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onsemi MMSZ5221BT1
- Part No.:
- MMSZ5221BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5221BT1.pdf
- Description:
- DIODE ZENER 2.4V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:9,227
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Product details
Overview
MMSZ5221BT1 from ON Semiconductor is a 2.4 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation on FR−5 board at 75°C, with 1200 Ω maximum dynamic impedance at 20 mA test current and 0.25 µA leakage current at 100 V reverse bias-used for precision voltage reference and overvoltage protection in low-power sensor interfaces and microcontroller reset circuits.
For engineers reviewing the MMSZ5221BT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, cathode/anode terminal mapping, automotive-grade AEC−Q101 qualification status, and direct alternatives for voltage regulation in space-constrained PCB designs.
Technical Context
This device operates as a silicon planar Zener diode optimized for stable reverse-bias voltage regulation under thermal equilibrium conditions (TL = 30°C ±1°C), with nominal Zener voltage specified at IZT = 20 mA and VF ≤ 0.95 V at IF = 10 mA. Its 150 °C/W junction-to-lead thermal resistance enables reliable operation in thermally constrained layouts.
The MMSZ5221BT1 exhibits a temperature coefficient of −3.5 mV/°C near 2.4 V (per Figure 1), confirming negative TC behavior typical of low-voltage Zeners, and supports ESD robustness to >16 kV per Human Body Model-critical for handling-sensitive industrial control modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 2.4 V nominal, 2.28–2.52 V range at IZT = 20 mA - defines precise clamping threshold for 3.3 V rail monitoring. |
| Power Dissipation (PD) | 500 mW on FR−5 board at TL = 75°C - sets maximum continuous power before thermal derating begins. |
| Zener Impedance (ZZT) | 1200 Ω max at IZT = 20 mA - indicates voltage regulation stability under small-signal AC load variations. |
| Leakage Current (IR) | 0.25 µA max at VR = 100 V - ensures minimal standby current draw in battery-powered wake-up circuits. |
| Junction Temp Range | −55°C to +150°C - supports operation in automotive engine compartments and industrial motor drives. |
| ESD Rating | Class 3 (>16 kV HBM) - eliminates need for external ESD protection in handheld diagnostic tools. |
| Tolerance | ±5% - suitable for non-critical biasing where cost-sensitive design tolerates moderate voltage variation. |
Pinout & Package
SOD−123 surface-mount plastic package (Case 425, Style 1), void-free transfer-molded thermosetting construction with corrosion-resistant, solderable finish; polarity band denotes cathode; UL 94 V−0 flammability rating; 260°C max soldering temperature for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated output node; reverse-biased during Zener conduction; requires proper PCB trace width for thermal relief. |
| 2 (Non-banded End) | Anode | Connected to ground or lower-potential rail; serves as reference return path; must maintain low-impedance connection to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC−Q101 qualified and PPAP capable - enables use in ASIL-B compliant power management subsystems without requalification. |
| Pb−Free construction | RoHS-compliant SOD−123 package - meets global environmental compliance requirements for consumer and medical electronics. |
| Thermal equilibrium spec | Zener voltage measured at TL = 30°C ±1°C - guarantees accuracy under stabilized board-level thermal conditions, not ambient-only testing. |
| High-density footprint | Small outline (2.84 mm × 1.35 mm × 1.17 mm) - allows placement adjacent to BGA packages or within tight spacing constraints of wearable sensor modules. |
| Medium-current capability | Rated for up to 20 mA Zener current - balances regulation precision with low-power consumption in IoT edge nodes. |
Applications
| Microcontroller Reset Circuit | Low-Power Sensor Biasing |
|---|---|
Use Scenario: Generating a clean, temperature-stable reset signal for ARM Cortex-M0+ MCUs operating from 3.3 V supply. IC Role / Device Role / Timing Role: Zener diode provides accurate 2.4 V threshold to trigger external reset supervisor IC when supply drops below safe operating level. Use Value: Tight ±5% tolerance and −3.5 mV/°C TC ensure reset assertion remains within 2.3–2.5 V across −40°C to +85°C industrial temperature range. | Use Scenario: Establishing stable bias voltage for analog front-end amplifiers in battery-powered gas sensors. IC Role / Device Role / Timing Role: Functions as passive voltage reference for op-amp input stage, replacing higher-cost precision references where 2.4 V suffices. Use Value: 0.25 µA leakage at 100 V ensures <1 nA error contribution to picoampere-level sensor current measurements. |
| USB Port Overvoltage Clamp | Industrial PLC Input Protection |
Use Scenario: Protecting 3.3 V USB data line receivers from transient surges exceeding 5.5 V. IC Role / Device Role / Timing Role: Acts as fast-acting shunt clamp, diverting surge energy to ground before receiver IC damage occurs. Use Value: 500 mW rating and 1200 Ω ZZT enable effective clamping of 100 ns transients without thermal runaway in compact USB-C connector assemblies. | Use Scenario: Safeguarding 24 V digital input channels in programmable logic controllers against field-wiring faults. IC Role / Device Role / Timing Role: Provides secondary overvoltage protection downstream of TVS diodes, absorbing residual energy after primary suppression. Use Value: −55°C to +150°C junction range ensures reliability in unventilated control cabinets exposed to ambient extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C2V4LT1G | Same 2.4 V ±5% Zener voltage, but rated for only 300 mW and uses SOT-23 package. | Lower power rating limits use in sustained-clamp scenarios; larger SOT-23 footprint reduces board density. | Select when existing layout uses SOT-23 and thermal load stays below 300 mW. |
| MMSZ4678T1G | 2.4 V Zener but with ±2% tolerance and 1000 Ω ZZT, same SOD−123 package. | Higher precision and lower impedance suit feedback loops requiring tighter regulation, at modest cost premium. | Choose for closed-loop voltage monitor circuits where 2% tolerance improves ADC reference accuracy. |
Compared with MMSZ5221BT1, BZX84-C2V4LT1G offers smaller thermal mass but reduced power handling, while MMSZ4678T1G delivers tighter tolerance and lower impedance at identical footprint-making it preferable for precision analog sensing where cost permits.
