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Diodes Incorporated DDZX18C-7
- Part No.:
- DDZX18C-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
DDZX18C-7.pdf
- Description:
- DIODE ZENER 18V 300MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,978
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Product details
Overview
DDZX18C-7 from Diodes Incorporated is a surface-mount precision Zener diode with nominal zener voltage 17.42–18.33 V at 10 mA test current, 23 Ω dynamic impedance at 10 mA, and 0.05 μA reverse leakage at 14.0 V. It delivers 300 mW power dissipation on FR-4 PCB and meets AEC-Q101 for automotive-grade reliability. Used in voltage reference and overvoltage protection circuits in industrial power supplies.
For engineers reviewing the DDZX18C-7 datasheet, DDZX18C-7 pinout, DDZX18C-7 application, or DDZX18C-7 equivalent, key selection criteria include zener voltage tolerance (±2.6%), temperature coefficient (~+0.07%/°C), low leakage at rated VR, SOT23 package compatibility, and AEC-Q101 qualification status.
Technical Context
This device operates as a two-terminal voltage reference with sharp breakdown characteristics and tightly controlled VZ tolerance. Its 23 Ω zener impedance at IZT = 10 mA ensures stable regulation under moderate load variation, while the 0.05 μA IR at VR = 14.0 V enables low-power standby sensing.
The SOT23 package supports automated assembly and provides thermal resistance of 417 °C/W to ambient on FR-4. It is rated for operation from –65 °C to +150 °C and qualified per AEC-Q101 for high-reliability automotive applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.42–18.33 V @ IZT = 10 mA - defines precise regulation point for feedback or clamping |
| Zener Impedance (ZZT) | 23 Ω @ IZT = 10 mA - ensures minimal output voltage shift under load current changes |
| Reverse Leakage (IR) | 0.05 μA @ VR = 14.0 V - enables ultra-low quiescent current in battery-backed reference circuits |
| Power Dissipation (PD) | 300 mW on FR-4 PCB - sets maximum continuous power handling without derating below 25°C |
| Thermal Resistance (RθJA) | 417 °C/W - determines junction temperature rise per mW dissipated in standard layout |
| Operating Temperature | –65 °C to +150 °C - supports extended-range industrial and under-hood automotive use |
| AEC-Q101 Qualified | Yes - confirms stress-tested reliability for automotive electronics per JEDEC standard |
Pinout & Package
Package: SOT23 - surface-mount plastic package with three terminals; leadframe finish is matte tin annealed over Alloy 42; moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal | Connected to lower potential side in reverse-biased Zener configuration |
| Cathode (Pin 2) | Zener breakdown terminal | Connected to higher potential side; carries regulated voltage during operation |
| No-Connect (Pin 3) | Internal die attach flag | Electrically isolated; used for mechanical anchoring and thermal path in SOT23 mold |
Key Features
| Feature | Design Value |
|---|---|
| Very tight VZ tolerance | ±2.6% (17.42–18.33 V range) - reduces need for post-production trimming in precision references |
| Low zener impedance | 23 Ω @ 10 mA - maintains regulation accuracy across ±2 mA load variation |
| Ultra-low leakage current | 0.05 μA @ 14.0 V - preserves battery life in always-on monitoring circuits |
| AEC-Q101 qualification | Qualified for automotive applications - eliminates requalification effort for Tier-1 designs |
| Lead-free & halogen-free | RoHS-compliant, <900 ppm Br/Cl, <1000 ppm Sb - satisfies global environmental compliance mandates |
Applications
| Industrial Power Supply Reference | Automotive ECU Voltage Clamp |
|---|---|
|
Use Scenario: Provides stable 18 V reference for feedback loop in isolated DC-DC converters operating from 24 V bus. IC Role / Device Role / Timing Role: Two-terminal shunt voltage reference regulating error amplifier input. Use Value: Tight VZ tolerance and low ZZT ensure ±0.5% output voltage stability across line/load/temperature. |
Use Scenario: Clamps transient overvoltage spikes on 12 V rail in engine control unit during load dump events. IC Role / Device Role / Timing Role: Passive overvoltage protection element absorbing surge energy above 14 V threshold. Use Value: AEC-Q101 qualification and 150 °C max TJ enable reliable operation in under-hood environments. |
| Medical Sensor Biasing | IoT Node Battery Monitor |
|
Use Scenario: Supplies precision bias voltage to analog front-end of portable blood oxygen sensor. IC Role / Device Role / Timing Role: Low-drift voltage reference for ADC reference input and op-amp biasing. Use Value: 0.05 μA IR minimizes drain on coin-cell battery during multi-week standby periods. |
