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Renesas RD18ES-T1
- Part No.:
- RD18ES-T1
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD18ES-T1.pdf
- Description:
- DIODE ZENER
- Quantity:
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Inventory:6,888
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Product details
Overview
RD18ES-T1 from Renesas Electronics is a 18 V, 400 mW DO-34 glass-sealed zener diode with DHD (Double Heatsink Diode) construction, ±5% zener voltage tolerance at 13 mA test current, 30 Ω dynamic impedance, and 0.2 µA reverse leakage at 14.4 V, used for precision voltage regulation in power supply reference circuits.
For engineers reviewing the RD18ES-T1 datasheet, RD18ES-T1 pinout, RD18ES-T1 application, or RD18ES-T1 equivalent, this page delivers verified electrical specs, thermal performance data, JEDEC DO-34 package details, and real-world use cases for constant-voltage clamping and overvoltage protection in industrial control and consumer power supplies.
Technical Context
The RD18ES-T1 operates as a two-terminal silicon planar zener diode optimized for stable reverse-bias breakdown at 18 V nominal. Its DHD construction enables enhanced thermal dissipation in the compact DO-34 package, supporting continuous 400 mW power handling at 25°C ambient and derated operation up to 175°C junction temperature.
It exhibits a positive zener voltage temperature coefficient (~+0.06 %/°C per Fig. 9), low knee impedance (150 Ω at 0.5 mA), and robust surge capability (100 W for 10 µs pulses), making it suitable for transient suppression and precision biasing where tight voltage stability and repeatable breakdown behavior are required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 16.34–18.30 V at IZ = 13 mA; ensures stable regulation within ±5% tolerance across production units |
| Power Dissipation (P) | 400 mW at TA = 25°C; defines maximum steady-state thermal load before derating begins |
| Dynamic Impedance (ZZ) | 30 Ω at IZ = 13 mA; determines output voltage variation under load current changes |
| Reverse Leakage (IR) | 0.2 µA max at VR = 14.4 V; guarantees minimal standby current in high-impedance reference nodes |
| Junction Temperature (Tj) | 175°C max; sets upper thermal limit for reliable long-term operation in enclosed environments |
| Surge Power (PRSM) | 100 W for t = 10 µs; supports single-event transient suppression without failure |
| Package | DO-34 (JEDEC); 2.4 mm max body length, 5 mm lead pitch - enables high-density through-hole PCB layout |
Pinout & Package
RD18ES-T1 is a two-terminal axial-leaded device in the DO-34 glass package. Cathode is marked by a black band on the body. No internal circuitry or active control logic - terminals serve only as anode and cathode for unidirectional zener operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node; reverse-biased during regulation to establish fixed VZ drop |
| Cathode | Zener breakdown terminal / Voltage reference output | Marked with black band; provides stable 18 V reference when biased above VZ with current-limiting resistor |
Key Features
| Feature | Design Value |
|---|---|
| DHD (Double Heatsink Diode) construction | Enables 400 mW dissipation in DO-34 by improving heat transfer from die to both leads and glass envelope |
| Planar process technology | Delivers tight VZ distribution (±5%) and low parametric drift over time and temperature |
| E24 standard zener voltage grading | Ensures compatibility with common resistor/capacitor value series for predictable reference design |
| DO-34 glass seal | Provides hermetic reliability and moisture resistance for long-term stability in humid environments |
| Short 5 mm lead pitch | Supports dense PCB layouts without requiring lead forming or spacing adjustments |
Applications
| Industrial Power Supply Reference | Overvoltage Clamp in DC-DC Converters |
|---|---|
Use Scenario: Providing stable 18 V reference for feedback loops in isolated AC/DC adapters and programmable bench supplies. IC Role / Device Role / Timing Role: Passive voltage reference element - establishes precise error amplifier setpoint independent of input ripple or load transients. Use Value: Maintains ±1% output regulation accuracy over 0–70°C ambient due to low ZZ and predictable TC characteristics. | Use Scenario: Clamping gate drive voltage spikes on MOSFETs in synchronous buck converters operating at 12–24 V input. IC Role / Device Role / Timing Role: Transient voltage suppressor - shunts excess energy during switching edge overshoot to protect driver IC inputs. Use Value: Absorbs 100 W surges (10 µs) without degradation, preventing latch-up or gate oxide damage in power stages. |
| Audio Equipment Bias Network | Surge Protection in Sensor Signal Conditioning |
Use Scenario: Generating clean, low-noise bias voltages for op-amp rails and transistor amplifiers in studio-grade audio mixers. IC Role / Device Role / Timing Role: Low-current voltage reference - supplies stable 18 V to high-impedance bias networks with sub-µA leakage impact. Use Value: Delivers <0.5 µV RMS noise and <0.2 µA IR at 14.4 V, preserving signal integrity in analog front-ends. | Use Scenario: Protecting 18 V rail-connected analog sensors (e.g., pressure transducers) from ESD and lightning-induced transients. IC Role / Device Role / Timing Role: Primary clamping element - limits rail voltage excursions to ≤18.3 V during fast-rising surges. Use Value: Responds within nanoseconds and withstands repeated 100 W pulses, extending sensor module field life in harsh industrial settings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | 18 V nominal, 1 W rating, DO-41 package, 25 Ω ZZ, 100 µA IR at 14.4 V | Higher power, larger footprint, higher leakage - suited for higher-current references but less space-efficient | Select when >400 mW continuous dissipation is needed and board area allows DO-41 placement |
| BZX55-C18 | 18 V nominal, 500 mW rating, DO-35 package, 35 Ω ZZ, 0.1 µA IR at 14.4 V | Smaller DO-35 body, tighter leakage spec, slightly higher ZZ - better for ultra-low-power biasing | Select when minimizing leakage dominates over thermal margin, and DO-35 mechanical fit is acceptable |
Compared with RD18ES-T1, 1N4746A offers higher power headroom but requires more PCB area and exhibits higher reverse leakage, while BZX55-C18 provides superior leakage performance in a smaller package but with marginally higher dynamic impedance - choice depends on thermal, space, and leakage trade-offs in the target design.
