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Diodes Incorporated MMBZ5256BT-7-F
- Part No.:
- MMBZ5256BT-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- SOT-523
- Datasheet:
-
MMBZ5256BT-7-F.pdf
- Description:
- DIODE ZENER 30V 150MW SOT523
- Quantity:
- Payment:
- Shipping:
Inventory:4,801
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Product details
Overview
MMBZ5256BT-7-F from Diodes Incorporated is a 30 V, 150 mW surface-mount Zener diode in SOT-523 package, rated for 4.2 mA test current, 49 Ω dynamic impedance at 1 kHz, and 0.1 μA reverse leakage at 23 V, used for precision voltage regulation and overvoltage protection in space-constrained power management circuits.
For engineers reviewing the MMBZ5256BT-7-F datasheet, MMBZ5256BT-7-F pinout, MMBZ5256BT-7-F application, or MMBZ5256BT-7-F equivalent, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (833 °C/W), low capacitance (<2 pF), RoHS-compliant matte tin plating, and suitability for automated SMT assembly on FR-4 PCBs.
Technical Context
This device operates as a two-terminal voltage reference with sharp reverse breakdown at 30 V, leveraging planar die construction for stable Zener characteristics across -65 °C to +150 °C ambient range. Its low 150 mW power rating and high thermal resistance require careful derating above 25 °C per Figure 1.
Designed for general-purpose clamping and regulation, it delivers 49 Ω Zener impedance at 4.2 mA and maintains ≤0.1 μA leakage up to 23 V, enabling use in low-current biasing and signal-level voltage stabilization where minimal loading and predictable knee behavior are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 30 V ±5% - defines precise clamping threshold for 23–31.5 V regulation window |
| Power Dissipation | 150 mW - limits continuous DC or low-duty-cycle pulse operation on standard FR-4 pads |
| Zener Test Current | 4.2 mA - operating point at which voltage and impedance specs are guaranteed |
| Zener Impedance | 49 Ω @ 1 kHz - determines AC regulation accuracy and noise rejection in feedback paths |
| Reverse Leakage | 0.1 μA @ 23 V - ensures negligible standby current in high-impedance sensing or battery-backed circuits |
| Thermal Resistance | 833 °C/W - requires >50% power derating at 75 °C ambient per published curve |
| Package | SOT-523 - 1.6 mm × 0.8 mm footprint for ultra-dense PCB layouts |
Pinout & Package
SOT-523 is a three-terminal ultra-small plastic package with anode and cathode leads plus case ground (non-connected). Polarity is marked by a single band on the cathode end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Forward conduction terminal | Connected to lower-potential node during reverse-bias regulation |
| Cathode (K) | Zener breakdown terminal | Connected to higher-potential node; marking band identifies this pin |
| Case | Molded plastic body | Non-electrical; provides mechanical support and thermal path to PCB |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-small SOT-523 footprint | Enables placement in <1.0 mm² board area, ideal for wearables and miniaturized IoT sensors |
| Planar die construction | Delivers tight voltage tolerance and repeatable breakdown characteristics across production lots |
| Lead-free / RoHS-compliant plating | Matte tin finish over Alloy 42 leadframe ensures solderability and eliminates Pb-based process risks |
| Low 0.002 g weight | Reduces mechanical stress on fine-pitch solder joints during thermal cycling |
Applications
| USB Port ESD Clamp | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Protects USB D+ and D− lines from ±8 kV contact ESD per IEC 61000-4-2. IC Role / Device Role / Timing Role: Fast-acting shunt clamp that diverts surge current before IC input structures fail. Use Value: Sub-2 pF junction capacitance avoids signal integrity degradation at 480 Mbps USB 2.0 data rates. | Use Scenario: Generates clean, temperature-stable reset signal for ARM Cortex-M0+ MCUs during brown-out. IC Role / Device Role / Timing Role: Precision voltage reference setting threshold for external reset supervisor IC. Use Value: ±5% VZ tolerance and <0.1 μA leakage ensure reliable reset assertion down to 1.8 V supply rails. |
| Industrial Sensor Signal Conditioning | Low-Power Battery Monitor |
