My Inquiry
My Account
onsemi MMBZ5259BLT1G
- Part No.:
- MMBZ5259BLT1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5259BLT1G.pdf
- Description:
- DIODE ZENER 39V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:14,921
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MMBZ5259BLT1G from onsemi is a 39 V ±2.5% Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board, with 80 Ω dynamic impedance at 3.2 mA test current and 0.1 μA leakage at 30 V reverse bias. It provides precision voltage regulation in space-constrained portable electronics.
For engineers reviewing the MMBZ5259BLT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal resistance (556 °C/W), ESD rating (>16 kV HBM), cathode-anode polarity marking, and SOT-23 footprint compatibility with high-density PCB layouts.
Technical Context
This device operates as a two-terminal voltage reference using avalanche breakdown in silicon PN junction. Its nominal 39 V Zener voltage exhibits a positive temperature coefficient near +4.5 mV/°C, enabling stable regulation across −65°C to +150°C junction temperature range.
The SOT-23 package features a defined anode (Pin 1), no-connect (Pin 2), and cathode (Pin 3) configuration, with cathode polarity indicated by a band. Thermal performance is specified for both FR-5 board (225 mW @ 25°C) and alumina substrate (300 mW @ 25°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05 V min / 39 V nom / 40.95 V max @ IZT = 3.2 mA - defines regulated output voltage window under standard test conditions |
| Power Dissipation (PD) | 225 mW on FR-5 board @ 25°C - sets maximum continuous power handling before thermal derating begins |
| Zener Impedance (ZZT) | 80 Ω @ IZT = 3.2 mA - determines output voltage stability under varying load current |
| Leakage Current (IR) | 0.1 μA @ VR = 30 V - ensures minimal standby current draw in undervoltage protection circuits |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - supports robust handling in automated assembly without external protection |
| Junction Temperature Range | −65°C to +150°C - enables operation in automotive under-hood and industrial environments |
| Forward Voltage (VF) | 0.95 V max @ IF = 10 mA - confirms low-loss forward conduction for bidirectional clamping use cases |
Pinout & Package
SOT-23 (TO-236) surface-mount plastic package, 2.90 mm × 1.30 mm × 1.00 mm body size, void-free thermosetting case with corrosion-resistant finish, UL 94 V-0 flammability rating, and cathode polarity marked by band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Input terminal for reverse-bias operation; connects to lower-potential node in shunt regulator configuration |
| 2 | No Connection | Internally unconnected; must remain floating - no PCB trace or pad required |
| 3 | Cathode | Output terminal for reverse-bias operation; connects to regulated voltage rail and current-limiting resistor |
Key Features
| Feature | Design Value |
|---|---|
| Pb-Free, Halogen-Free/BFR-Free Construction | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-609A Class 1 moisture sensitivity |
| Small-Signal Zener Regulation | Enables compact voltage reference design in <1 mm² PCB area with 3.2 mA test current |
| High ESD Robustness | Eliminates need for external TVS diodes in handheld device ESD protection schemes |
| Thermal Performance on FR-5 | 556 °C/W junction-to-ambient resistance allows reliable operation up to 125°C ambient with proper layout |
| Automated Assembly Optimized | Transfer-molded case geometry and solderable finish support >99.9% placement yield in pick-and-place processes |
Applications
| Overvoltage Protection | Reference Voltage Source |
|---|---|
Use Scenario: Clamping transient surges on 3.3 V or 5 V I/O lines in smartphone baseband processors. IC Role / Device Role / Timing Role: Shunt regulator providing fast-response voltage limiting during ESD events. Use Value: 0.1 μA leakage at 30 V ensures negligible impact on standby current while clamping 39 V transients. |
Use Scenario: Generating stable 39 V reference for ADC biasing in battery-powered data loggers. IC Role / Device Role / Timing Role: Precision voltage reference with ±2.5% tolerance and +4.5 mV/°C TC. Use Value: 80 Ω Zener impedance maintains reference accuracy within 0.3% over 1–5 mA load variation. |
| Power Supply Monitoring | Signal Level Translation |
Use Scenario: Detecting brown-out conditions in 36–42 V industrial sensor modules. IC Role / Device Role / Timing Role: Threshold detector comparing supply voltage against 39 V Zener knee. Use Value: Sharp 3.2 mA test current knee enables reliable trip point detection with hysteresis via resistor divider. |
Use Scenario: Shifting logic levels between 3.3 V microcontroller GPIO and 39 V analog front-end circuitry. IC Role / Device Role / Timing Role: Bidirectional level translator using forward conduction (0.95 V) and reverse breakdown (39 V). Use Value: Dual-mode operation eliminates need for separate clamp and translation components in mixed-voltage interfaces. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C39LT1G | Same 39 V nominal Zener, but 350 mW rating on FR-4 and 60 Ω ZZT @ 5 mA - higher power and lower impedance | Preferred where higher surge energy absorption or tighter regulation under variable load is required | Select when board layout allows larger thermal mass or when 5 mA test current better matches system current budget |
| 1N4739A | Through-hole DO-41 package, 1 W rating, 9 Ω ZZT @ 19.5 mA - significantly higher power and lower impedance | Used in legacy designs or prototyping where manual assembly or high-power dissipation is acceptable | Choose only if SOT-23 footprint is not constrained and thermal management via heatsinking is feasible |
Compared with BZX84-C39LT1G and 1N4739A, MMBZ5259BLT1G offers optimal balance of ultra-small SOT-23 footprint, 225 mW FR-5 board rating, and 3.2 mA test current - making it ideal for modern portable electronics where board space and automated assembly are critical.