Availability
RD18ES-T1 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface modules, and audio equipment requiring stable component supply with consistent zener voltage tolerance and thermal reliability.
Supply support for RD18ES-T1 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 global semiconductor leader delivering microcontrollers, analog, power, and timing solutions for automotive, industrial, and consumer applications.
RD18ES-T1 belongs to the legacy NEC RD-series zener diodes, designed for general-purpose voltage regulation and transient suppression in cost-sensitive, high-reliability industrial and consumer electronics.
FAQ
What is the exact zener voltage range for RD18ES-T1 at 13 mA test current?
The RD18ES-T1 has a guaranteed zener voltage range of 16.34 V to 18.30 V when tested at IZ = 13 mA and TA = 25°C, corresponding to a ±5% tolerance about the nominal 18 V rating. This range is confirmed in the official Renesas datasheet D13935EJ7V0DS, Table on page 3 for RD18ES with suffix AB1/AB2/AB3 variants.
Does RD18ES-T1 have a specified zener voltage temperature coefficient?
Yes, RD18ES-T1 exhibits a positive temperature coefficient of approximately +0.06 %/°C, as shown in Figure 9 of the Renesas datasheet D13935EJ7V0DS. This means its zener voltage increases by ~10.8 mV per °C rise in junction temperature, enabling predictable compensation in temperature-sensitive reference designs.
What is the maximum allowable surge power for RD18ES-T1 and under what conditions?
RD18ES-T1 supports a non-repetitive surge reverse power of 100 W for pulse width t = 10 µs, as specified in the Absolute Maximum Ratings table and illustrated in Figure 10 of the Renesas datasheet. This rating assumes single-event application and proper PCB thermal relief; repetitive surges require derating per thermal impedance curves in Figure 11.
Is RD18ES-T1 compliant with RoHS and lead-free assembly requirements?
RD18ES-T1 is manufactured to RoHS-compliant specifications per Renesas' environmental policy, with lead-free terminations compatible with standard SnAgCu reflow profiles. The DO-34 glass package contains no restricted substances above EU RoHS thresholds, and full compliance documentation is available upon request from Renesas Electronics.
Can RD18ES-T1 be used in place of RD18ES without the "-T1" suffix?
Yes - RD18ES-T1 is the tape-and-reel packaging variant of the same die and electrical specification as RD18ES. Both share identical zener voltage, dynamic impedance, thermal ratings, and DO-34 package dimensions; the "-T1" suffix denotes automated pick-and-place compatibility, not functional differentiation. RD18ES-T1 is fully interchangeable with RD18ES in all electrical and thermal contexts.
RD18ES-T1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
RD18ES-T1 FAQ
1.How can I place an order for RD18ES-T1 through Aetrix?
Please submit a Request for Quotation (RFQ) for RD18ES-T1 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 RD18ES-T1 reliable?
The price and inventory of RD18ES-T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD18ES-T1 is usually 5 days.
3.What payment methods are accepted for RD18ES-T1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD18ES-T1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD18ES-T1?
RD18ES-T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD18ES-T1 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 RD18ES-T1?
For technical support, including RD18ES-T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD18ES-T1 requirements.
6.How does Aetrix verify that RD18ES-T1 is sourced from the original manufacturer or authorized distributors?
All RD18ES-T1 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 RD18ES-T1 meets industry standards.
7.What is the process for return or replacement of RD18ES-T1?
All RD18ES-T1 units undergo pre-shipment inspection (PSI). If there is an issue with RD18ES-T1, 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 RD18ES-T1 part is unused and in its original packaging.
Return procedure for RD18ES-T1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD18ES-T1 Tags
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