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Diodes Incorporated MMBZ5238B-7
- Part No.:
- MMBZ5238B-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5238B-7.pdf
- Description:
- DIODE ZENER 8.7V 350MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,319
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Product details
Overview
MMBZ5238B-7 from Diodes Incorporated is an 8.7V, 350mW surface-mount Zener diode in SOT23 package, rated for 20mA test current with 8Ω dynamic impedance at 1kHz and 3µA reverse leakage at 6.5V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5238B-7 datasheet, MMBZ5238B-7 pinout, MMBZ5238B-7 application, or MMBZ5238B-7 equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (357°C/W on FR-4), JEDEC-compliant reliability, and compatibility with automated SMT assembly processes.
Technical Context
This Zener diode operates in reverse breakdown mode with a nominal Zener voltage of 8.7V at 20mA test current, maintaining regulation across a 8.27–9.14V range at TA = +25°C. Its 8Ω Zener impedance at 1kHz ensures stable reference performance under small-signal AC conditions.
Designed for low-power stabilization, it delivers 350mW dissipation on standard FR-4 PCBs with derating above +25°C per Fig. 1, and exhibits 3.0µA maximum reverse leakage at VR = 6.5V - critical for low-current bias networks and sensing front-ends.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.7V nominal, 8.27–9.14V min/max at IZT = 20mA - defines regulated output voltage window under standard test conditions |
| Zener Impedance (ZZT) | 8Ω at f = 1kHz, IZT = 20mA - determines AC regulation stiffness and noise rejection in reference circuits |
| Power Dissipation (PD) | 350mW on FR-4 PCB - sets absolute maximum continuous DC/average power handling in standard layout |
| Reverse Leakage (IR) | 3.0µA max at VR = 6.5V - limits error current in high-impedance bias or threshold detection nodes |
| Thermal Resistance (RθJA) | 357°C/W - quantifies junction-to-ambient temperature rise per watt, guiding thermal design on standard board |
| Operating Temperature | −65°C to +150°C - supports industrial and automotive under-hood environments without derating loss |
Pinout & Package
Package: SOT23 - 3-terminal surface-mount plastic package with matte tin-plated Alloy 42 leadframe, UL 94V-0 rated, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal / cathode reference ground path | Connected to circuit ground or lower potential node when used as shunt regulator |
| Cathode (Pin 2) | Zener breakdown terminal / regulated voltage output | Connected to input supply via series resistor; provides stable 8.7V reference at this node |
| No-Connect (Pin 3) | Internal die attach flag / mechanical support | Not electrically connected; serves structural role only - must remain unconnected in layout |
Key Features
| Feature | Design Value |
|---|---|
| Planar die construction | Enables tight VZ tolerance (±5%) and repeatable Zener characteristics across production lots |
| 350mW dissipation on FR-4 | Eliminates need for thermal vias or oversized copper in space-constrained consumer and IoT PCBs |
| Lead-free & RoHS 3 compliant | Meets global environmental compliance requirements without requiring process requalification |
| SOT23 footprint | Supports high-speed pick-and-place assembly and reflow soldering with industry-standard stencil profiles |
Applications
| Power Supply Monitoring | ADC Reference Clamp |
|---|---|
|
Use Scenario: Monitoring 12V rail in battery-powered instrumentation to trigger low-voltage warning before shutdown. IC Role / Device Role / Timing Role: Shunt regulator clamping reference voltage for comparator input. Use Value: 8.7V Zener provides precise trip point with <±0.2V variation over −40°C to +85°C, enabling reliable brown-out detection. |
Use Scenario: Protecting SAR ADC input from transient overvoltage during sensor signal conditioning. IC Role / Device Role / Timing Role: Input clamp limiting voltage to 8.7V ±5% to prevent ADC front-end damage. Use Value: 8Ω dynamic impedance ensures fast clamping response (<100ns) while limiting fault current to safe levels. |
| Microcontroller Reset Circuit | LED Current Regulation |
|
Use Scenario: Generating clean reset pulse for ARM Cortex-M0+ MCU during cold start of smart sensor node. IC Role / Device Role / Timing Role: Voltage reference in RC-based reset timing network. Use Value: Low 3.0µA leakage at 6.5V minimizes RC discharge error, ensuring consistent 100ms reset hold time across temperature. |
Use Scenario: Stabilizing forward voltage for blue LED string in portable display backlight. IC Role / Device Role / Timing Role: Parallel voltage reference setting constant-current source bias point. Use Value: Tight 8.27–9.14V VZ range maintains ±2% LED current accuracy despite supply ripple up to 500mVpp. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C8V2 (Nexperia) | 8.2V nominal, ±5% tolerance, 300mW rating, SOT23 package | Lower regulation voltage; higher ZZT (15Ω) reduces AC stability in precision references | Select when 8.2V threshold suffices and cost sensitivity outweighs impedance performance |
| MMBZ5237B-7 (Diodes Inc.) | 8.2V nominal, identical package, power, and leakage specs; 8Ω ZZT | Same thermal and assembly behavior but 0.5V lower regulation point for tighter margin designs | Choose for legacy 8.2V system compatibility where existing BOM uses MMBZ5237B-7 |
Compared with BZX84-C8V2 and MMBZ5237B-7, MMBZ5238B-7 offers the highest regulation voltage (8.7V) in its family with matched low impedance and thermal performance - optimal for systems requiring headroom above 8.2V while retaining SOT23 manufacturability.
