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onsemi SZMMBZ5242BLT1
- Part No.:
- SZMMBZ5242BLT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SZMMBZ5242BLT1.pdf
- Description:
- DIODE ZENER 12V 225MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:8,878
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Product details
Overview
SZMMBZ5242BLT1 from onsemi is a 12 V ±5% Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board at 25°C, with 30 Ω maximum Zener impedance at 20 mA test current and 1 µA reverse leakage at 9.1 V. It serves as a precision voltage reference or overvoltage clamp in portable power rails and low-power sensor interfaces.
For engineers reviewing the SZMMBZ5242BLT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its AEC-Q101 qualification, Class 3 ESD rating (>16 kV HBM), Pb-free SOT-23 footprint, and tight 11.4–12.6 V Zener tolerance at IZT = 20 mA.
Technical Context
This device operates as a two-terminal voltage regulator using avalanche breakdown in silicon PN junction. Its nominal 12 V Zener voltage exhibits a positive temperature coefficient near zero crossing (~0.002%/°C typical), enabling stable reference performance across −65°C to +150°C junction range. The SOT-23 package features a cathode band (Pin 3) and non-connected Pin 2, supporting automated placement in high-density layouts.
Thermal resistance is 556°C/W (Junction-to-Ambient on FR-5), limiting continuous DC power to 225 mW at 25°C ambient with linear derating of 1.8 mW/°C above that point. Reverse leakage remains ≤1 µA at VR = 9.1 V, ensuring minimal quiescent current draw in battery-powered systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 11.4–12.6 V at IZT = 20 mA - defines regulated output voltage window under standard test conditions |
| Power Dissipation (PD) | 225 mW on FR-5 board @ 25°C - sets maximum steady-state power handling without heatsinking |
| Zener Impedance (ZZT) | ≤30 Ω @ IZT = 20 mA - determines regulation stiffness and AC ripple rejection capability |
| Reverse Leakage (IR) | ≤1 µA @ VR = 9.1 V - ensures low standby current in voltage-sense or clamping circuits |
| ESD Rating | Class 3 (>16 kV HBM) - supports robust handling in manual assembly and field-replaceable modules |
| Junction Temp Range | −65°C to +150°C - enables operation in automotive under-hood and industrial control environments |
| AEC-Q101 Qualified | Yes - validates reliability for automotive electronics per stress-test requirements |
Pinout & Package
SOT-23 (Case 318, Style 8) surface-mount package with void-free thermosetting plastic body, UL 94 V-0 flammability rating, and corrosion-resistant solderable finish. Cathode indicated by polarity band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node in reverse-bias configuration; carries forward current during fault conditions |
| 2 | No Connection | Internally unconnected; must remain floating - no PCB trace or pad required |
| 3 | Cathode | Connected to higher-potential node; defines regulated output voltage referenced to anode |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW Power Rating | Enables compact voltage regulation in space-constrained PCBs without external heat sinking |
| AEC-Q101 Qualification | Validates long-term reliability for automotive infotainment, ADAS sensors, and body control modules |
| Class 3 ESD Protection | Eliminates need for discrete ESD protection in front-end power monitoring circuits |
| Pb-Free Packaging | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 |
| Optimized SOT-23 Footprint | Supports 0.65 mm pitch pick-and-place and reflow profiles compatible with IPC-7095 standards |
Applications
| Automotive Sensor Power Rail | Portable Device Battery Monitor |
|---|---|
Use Scenario: Regulating 12 V supply for MEMS pressure sensor in engine control unit. IC Role / Device Role / Timing Role: Zener voltage reference providing stable bias for analog front-end amplifier. Use Value: Maintains <±1% output stability over −40°C to +125°C ambient with <30 Ω dynamic impedance. |
Use Scenario: Clamping ADC input during Li-ion battery voltage sampling in smartwatch. IC Role / Device Role / Timing Role: Overvoltage protector limiting sensed voltage to 12.6 V maximum. Use Value: Prevents ADC saturation with ≤1 µA leakage at 9.1 V, preserving battery life. |
| Industrial PLC I/O Module | Medical Wearable Signal Conditioning |
Use Scenario: Providing reference voltage for 4–20 mA loop transmitter calibration circuit. IC Role / Device Role / Timing Role: Precision shunt regulator establishing known voltage drop across sense resistor. Use Value: Achieves ±5% Zener tolerance and <0.5% TC drift over operating temperature range. |
Use Scenario: Stabilizing bias voltage for low-noise op-amp driving ECG electrode interface. IC Role / Device Role / Timing Role: Low-leakage voltage clamp protecting sensitive analog inputs. Use Value: Delivers <1 µA leakage at 9.1 V and Class 3 ESD immunity for patient-connected circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C12LT1G | Same 12 V nominal Zener, but 350 mW rating and 20 Ω ZZT; not AEC-Q101 qualified | Lacks automotive qualification; suitable for commercial-grade consumer electronics only | Select when higher power margin is needed and automotive compliance is unnecessary |
| MMSZ5242ET1G | 12 V Zener, 500 mW rating, 30 Ω ZZT, same SOT-23 package; AEC-Q101 qualified | Higher power rating allows use in higher-current regulation paths without thermal derating | Choose for designs requiring >225 mW continuous dissipation while retaining automotive qualification |
Compared with SZMMBZ5242BLT1, BZX84-C12LT1G offers higher power but no automotive qualification, while MMSZ5242ET1G provides identical Zener specs with doubled power rating and full AEC-Q101 compliance - making it preferable for thermally demanding automotive nodes.
