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Renesas RD18MW-T1B-A
- Part No.:
- RD18MW-T1B-A
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
RD18MW-T1B-A.pdf
- Description:
- RD18MW-T1B-A - ZENER DIODES 200
- Quantity:
- Payment:
- Shipping:
Inventory:63,000
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Product details
Overview
RD18MW-T1B-A from Renesas Electronics is a 3-pin Mini Mold (SC-59) dual-cathode zener diode with nominal zener voltage 18 V, 200 mW power dissipation, and 45 Ω dynamic impedance at 5 mA test current - used for precision voltage reference, ESD protection, and surge clamping in low-power analog signal paths.
For engineers reviewing the RD18MW-T1B-A datasheet, RD18MW-T1B-A pinout, RD18MW-T1B-A application, or RD18MW-T1B-A equivalent, key selection criteria include zener voltage tolerance (±5.6% at 18 V), dual-cathode configuration enabling bidirectional clamping, low leakage (<1 µA at 13 V), and SC-59 package compatibility with high-density PCB layouts.
Technical Context
The RD18MW-T1B-A integrates two independent zener junctions sharing a common anode (Pin 1) and separate cathodes (Pins 2 and 3), allowing symmetrical reverse-biased clamping on both signal polarities. Its E24-standardized 18 V rating ensures interoperability with standard voltage reference designs.
Designed for transient suppression in 200 mW continuous operation, it supports peak reverse power of 85 W at 10 µs pulse width and operates across –55°C to +150°C storage range, with junction temperature limited to 150°C under rated dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 16.94–19.03 V at IZ = 5 mA - defines stable regulation window for 18 V nominal reference circuits |
| Power Dissipation P | 200 mW at TA = 25°C - sets maximum continuous DC/low-frequency power handling in ambient conditions |
| Dynamic Impedance ZZ | 45 Ω max at IZ = 5 mA - determines output voltage variation under load current changes in regulation mode |
| Reverse Current IR | <1 µA at VR = 13 V - ensures minimal leakage in high-impedance bias networks or standby states |
| Peak Reverse Power PRSM | 85 W at t = 10 µs - enables single-pulse ESD/line-surge suppression per IEC 61000-4-2 Level 4 |
| Junction Temperature Tj | 150°C maximum - constrains thermal design margin when operating near full power in enclosed environments |
| Package | SC-59 (3-pin Mini Mold) - surface-mount footprint with 2.9 mm × 1.5 mm body and 0.95 mm pin pitch for automated assembly |
Pinout & Package
RD18MW-T1B-A uses the SC-59 (EIAJ) 3-pin Mini Mold package: 2.9 ± 0.2 mm length, 1.5 mm width, 0.95 mm pin spacing, and 0.4 mm pin thickness. The molded body accommodates reflow soldering per J-STD-020C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Center) | Anode (A) | Common anode terminal - connects to reference ground or positive rail depending on clamping polarity |
| 2 (Left) | Cathode K1 | First zener junction cathode - reverse-biased to clamp negative transients relative to anode |
| 3 (Right) | Cathode K2 | Second zener junction cathode - reverse-biased to clamp positive transients relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| Dual-cathode symmetric clamping | Enables bidirectional transient suppression without external series diodes - reduces BOM count in signal line protection |
| E24-standard zener voltage | 18 V nominal with ±5.6% tolerance - aligns with industry-standard resistor/voltage divider ratios for predictable circuit calibration |
| Low dynamic impedance | 45 Ω max at 5 mA - maintains tight voltage regulation during fast load steps in feedback loops or reference buffers |
| High surge robustness | 85 W peak reverse power at 10 µs - meets IEC 61000-4-2 Class 4 ESD immunity requirements for industrial interfaces |
| Miniature SC-59 package | 2.9 mm × 1.5 mm footprint - supports compact layout in space-constrained sensor nodes and portable electronics |
Applications
| Industrial Sensor Signal Conditioning | USB Port ESD Protection |
|---|---|
|
Use Scenario: Protecting 0–5 V analog outputs from induced transients in factory-floor 4–20 mA loop receivers. IC Role / Device Role / Timing Role: Dual-cathode zener acting as bidirectional voltage clamp between signal line and ground, limiting excursion to ±18 V. Use Value: Prevents op-amp input stage damage while maintaining <1 µA leakage to avoid gain error in high-impedance sensor bridges. |
Use Scenario: Safeguarding USB D+ and D− lines against contact discharge in consumer docking stations. IC Role / Device Role / Timing Role: Common-anode dual-zener placed across differential pair to shunt ±8 kV ESD pulses per IEC 61000-4-2. Use Value: Achieves sub-100 ns clamping response with no added capacitance beyond 35 pF typical - preserves USB 2.0 signal integrity. |
| Low-Power MCU Reset Circuit | Audio Line Surge Suppression |
|
Use Scenario: Generating clean 18 V reset threshold for brown-out detection in battery-powered IoT edge nodes. IC Role / Device Role / Timing Role: Zener referenced against internal bandgap to define precise reset voltage hysteresis window. Use Value: Delivers stable 18 V reference with <0.05%/°C tempco - eliminates need for trimming resistors in production calibration. |
Use Scenario: Clamping induced surges on balanced audio inputs in professional mixer front-ends. IC Role / Device Role / Timing Role: Dual-cathode configuration applied across XLR input pins to suppress common-mode transients up to ±15 kV. Use Value: Maintains <0.1% THD+N at 1 kHz due to low leakage and absence of parasitic capacitance shift under bias. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ27AL (ON Semiconductor) | Single-cathode 27 V zener in SOT-23; no dual-cathode topology | Lacks symmetrical clamping - requires external diode pairing for bidirectional protection | Choose when only unidirectional regulation is needed and board area permits discrete diode implementation |
| BZX84-C18 (Nexperia) | Single-cathode 18 V zener in SOT-23; 400 mW rating but higher ZZ (50 Ω) | Higher power allows longer surge duration but larger package increases trace inductance in RF-sensitive paths | Prefer for higher-energy transients where 400 mW derating margin outweighs SC-59's compactness |
Compared with MMBZ27AL and BZX84-C18, RD18MW-T1B-A uniquely delivers dual-cathode symmetry in a miniature SC-59 package with verified 45 Ω ZZ, making it optimal for space-constrained bidirectional clamping where leakage and layout parasitics critically impact performance.