Use Scenario: Monitors Li-ion cell voltage via resistive divider with Zener-stabilized reference. IC Role / Device Role / Timing Role: Stable reference source enabling ±1% state-of-charge estimation accuracy. Use Value: 23 Ω ZZT prevents reference droop when divider draws up to 100 μA during ADC sampling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18LT1G | VZ = 17.5–18.5 V @ 5 mA; ZZT = 45 Ω; no AEC-Q101 qualification | Limited to commercial-temperature industrial use; higher impedance affects regulation fidelity | Lower cost where automotive qualification and tight impedance are not required |
| MMSZ5245B-TP | VZ = 17.1–18.9 V @ 20 mA; ZZT = 35 Ω; 500 mW rating on FR-4 | Higher power rating but looser VZ tolerance (±5%) and no AEC-Q101 | Suitable for non-automotive designs needing higher surge energy absorption |
Compared with BZX84-C18LT1G and MMSZ5245B-TP, DDZX18C-7 offers superior voltage tolerance (±2.6% vs. ±5%), lower impedance (23 Ω vs. ≥35 Ω), and AEC-Q101 qualification-making it optimal for automotive and precision industrial references where regulation stability and reliability are critical.
Availability
DDZX18C-7 is available at Aetrix Electronics and suitable for industrial power supplies, automotive ECUs, medical sensor modules, and IoT battery monitors requiring stable component supply across long production lifecycles.
Supply support for DDZX18C-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, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
DDZX18C-7 belongs to the DDZX series of precision Zener diodes designed specifically for high-reliability voltage reference and clamping in automotive, industrial, and medical systems requiring AEC-Q101 compliance and tight parametric control.
FAQ
What is the maximum reverse voltage (VR) at which DDZX18C-7 guarantees IR ≤ 0.05 μA?
DDZX18C-7 guarantees reverse leakage current ≤ 0.05 μA at VR = 14.0 V, as specified in the Electrical Characteristics table. This value is measured under short-pulse conditions to minimize self-heating, and applies strictly at TA = +25°C unless otherwise noted.
Is DDZX18C-7 pin-compatible with standard SOT23 Zener diodes like BZX84-C18?
Yes, DDZX18C-7 uses the standard SOT23 footprint with anode (Pin 1), cathode (Pin 2), and no-connect (Pin 3). Its pin assignment matches JEDEC TO-236AB, enabling direct PCB replacement in layouts designed for BZX84-C18, provided thermal and electrical margins are verified.
Does DDZX18C-7 require derating above 25°C ambient temperature?
Yes - its power dissipation must be linearly derated above +25°C using the 417 °C/W RθJA value. For example, at +85°C ambient, maximum allowable PD drops to 177 mW (300 mW × [1 − (85−25)/417]). Derating follows the curve in Figure 1 of DS30408 Rev. 13-2.
How does the temperature coefficient of VZ behave for DDZX18C-7?
Based on Figure 17 in the datasheet, DDZX18C-7 exhibits a positive temperature coefficient of approximately +0.07%/°C near its nominal 18 V operating point. This means VZ increases by ~12.6 mV per °C rise in junction temperature, consistent with mid-voltage Zener devices.
DDZX18C-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:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±3%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 14 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
DDZX18C-7 FAQ
1.How can I place an order for DDZX18C-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for DDZX18C-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 DDZX18C-7 reliable?
The price and inventory of DDZX18C-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DDZX18C-7 is usually 5 days.
3.What payment methods are accepted for DDZX18C-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DDZX18C-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DDZX18C-7?
DDZX18C-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DDZX18C-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 DDZX18C-7?
For technical support, including DDZX18C-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DDZX18C-7 requirements.
6.How does Aetrix verify that DDZX18C-7 is sourced from the original manufacturer or authorized distributors?
All DDZX18C-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 DDZX18C-7 meets industry standards.
7.What is the process for return or replacement of DDZX18C-7?
All DDZX18C-7 units undergo pre-shipment inspection (PSI). If there is an issue with DDZX18C-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 DDZX18C-7 part is unused and in its original packaging.
Return procedure for DDZX18C-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
DDZX18C-7 Tags
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Diodes Incorporated
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Diodes Incorporated
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