My Inquiry
My Account
onsemi MMBZ5221B
- Part No.:
- MMBZ5221B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5221B.pdf
- Description:
- DIODE ZENER 2.4V 350MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,503
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MMBZ5221B from Fairchild Semiconductor is a 2.4 V, ±5% tolerance Zener diode in SOT-23 package, rated for 350 mW power dissipation and 20 Ω dynamic impedance at 20 mA test current, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5221B datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage accuracy, low leakage (≤0.25 µA @ 1.0 V), stable temperature coefficient, and SOT-23 footprint compatibility with space-constrained PCB layouts.
Technical Context
The MMBZ5221B operates as a silicon planar Zener diode optimized for stable reverse-bias breakdown at 2.4 V nominal, with a 20 Ω zener impedance measured at 20 mA and 20 Ω knee impedance at 0.25 mA. Its forward voltage is ≤0.9 V at 10 mA, supporting bidirectional clamping in signal conditioning paths.
Designed for operation up to +150°C junction temperature and storage from –55°C to +150°C, the device maintains specified VZ stability across industrial temperature ranges, with typical VZ drift of ±0.05%/°C near room temperature per the family's 3.3 V and 5.1 V characterization curves.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 2.4 V ±5% - precise reference for low-voltage biasing and threshold detection |
| Power Dissipation (PD) | 350 mW - supports continuous regulation in compact SOT-23 without forced cooling |
| Zener Impedance (ZZ) | 30 Ω @ 20 mA - ensures minimal output voltage variation under load changes |
| Knee Impedance (ZZK) | 20 Ω @ 0.25 mA - enables stable regulation even at very low bias currents |
| Reverse Leakage (IR) | ≤0.25 µA @ 1.0 V - prevents signal path loading in high-impedance sensing nodes |
| Forward Voltage (VF) | ≤0.9 V @ 10 mA - allows use as bidirectional ESD clamp or polarity-insensitive shunt |
Pinout & Package
SOT-23 surface-mount package with 3 terminals; pin 1 = anode, pin 2 = cathode, pin 3 = no connection (NC). Compact 2.9 mm × 1.3 mm footprint enables high-density layout in portable and battery-powered systems.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node in reverse-bias regulation configuration |
| 2 | Cathode | Connected to regulated voltage rail; defines breakdown voltage reference point |
| 3 | NC | No internal connection; electrically isolated; must remain unconnected on PCB |
Key Features
| Feature | Design Value |
|---|---|
| ±5% VZ tolerance | Enables accurate voltage referencing without post-production trimming |
| Low IR at VR = 1.0 V | Minimizes quiescent current draw in always-on monitoring circuits |
| Stable TJ max = +150°C | Supports reliable operation in thermally demanding environments like automotive engine control modules |
| SOT-23 mechanical standardization | Ensures compatibility with automated pick-and-place equipment and reflow profiles |
Applications
| Portable Power Monitoring | USB Interface Protection |
|---|---|
Use Scenario: Monitoring battery voltage in wearables and IoT sensors where supply headroom is limited to <3.0 V. IC Role / Device Role / Timing Role: Zener reference for ADC input scaling and low-VCC brown-out detection circuitry. Use Value: 2.4 V breakdown enables direct interface with 2.5 V or 3.0 V microcontrollers without level-shifting. | Use Scenario: Clamping transient surges on USB D+ and D– lines during hot-plug events. IC Role / Device Role / Timing Role: Bidirectional ESD suppressor leveraging forward conduction (≤0.9 V) and reverse breakdown (2.4 V). Use Value: Low ZZK ensures fast response to sub-100 ns transients while maintaining signal integrity. |
| Industrial Sensor Signal Conditioning | Programmable Logic Supply Clamp |
Use Scenario: Stabilizing excitation voltage for resistive bridge sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Precision shunt regulator providing stable 2.4 V reference for Wheatstone bridge biasing. Use Value: ±5% VZ tolerance and low tempco reduce measurement error across –40°C to +85°C operating range. | Use Scenario: Protecting FPGA I/O banks powered by 2.5 V supplies against overvoltage faults. IC Role / Device Role / Timing Role: Active clamp limiting voltage excursion to ≤2.4 V during supply rail collapse or cross-coupling events. Use Value: 350 mW PD sustains short-duration fault energy without thermal runaway. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX79-C2V4 | Through-hole DO-35 package; 2.4 V ±5%; 500 mW rating; higher ZZ (60 Ω) | Requires PCB through-hole mounting; better suited for prototyping or high-reliability legacy designs | Select when manual assembly or higher power margin is required; not drop-in compatible with SOT-23 layout |
| MMBZ5221BS | SOT-23 variant with same electrical specs but RoHS-compliant matte tin lead finish | Identical performance; differs only in termination plating for lead-free soldering processes | Choose for new designs requiring RoHS compliance; fully interchangeable electrically and mechanically |
Compared with BZX79-C2V4 and MMBZ5221BS, the MMBZ5221B offers optimal SMT density and thermal performance for volume production, while MMBZ5221BS provides identical functionality with lead-free process compatibility.