Availability
MMBZ5259BLT1G is available at Aetrix Electronics and suitable for cellular phones, handheld portables, and high-density PC boards requiring stable component supply and RoHS-compliant sourcing.
Supply support for MMBZ5259BLT1G 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 (Semiconductor Components Industries, LLC) is a global supplier of energy-efficient semiconductor solutions, specializing in automotive, industrial, cloud, medical, and IoT applications.
The MMBZ52xxBLT1G series was designed specifically for surface-mount voltage regulation in space-constrained portable electronics, emphasizing low-profile packaging, high ESD immunity, and tight Zener voltage tolerances.
FAQ
What is the Zener voltage tolerance of MMBZ5259BLT1G?
The MMBZ5259BLT1G has a Zener voltage tolerance of ±2.5% around its nominal 39 V value, meaning the actual measured voltage falls between 37.05 V and 40.95 V when tested at 3.2 mA. This tolerance is guaranteed across the full operating temperature range and is verified per onsemi's production test flow. The MMBZ5259BLT1G achieves this specification using tightly controlled diffusion and metallization processes in its SOT-23 silicon die.
Does MMBZ5259BLT1G have a no-connect pin, and how should it be handled on the PCB?
Yes, MMBZ5259BLT1G has Pin 2 designated as "No Connection" per the official onsemi mechanical drawing (Style 8). This terminal is internally unconnected and must remain electrically floating - no PCB trace, pad, or solder mask opening is required. Routing copper to Pin 2 may cause unintended parasitic coupling or assembly defects. The MMBZ5259BLT1G functions correctly with only Pins 1 (Anode) and 3 (Cathode) connected in the circuit.
What is the maximum power dissipation of MMBZ5259BLT1G on a standard FR-5 PCB?
The MMBZ5259BLT1G is rated for 225 mW total power dissipation on an FR-5 board at 25°C ambient temperature, with linear derating of 1.8 mW/°C above that point. This rating assumes standard JEDEC test conditions (1.0 × 0.75 × 0.62 inch board). Exceeding this limit risks thermal runaway or accelerated parametric drift. The MMBZ5259BLT1G's 556 °C/W junction-to-ambient thermal resistance directly supports this derating curve.
How does the ESD rating of MMBZ5259BLT1G compare to typical IC-level protection requirements?
The MMBZ5259BLT1G carries a Class 3 Human Body Model ESD rating exceeding 16 kV, which exceeds the IEC 61000-4-2 Level 4 requirement (8 kV contact / 15 kV air) for industrial equipment. This makes the MMBZ5259BLT1G suitable as a primary ESD clamp in handheld devices without supplemental protection. Its robustness stems from optimized junction geometry and passivation, and the MMBZ5259BLT1G maintains this rating across its full temperature range.
Can MMBZ5259BLT1G be used in bidirectional signal clamping applications?
Yes, the MMBZ5259BLT1G supports bidirectional clamping: its forward voltage is 0.95 V max at 10 mA, and its reverse Zener breakdown is 39 V nominal. This enables symmetric clamping of AC signals between −0.95 V and +39 V relative to ground. The MMBZ5259BLT1G's low forward drop and sharp reverse knee make it effective for protecting mixed-signal interfaces where both polarity excursions must be limited without adding discrete diodes.
MMBZ5259BLT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 30 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 (TO-236)
MMBZ5259BLT1G FAQ
1.How can I place an order for MMBZ5259BLT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5259BLT1G 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 MMBZ5259BLT1G reliable?
The price and inventory of MMBZ5259BLT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5259BLT1G is usually 5 days.
3.What payment methods are accepted for MMBZ5259BLT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5259BLT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5259BLT1G?
MMBZ5259BLT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5259BLT1G 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 MMBZ5259BLT1G?
For technical support, including MMBZ5259BLT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5259BLT1G requirements.
6.How does Aetrix verify that MMBZ5259BLT1G is sourced from the original manufacturer or authorized distributors?
All MMBZ5259BLT1G 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 MMBZ5259BLT1G meets industry standards.
7.What is the process for return or replacement of MMBZ5259BLT1G?
All MMBZ5259BLT1G units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5259BLT1G, 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 MMBZ5259BLT1G part is unused and in its original packaging.
Return procedure for MMBZ5259BLT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5259BLT1G 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…
