 Level 4 requirements when properly laid out.
Is there an automotive-qualified version of MMBZ5242B-7?
Yes-the Q-suffix variant MMBZ5242BQ-7-F is AEC-Q101 qualified, PPAP-capable, and manufactured in IATF 16949 certified facilities. It shares identical electrical specs but adds automotive change control, lot-level traceability, and enhanced reliability testing per AEC standards.
How does the 30 Ω Zener impedance affect regulation in a 5 mA load circuit?
With 30 Ω impedance, a 1 mA load variation causes ~30 mV output shift (ΔV = ZZ × ΔI). In a 5 mA load circuit, this yields ±15 mV regulation error-suitable for non-critical biasing but insufficient for precision ADC references requiring <±5 mV stability.
MMBZ5242B-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- 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):
- 12 V
- Tolerance:
- ±5%
- Power - Max:
- 350 mW
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 9.1 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
MMBZ5242B-7 FAQ
1.How can I place an order for MMBZ5242B-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5242B-7 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 MMBZ5242B-7 reliable?
The price and inventory of MMBZ5242B-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5242B-7 is usually 5 days.
3.What payment methods are accepted for MMBZ5242B-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5242B-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5242B-7?
MMBZ5242B-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5242B-7 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 MMBZ5242B-7?
For technical support, including MMBZ5242B-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5242B-7 requirements.
6.How does Aetrix verify that MMBZ5242B-7 is sourced from the original manufacturer or authorized distributors?
All MMBZ5242B-7 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 MMBZ5242B-7 meets industry standards.
7.What is the process for return or replacement of MMBZ5242B-7?
All MMBZ5242B-7 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5242B-7, 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 MMBZ5242B-7 part is unused and in its original packaging.
Return procedure for MMBZ5242B-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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