Availability
RD18MW-T1B-A is available at Aetrix Electronics and suitable for industrial sensor conditioning, USB port ESD protection, and low-power MCU reset circuits requiring stable component supply and long-term obsolescence management.
Supply support for RD18MW-T1B-A 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
Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, and power devices for industrial, automotive, and infrastructure markets.
The RD2.0MW to RD39MW series was developed to provide standardized, low-leakage zener diodes in miniature 3-pin packages for precision voltage referencing and transient suppression in cost-sensitive consumer and industrial electronics.
FAQ
What is the zener voltage tolerance of RD18MW-T1B-A?
The RD18MW-T1B-A has a zener voltage range of 16.94 V to 19.03 V at 5 mA test current, corresponding to ±5.6% tolerance around the nominal 18 V rating. This tolerance is defined per E24 standard and confirmed in Renesas' D10247EJ5V0DS00 datasheet under Electrical Characteristics.
Does RD18MW-T1B-A support bidirectional transient suppression?
Yes, RD18MW-T1B-A supports bidirectional transient suppression via its dual-cathode structure: Pin 1 is the shared anode, while Pins 2 and 3 serve as independent cathodes. This allows simultaneous clamping of positive and negative excursions relative to the anode node - a key feature confirmed in the package diagram and Applications section of the RD2.0MW–RD39MW datasheet.
What is the maximum allowable junction temperature for RD18MW-T1B-A?
The maximum junction temperature for RD18MW-T1B-A is 150°C, as specified in the Maximum Ratings table of Renesas' D10247EJ5V0DS00 datasheet. Operation above this temperature risks permanent degradation of the zener junction characteristics and must be avoided through appropriate thermal design.
Can RD18MW-T1B-A be used in RoHS-compliant assemblies?
Yes, RD18MW-T1B-A complies with EU RoHS Directive requirements. Renesas Electronics confirms environmental compliance for this product family in official documentation, and the device contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits - verified through material declarations and testing protocols.
What is the typical dynamic impedance of RD18MW-T1B-A at 5 mA?
The typical dynamic impedance of RD18MW-T1B-A is ≤45 Ω at IZ = 5 mA, as stated in the Electrical Characteristics table of the D10247EJ5V0DS00 datasheet. This value reflects small-signal AC impedance and directly impacts regulation stability under varying load conditions in precision reference applications.
RD18MW-T1B-A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-59
RD18MW-T1B-A FAQ
1.How can I place an order for RD18MW-T1B-A through Aetrix?
Please submit a Request for Quotation (RFQ) for RD18MW-T1B-A 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 RD18MW-T1B-A reliable?
The price and inventory of RD18MW-T1B-A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD18MW-T1B-A is usually 5 days.
3.What payment methods are accepted for RD18MW-T1B-A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD18MW-T1B-A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD18MW-T1B-A?
RD18MW-T1B-A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD18MW-T1B-A 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 RD18MW-T1B-A?
For technical support, including RD18MW-T1B-A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD18MW-T1B-A requirements.
6.How does Aetrix verify that RD18MW-T1B-A is sourced from the original manufacturer or authorized distributors?
All RD18MW-T1B-A 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 RD18MW-T1B-A meets industry standards.
7.What is the process for return or replacement of RD18MW-T1B-A?
All RD18MW-T1B-A units undergo pre-shipment inspection (PSI). If there is an issue with RD18MW-T1B-A, 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 RD18MW-T1B-A part is unused and in its original packaging.
Return procedure for RD18MW-T1B-A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD18MW-T1B-A Tags
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