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onsemi MMBZ5229ELT1
- Part No.:
- MMBZ5229ELT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5229ELT1.pdf
- Description:
- DIODE ZENER 4.3V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,860
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Product details
Overview
MMBZ5229ELT1 from onsemi is a 4.3 V nominal Zener voltage regulator diode in SOT-23 package, rated for 225 mW power dissipation at 25°C on FR-5 board, with 22 Ω maximum Zener impedance at 20 mA test current and 0.25 μA reverse leakage at 1 V reverse bias - used for precision voltage reference and overvoltage protection in space-constrained portable electronics.
For engineers reviewing the MMBZ5229ELT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, terminal roles, thermal derating behavior, ESD robustness (Class 3, >16 kV HBM), and direct alternatives for low-voltage regulation in battery-powered systems.
Technical Context
This device operates as a two-terminal voltage reference where reverse-biased breakdown provides stable regulation at 4.3 V ±0.22 V (min/max) under 20 mA test current. Its 22 Ω dynamic impedance at IZT ensures tight regulation under load transients, while 0.25 μA leakage at 1 V enables low-power standby operation.
The SOT-23 package features Pin 1 = Anode, Pin 2 = No Connection, Pin 3 = Cathode - confirmed by mechanical drawing Style 8 and Electrical Characteristics table. Thermal resistance is 556 °C/W on FR-5 board, requiring derating to 1.8 mW/°C above 25°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.08–4.52 V @ 20 mA - defines regulated output range for 3.3 V rail clamping or reference generation |
| Power Dissipation (PD) | 225 mW @ TA = 25°C on FR-5 - sets max continuous DC power before thermal shutdown risk |
| Zener Impedance (ZZT) | 22 Ω @ 20 mA - determines output voltage deviation under 1 mA load change (ΔV ≈ 22 mV) |
| Reverse Leakage (IR) | 0.25 μA @ 1 V - ensures negligible quiescent current in always-on voltage monitor circuits |
| ESD Rating | Class 3 (>16 kV HBM) - allows direct handling without special ESD controls during assembly |
| Thermal Resistance (RJA) | 556 °C/W on FR-5 - requires layout with ≥2 cm² copper pour to sustain full 225 mW at 70°C ambient |
| Junction Temp Range | −65°C to +150°C - supports operation in automotive under-hood or industrial outdoor enclosures |
Pinout & Package
SOT-23 (TO-236) surface-mount plastic package, 2.90 × 1.30 × 1.00 mm, void-free thermosetting case with corrosion-resistant finish; polarity band indicates cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node (e.g., GND or supply return); reverse bias applied between Pin 3 and Pin 1 |
| 2 | No Connection | Internally unconnected; no PCB trace or pad required - must remain floating per datasheet |
| 3 | Cathode | Connected to regulated voltage node (e.g., 3.3 V rail); breakdown occurs when cathode is ≥4.3 V above anode |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW Power Rating on FR-5 | Enables use in compact handheld devices without external heatsinking or airflow |
| ESD Robustness >16 kV HBM | Eliminates need for external TVS in low-energy signal line protection |
| Small SOT-23 Footprint | Reduces PCB area by 60% vs. DO-35, supporting ≥1000 components/in² board density |
| Pb-Free and RoHS Compliant | Meets IPC-J-STD-020 moisture sensitivity level 1 (MSL-1) for standard reflow |
| Peak Pulse Power 225 W | Withstands 8 × 20 µs surge events (e.g., IEC 61000-4-5 Level 3) without degradation |
Applications
| Battery Voltage Monitoring | USB Port Overvoltage Clamp |
|---|---|
|
Use Scenario: Detecting Li-ion cell under-voltage (<3.0 V) or over-voltage (>4.25 V) in portable power banks. IC Role / Device Role / Timing Role: Zener reference input to comparator or ADC reference divider network. Use Value: 4.3 V nominal VZ provides margin above 3.3 V logic rails while enabling accurate 4.2 V threshold detection via resistor scaling. |
Use Scenario: Preventing damage to USB 2.0 PHY ICs during hot-plug events with transient overshoot up to 5.5 V. IC Role / Device Role / Timing Role: Shunt clamp placed between VBUS and GND, conducting only above 4.3 V. Use Value: 22 Ω ZZT limits clamping voltage rise to <4.5 V at 100 mA surge, within USB 2.0 VBUS tolerance (5.5 V max). |
| Low-Power MCU Reset Circuit | Industrial Sensor Signal Conditioning |
|
Use Scenario: Generating clean reset pulse for ARM Cortex-M0 microcontrollers during brown-out conditions. IC Role / Device Role / Timing Role: Zener-based voltage detector feeding RC delay into reset pin. Use Value: 0.25 μA leakage at 1 V ensures <10 nA loading on high-impedance reset divider, preserving timing accuracy across temperature. |
Use Scenario: Stabilizing excitation voltage for 3.3 V bridge sensors in factory automation load cells. IC Role / Device Role / Timing Role: Precision shunt reference replacing bulkier TL431-based solutions. Use Value: 4.3 V VZ with ±5% tolerance (±0.22 V) achieves 0.5% full-scale sensor output stability without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C4V3 | Same 4.3 V nominal VZ, but 350 mW rating and 60 Ω ZZT; SOT-23 package with Pin 1 = Cathode, Pin 3 = Anode | Higher power handling suits higher-current clamping; higher ZZT reduces regulation precision | Select when surge energy exceeds 225 mW limits but layout allows polarity reversal |
| MMBZ5229BS | Same electrical specs, but in SOD-323 package (1.7 × 1.3 × 0.95 mm); no NC pin - Pin 1 = Anode, Pin 2 = Cathode | Smaller footprint saves 30% board area; lacks NC pin simplifies routing but removes mechanical redundancy | Select when ultra-high-density layout prohibits SOT-23 keepout or requires single-source footprint standardization |
Compared with MMBZ5229ELT1, BZX84-C4V3 offers higher surge capacity but looser regulation, while MMBZ5229BS reduces size at the cost of pinout compatibility - both require schematic and layout review due to differing pin assignments and thermal profiles.