Availability
MMSZ5221BT1 is available at Aetrix Electronics and suitable for microcontroller reset circuits, low-power sensor biasing, USB port overvoltage clamping, and industrial PLC input protection requiring stable component supply across automotive, industrial, and medical product lifecycles.
Supply support for MMSZ5221BT1 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
ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The MMSZ52xxxT1G series was designed specifically for high-reliability, space-constrained voltage regulation in automotive ECUs and industrial control systems-emphasizing AEC−Q101 qualification, Pb−free compliance, and thermal equilibrium performance validation.
FAQ
What is the exact Zener voltage tolerance for MMSZ5221BT1?
The MMSZ5221BT1 has a guaranteed Zener voltage tolerance of ±5% at IZT = 20 mA and thermal equilibrium (TL = 30°C ±1°C), with minimum/maximum values of 2.28 V and 2.52 V respectively. This tolerance is confirmed in Table 3 of the official ON Semiconductor datasheet MMSZ5221BT1/D, and applies specifically to the "B" suffix variant in the MMSZ52xxxT1G family.
Is MMSZ5221BT1 qualified for automotive applications?
Yes, MMSZ5221BT1 is AEC−Q101 qualified and PPAP capable, as explicitly stated in the "Features" section of its datasheet. It meets automotive reliability standards including high-temperature operation up to +150°C junction temperature and Class 3 ESD robustness (>16 kV HBM), making it suitable for under-hood and body-control module applications.
What is the maximum allowable power dissipation for MMSZ5221BT1 at 100°C ambient?
At 100°C ambient, MMSZ5221BT1 must be derated from its 500 mW rating using the 6.7 mW/°C slope above 75°C. Derating starts at 75°C, so over 25°C above that point, power drops by 167.5 mW (25 × 6.7), yielding a maximum safe dissipation of 332.5 mW. This value assumes FR−5 board mounting with minimum recommended footprint per datasheet Note 1.
Does MMSZ5221BT1 have a defined temperature coefficient, and what is its value?
Yes, MMSZ5221BT1 has a documented temperature coefficient of approximately −3.5 mV/°C near its 2.4 V Zener voltage, as shown in Figure 1 ("Typical TC Values for MMSZ52xxBT1G Series") of the datasheet. This negative coefficient means its Zener voltage decreases slightly with rising temperature-a key factor when designing across wide ambient ranges.
Can MMSZ5221BT1 replace MMSZ5221BT1G in a production design?
No-MMSZ5221BT1 and MMSZ5221BT1G are distinct orderable parts. The "G" suffix denotes Pb−free packaging and RoHS compliance, while MMSZ5221BT1 (without G) is an obsolete or non-Pb−free variant. ON Semiconductor's ordering information confirms only MMSZ5221BT1G and SZMMSZ5221BT1G are active Pb−free part numbers; MMSZ5221BT1 should not be used in new designs.
MMSZ5221BT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 100 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
MMSZ5221BT1 FAQ
1.How can I place an order for MMSZ5221BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5221BT1 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 MMSZ5221BT1 reliable?
The price and inventory of MMSZ5221BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5221BT1 is usually 5 days.
3.What payment methods are accepted for MMSZ5221BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5221BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5221BT1?
MMSZ5221BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5221BT1 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 MMSZ5221BT1?
For technical support, including MMSZ5221BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5221BT1 requirements.
6.How does Aetrix verify that MMSZ5221BT1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5221BT1 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 MMSZ5221BT1 meets industry standards.
7.What is the process for return or replacement of MMSZ5221BT1?
All MMSZ5221BT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5221BT1, 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 MMSZ5221BT1 part is unused and in its original packaging.
Return procedure for MMSZ5221BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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