Use Scenario: Stabilizes excitation voltage for 4–20 mA loop-powered pressure transmitters. IC Role / Device Role / Timing Role: Low-drift voltage reference for op-amp biasing in analog front-end stages. Use Value: 49 Ω ZZT minimizes output impedance variation under load shifts, improving line regulation to ±0.5%. | Use Scenario: Detects end-of-life voltage drop in coin-cell–powered medical patches. IC Role / Device Role / Timing Role: Low-current Zener element in comparator reference leg for 2.8–3.0 V threshold detection. Use Value: 0.1 μA leakage at 23 V enables >10-year shelf life with CR2032 cells without measurable self-discharge impact. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C30LT1G | Same 30 V nominal, but SOD-523 package (slightly larger); 50 Ω ZZT; 0.1 μA IR | Higher thermal mass allows marginally better surge handling; identical regulation performance | Select when legacy SOD-523 tooling exists or higher surge immunity is prioritized |
| MMSZ5256ET1G | SOD-123 package; 30 V nominal; 50 Ω ZZT; 0.1 μA IR; 500 mW rating | Higher power dissipation supports higher-current bias networks but occupies 3× board area | Select when >150 mW continuous dissipation is required and space permits |
Compared with BZX584C30LT1G and MMSZ5256ET1G, MMBZ5256BT-7-F offers the smallest PCB footprint and lowest thermal resistance among 30 V Zeners in its class, making it optimal for ultra-compact, thermally constrained designs where 150 mW suffices.
Availability
MMBZ5256BT-7-F is available at Aetrix Electronics and suitable for USB interface protection, microcontroller reset generation, industrial sensor excitation, and low-power battery monitoring requiring stable component supply and full traceability.
Supply support for MMBZ5256BT-7-F 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
This part belongs to the MMBZ52xxBT series of miniature Zener diodes, engineered specifically for high-density, automated SMT applications demanding consistent voltage reference performance in consumer, computing, and industrial electronics.
FAQ
What is the maximum reverse voltage before breakdown for MMBZ5256BT-7-F?
The device exhibits sharp Zener breakdown at 30 V nominal, with guaranteed minimum and maximum values of 28.5 V and 31.5 V respectively at 4.2 mA test current. It remains in high-impedance reverse blocking mode below 23 V, where leakage stays ≤0.1 μA.
Can MMBZ5256BT-7-F be used in place of a 24 V Zener diode?
No - this is a 30 V device with a 28.5–31.5 V regulation band. Substituting it for a 24 V Zener would result in excessive voltage at the protected node and potential circuit malfunction. Use MMBZ5252BT-7-F (24 V) instead.
Is the SOT-523 package compatible with standard reflow profiles?
Yes - the device is qualified for lead-free reflow per J-STD-020D Level 1 moisture sensitivity, with peak temperatures up to 260 °C. Its matte tin plating ensures reliable wetting on OSP- and ENIG-finished PCBs using standard SAC305 profiles.
Does MMBZ5256BT-7-F have polarity markings on the package?
Yes - a single black band on the cathode end identifies the cathode terminal. The anode is unmarked. This matches the standard SOT-523 polarity convention and is verified in the Diodes Incorporated package outline drawing DS30267.
MMBZ5256BT-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOT-523
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 150 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 23 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-523
MMBZ5256BT-7-F FAQ
1.How can I place an order for MMBZ5256BT-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5256BT-7-F 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 MMBZ5256BT-7-F reliable?
The price and inventory of MMBZ5256BT-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5256BT-7-F is usually 5 days.
3.What payment methods are accepted for MMBZ5256BT-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5256BT-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5256BT-7-F?
MMBZ5256BT-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5256BT-7-F 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 MMBZ5256BT-7-F?
For technical support, including MMBZ5256BT-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5256BT-7-F requirements.
6.How does Aetrix verify that MMBZ5256BT-7-F is sourced from the original manufacturer or authorized distributors?
All MMBZ5256BT-7-F 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 MMBZ5256BT-7-F meets industry standards.
7.What is the process for return or replacement of MMBZ5256BT-7-F?
All MMBZ5256BT-7-F units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5256BT-7-F, 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 MMBZ5256BT-7-F part is unused and in its original packaging.
Return procedure for MMBZ5256BT-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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