Availability
SZMMBZ5242BLT1 is available at Aetrix Electronics and suitable for automotive sensor modules, portable medical devices, and industrial I/O systems requiring stable component supply with AEC-Q101 assurance and RoHS-compliant packaging.
Supply support for SZMMBZ5242BLT1 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
onsemi (Nasdaq: ON) is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.
SZMMBZ5242BLT1 belongs to the MMBZ52xxBLT1/SZMMBZ52xxBLT1G family of Zener regulators designed specifically for space-constrained, high-reliability voltage reference and clamping in automotive and portable electronics.
FAQ
What is the exact Zener voltage tolerance for SZMMBZ5242BLT1?
The SZMMBZ5242BLT1 has a guaranteed Zener voltage range of 11.4 V to 12.6 V at test current IZT = 20 mA and TA = 25°C. This ±5% tolerance is specified in the Electrical Characteristics table on page 3 of the official onsemi datasheet (Rev. 10, November 2011), and applies directly to the SZMMBZ5242BLT1 variant.
Is SZMMBZ5242BLT1 pin-compatible with MMBZ5242BLT1?
Yes - SZMMBZ5242BLT1 and MMBZ5242BLT1 share identical SOT-23 pinout (Pin 1: Anode, Pin 2: NC, Pin 3: Cathode), mechanical dimensions, and electrical specifications. The "SZ" prefix denotes automotive-grade qualification (AEC-Q101) and controlled change requirements, while "MM" indicates commercial grade; both use the same die and package.
What is the maximum continuous reverse current SZMMBZ5242BLT1 can sustain?
The SZMMBZ5242BLT1 is rated for 225 mW total power dissipation on FR-5 board at 25°C. At its nominal 12 V Zener voltage, this corresponds to a maximum continuous reverse current of 18.75 mA (225 mW ÷ 12 V). Derating applies above 25°C at 1.8 mW/°C, reducing usable current linearly with ambient temperature rise.
Does SZMMBZ5242BLT1 require a series current-limiting resistor in all applications?
Yes - like all Zener diodes, SZMMBZ5242BLT1 requires an external series resistor to limit reverse current to safe levels based on supply voltage and desired regulation point. For example, with a 15 V supply and target 20 mA Zener current, a 150 Ω resistor (R = (15 V − 12 V)/0.02 A) ensures operation within the 225 mW rating and maintains regulation stability.
How does the temperature coefficient of SZMMBZ5242BLT1 affect voltage stability?
SZMMBZ5242BLT1 exhibits a near-zero temperature coefficient around 12 V (approximately +0.002%/°C), meaning its Zener voltage changes less than 0.3 mV/°C over −65°C to +150°C. This low drift supports stable reference performance in automotive and industrial environments where ambient temperature varies widely - confirmed in Figure 1 of the onsemi datasheet.
SZMMBZ5242BLT1 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):
- 12 V
- Tolerance:
- ±5%
- Power - Max:
- 225 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:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
SZMMBZ5242BLT1 FAQ
1.How can I place an order for SZMMBZ5242BLT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMBZ5242BLT1 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 SZMMBZ5242BLT1 reliable?
The price and inventory of SZMMBZ5242BLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMBZ5242BLT1 is usually 5 days.
3.What payment methods are accepted for SZMMBZ5242BLT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMBZ5242BLT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMBZ5242BLT1?
SZMMBZ5242BLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMBZ5242BLT1 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 SZMMBZ5242BLT1?
For technical support, including SZMMBZ5242BLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMBZ5242BLT1 requirements.
6.How does Aetrix verify that SZMMBZ5242BLT1 is sourced from the original manufacturer or authorized distributors?
All SZMMBZ5242BLT1 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 SZMMBZ5242BLT1 meets industry standards.
7.What is the process for return or replacement of SZMMBZ5242BLT1?
All SZMMBZ5242BLT1 units undergo pre-shipment inspection (PSI). If there is an issue with SZMMBZ5242BLT1, 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 SZMMBZ5242BLT1 part is unused and in its original packaging.
Return procedure for SZMMBZ5242BLT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZMMBZ5242BLT1 Tags
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