Availability
MMBZ5221B is available at Aetrix Electronics and suitable for portable power monitoring, USB interface protection, and industrial sensor signal conditioning requiring stable component supply and consistent parametric performance across manufacturing lots.
Supply support for MMBZ5221B 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 MMBZ5221B belongs to the MMBZ52xxB Zener diode family designed for precision voltage reference and transient suppression in space-constrained, low-power electronic systems.
FAQ
What is the nominal zener voltage and tolerance of the MMBZ5221B?
The MMBZ5221B has a nominal zener voltage of 2.4 V with a tolerance of ±5% at 20 mA test current. This specification is verified per the Fairchild MMBZ5221B-MMBZ5257B datasheet Rev. A2 and applies under standard conditions of TA = 25°C. The MMBZ5221B maintains this voltage stability across its rated operating temperature range and power dissipation limit.
Does the MMBZ5221B have a no-connect pin, and how is it configured in SOT-23?
Yes, the MMBZ5221B uses a 3-pin SOT-23 package where pin 3 is explicitly designated as NC (no connection) in the official connection diagram. Pin 1 is the anode and pin 2 is the cathode; pin 3 must remain unconnected on the PCB. This configuration is confirmed in the Absolute Maximum Ratings section and Connection Diagram of the Fairchild MMBZ5221B-MMBZ5257B datasheet.
What is the maximum power dissipation rating for the MMBZ5221B?
The MMBZ5221B has a maximum power dissipation (PD) of 350 mW at TA = 25°C, as specified in the Absolute Maximum Ratings table. Derating is required above 25°C ambient, with linear reduction to zero at +150°C junction temperature. This rating enables reliable operation in compact SOT-23 layouts without heatsinking when used within its defined electrical limits.
How does the MMBZ5221B perform in forward bias, and what is its forward voltage specification?
The MMBZ5221B exhibits a maximum forward voltage (VF) of 0.9 V at 10 mA forward current, as stated in the datasheet's "VF Forward Voltage" note. This characteristic supports its use in bidirectional clamping applications, such as ESD protection on differential signal lines, where both forward conduction and reverse breakdown contribute to system robustness.
Is the MMBZ5221B suitable for automotive applications, and what temperature range does it support?
The MMBZ5221B supports an operating junction temperature range of –55°C to +150°C and storage from –55°C to +150°C, meeting requirements for under-hood and cabin electronics. While not AEC-Q200 qualified out-of-box, its thermal and electrical specifications align with many non-safety-critical automotive subsystems, including body control modules and sensor interfaces where external qualification is performed at the system level.
MMBZ5221B 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):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 350 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:
- SOT-23-3
MMBZ5221B FAQ
1.How can I place an order for MMBZ5221B through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5221B 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 MMBZ5221B reliable?
The price and inventory of MMBZ5221B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5221B is usually 5 days.
3.What payment methods are accepted for MMBZ5221B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5221B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5221B?
MMBZ5221B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5221B 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 MMBZ5221B?
For technical support, including MMBZ5221B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5221B requirements.
6.How does Aetrix verify that MMBZ5221B is sourced from the original manufacturer or authorized distributors?
All MMBZ5221B 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 MMBZ5221B meets industry standards.
7.What is the process for return or replacement of MMBZ5221B?
All MMBZ5221B units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5221B, 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 MMBZ5221B part is unused and in its original packaging.
Return procedure for MMBZ5221B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5221B 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
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