Availability
MMBZ5238B-7 is available at Aetrix Electronics and suitable for power supply monitoring, ADC input protection, microcontroller reset circuits, and LED current regulation requiring stable component supply and full traceability.
Supply support for MMBZ5238B-7 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, specializing in high-reliability components for industrial, computing, and automotive markets.
This device belongs to the MMBZ52xxB Zener diode product line, engineered for precision voltage reference and overvoltage protection in space-constrained, high-volume SMT applications.
FAQ
What is the maximum reverse voltage (VR) at which MMBZ5238B-7 guarantees ≤3.0µA leakage?
The datasheet specifies 3.0µA maximum reverse leakage current at VR = 6.5V. This value is measured under controlled conditions at TA = +25°C and defines the upper limit of off-state conduction before breakdown onset - critical for low-power bias networks where leakage directly impacts quiescent current.
Can MMBZ5238B-7 be used in place of a 9.1V Zener like MMBZ5239B-7?
No - MMBZ5238B-7 has a nominal Zener voltage of 8.7V (8.27–9.14V range), while MMBZ5239B-7 is rated at 9.1V (8.65–9.56V). Substituting introduces a systematic 0.4V regulation error, exceeding typical design margins for precision references or clamps.
Is the SOT23 package of MMBZ5238B-7 compatible with standard IPC-7351B footprints?
Yes - Diodes' SOT23 outline matches IPC-7351B "SOT-23-3" generic footprint (body size 2.9×1.3mm, pin pitch 0.95mm). The recommended pad layout (X=0.8mm, Y=0.9mm, C=2.0mm) aligns with IPC Class L tolerances for reliable reflow yield.
Does MMBZ5238B-7 meet AEC-Q200 stress testing requirements for passive components?
No - MMBZ5238B-7 is not AEC-Q200 qualified. It is JEDEC-compliant and suitable for industrial use, but automotive applications require the Q-suffix variant (e.g., MMBZ5238BQ-7-F), which undergoes additional temperature cycling, humidity bias, and vibration testing per AEC-Q200 Rev D.
MMBZ5238B-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- 8.7 V
- Tolerance:
- ±5%
- Power - Max:
- 350 mW
- Impedance (Max) (Zzt):
- 8 Ohms
- Current - Reverse Leakage @ Vr:
- 3 µA @ 6.5 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
MMBZ5238B-7 FAQ
1.How can I place an order for MMBZ5238B-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5238B-7 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 MMBZ5238B-7 reliable?
The price and inventory of MMBZ5238B-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5238B-7 is usually 5 days.
3.What payment methods are accepted for MMBZ5238B-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5238B-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5238B-7?
MMBZ5238B-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5238B-7 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 MMBZ5238B-7?
For technical support, including MMBZ5238B-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5238B-7 requirements.
6.How does Aetrix verify that MMBZ5238B-7 is sourced from the original manufacturer or authorized distributors?
All MMBZ5238B-7 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 MMBZ5238B-7 meets industry standards.
7.What is the process for return or replacement of MMBZ5238B-7?
All MMBZ5238B-7 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5238B-7, 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 MMBZ5238B-7 part is unused and in its original packaging.
Return procedure for MMBZ5238B-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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