Availability
MMBZ5229ELT1 is available at Aetrix Electronics and suitable for battery management systems, USB interface protection, MCU reset supervision, and industrial sensor excitation requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for MMBZ5229ELT1 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 is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications with focus on reliability and sustainability.
The MMBZ52xxELT1G series targets space-constrained, low-power voltage regulation in portable and high-density electronics - designed specifically for handheld devices, wearables, and miniaturized industrial modules.
FAQ
What is the exact Zener voltage tolerance of MMBZ5229ELT1 at 20 mA test current?
The MMBZ5229ELT1 has a guaranteed Zener voltage range of 4.08 V (minimum) to 4.52 V (maximum) at 20 mA test current and 25°C ambient, corresponding to a ±5% tolerance around the 4.3 V nominal value. This tolerance remains valid across the full −65°C to +150°C junction temperature range per datasheet Figure 7.
Does MMBZ5229ELT1 have a functional third pin, and what happens if Pin 2 is connected?
No, Pin 2 of the MMBZ5229ELT1 is internally not connected (NC) and must remain unconnected on the PCB. Connecting Pin 2 risks shorting internal die structures or altering thermal path integrity, potentially causing premature failure or parametric shift. The device functions correctly with only Pins 1 (Anode) and 3 (Cathode) soldered.
Can MMBZ5229ELT1 be used for bidirectional ESD protection like a TVS diode?
No, the MMBZ5229ELT1 is a unidirectional Zener diode optimized for reverse-bias voltage regulation only. It lacks symmetric breakdown characteristics and specified clamping performance in forward bias. For bidirectional ESD protection, dedicated TVS arrays such as ESD9X5.0ST5G (5 V bi-directional) must be used instead of MMBZ5229ELT1.
What is the maximum continuous reverse current MMBZ5229ELT1 can handle without exceeding its 225 mW rating?
At 25°C ambient, MMBZ5229ELT1 sustains up to 52.3 mA continuous reverse current (225 mW ÷ 4.3 V) before exceeding its power limit. However, due to thermal derating (1.8 mW/°C), this drops to ~35 mA at 70°C ambient. Designers must verify junction temperature using RJA = 556 °C/W and actual board copper area.
Is MMBZ5229ELT1 qualified for automotive applications, and what documentation confirms this?
The MMBZ5229ELT1 itself is not AEC-Q101 qualified; only the SZMMBZ5229ELT1G variant carries that qualification. The datasheet explicitly states "SZ Prefix for Automotive… AEC−Q101 Qualified", and MMBZ5229ELT1 appears only in the non-SZ ordering table. For automotive use, designers must specify SZMMBZ5229ELT1G - MMBZ5229ELT1 is intended for commercial/industrial applications only.
MMBZ5229ELT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 22 Ohms
- Current - Reverse Leakage @ Vr:
- 5 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:
- SOT-23-3 (TO-236)
MMBZ5229ELT1 FAQ
1.How can I place an order for MMBZ5229ELT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5229ELT1 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 MMBZ5229ELT1 reliable?
The price and inventory of MMBZ5229ELT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5229ELT1 is usually 5 days.
3.What payment methods are accepted for MMBZ5229ELT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5229ELT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5229ELT1?
MMBZ5229ELT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5229ELT1 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 MMBZ5229ELT1?
For technical support, including MMBZ5229ELT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5229ELT1 requirements.
6.How does Aetrix verify that MMBZ5229ELT1 is sourced from the original manufacturer or authorized distributors?
All MMBZ5229ELT1 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 MMBZ5229ELT1 meets industry standards.
7.What is the process for return or replacement of MMBZ5229ELT1?
All MMBZ5229ELT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5229ELT1, 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 MMBZ5229ELT1 part is unused and in its original packaging.
Return procedure for MMBZ5229ELT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5229ELT1 Tags
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