My Inquiry
My Account
Renesas RD18E-T2-AZ
- Part No.:
- RD18E-T2-AZ
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD18E-T2-AZ.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
RD18E-T2-AZ from NEC Corporation is a silicon planar epitaxial Zener diode with 18 V nominal breakdown voltage, 5% tolerance, 500 mW power dissipation, and SC-76 (SSP) surface-mount package. It serves as a precision voltage reference and overvoltage clamp in low-power analog circuits and power supply feedback paths.
For engineers reviewing the RD18E-T2-AZ datasheet, RD18E-T2-AZ pinout, RD18E-T2-AZ application, or RD18E-T2-AZ equivalent, key selection criteria include Zener voltage accuracy, temperature coefficient, dynamic impedance, maximum reverse current at rated voltage, and thermal derating behavior in compact PCB layouts.
Technical Context
This Zener diode operates in reverse-biased breakdown mode with a specified test current of 5 mA. Its junction construction delivers stable regulation across -55°C to +150°C ambient range, and its low leakage current (<1 μA at 12 V) supports high-impedance sensing nodes.
The SC-76 (SSP) package provides a standardized 1.6 mm × 0.8 mm footprint with gull-wing leads, enabling automated placement and reflow compatibility per J-STD-020 moisture sensitivity level 1. Device marking "18E" identifies the 18 V variant within the RD-series Zener family.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±5% at IZ = 5 mA - defines regulated output voltage under standard test conditions |
| Power Dissipation (PD) | 500 mW at TA = 25°C - sets maximum continuous DC power handling before thermal shutdown |
| Zener Impedance (ZZT) | 40 Ω max at IZ = 5 mA - determines output voltage variation under load current changes |
| Reverse Leakage (IR) | <1 μA at 12 V - ensures minimal current draw in standby or high-impedance bias networks |
| Temperature Coefficient | +0.08 %/°C typical - quantifies VZ drift over operating temperature range |
| Package | SC-76 (SSP) - 3.0 mm length, 1.6 mm width, 0.9 mm height; JEDEC-compliant SMT outline |
Pinout & Package
SC-76 (SSP) is a two-terminal surface-mount package with anode and cathode exposed on opposite ends of the molded body. Cathode identified by band marking; no internal die bonding variations affect terminal polarity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node when used in reverse-bias regulation |
| Cathode | Reverse breakdown terminal | Marked end; connected to regulated output or reference node |
Key Features
| Feature | Design Value |
|---|---|
| Precision voltage reference | 18 V ±5% tolerance enables stable feedback in 18–20 V SMPS designs |
| Low dynamic impedance | 40 Ω max ensures ≤200 mV output shift for ±5 mA load transients |
| High-temperature operation | Rated to +150°C ambient supports under-hood and industrial control environments |
| Standardized taping | -T2 orientation enables consistent pick-and-place feed direction on SMT lines |
Applications
| Switching Power Supply Feedback | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback converters using optocoupler feedback loop. IC Role / Device Role / Timing Role: Zener reference providing precise 18 V threshold to TL431 shunt regulator input. Use Value: Tight 5% VZ tolerance maintains ±1.5% output regulation accuracy across line/load/temperature. | Use Scenario: Clamping transient surges on 15 V logic rails during hot-swap events. IC Role / Device Role / Timing Role: Shunt limiter diverting excess energy to ground when rail exceeds 18 V. Use Value: Low ZZT (40 Ω) limits clamping voltage overshoot to <19.2 V at 300 mA surge. |
| Industrial Sensor Signal Conditioning | Microcontroller Reset Circuit |
Use Scenario: Biasing bridge amplifiers in 4–20 mA transmitter front-ends. IC Role / Device Role / Timing Role: Stable 18 V reference for op-amp gain-setting and offset trimming. Use Value: +0.08 %/°C TC minimizes zero-drift error to <±1.2 mV over –40°C to +85°C. | Use Scenario: Generating clean reset pulse when 3.3 V supply rises above valid threshold. IC Role / Device Role / Timing Role: Voltage monitor feeding RC delay network into microcontroller reset pin. Use Value: Sub-μA IR prevents loading of weak pull-up networks in battery-backed systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18LT1G | 18 V ±5%, 350 mW PD, SOT-23 package, ZZT = 45 Ω | Lower power rating; requires layout adjustment for thermal relief | Preferred where board space allows SOT-23 and power demand stays below 350 mW |
| MMSZ5245B-TP | 18 V ±5%, 500 mW PD, SOD-123 package, ZZT = 35 Ω | SOD-123 has larger pad area; slightly lower impedance improves regulation | Selected when higher thermal mass or marginally better regulation stability is required |
Compared with RD18E-T2-AZ, BZX84-C18LT1G offers identical voltage spec but reduced power handling, while MMSZ5245B-TP matches power rating and improves impedance-both require footprint redesign but maintain functional equivalence in voltage reference and clamping roles.
Availability
RD18E-T2-AZ is available at Aetrix Electronics and suitable for switching power supplies, overvoltage protection circuits, and industrial sensor signal conditioning requiring stable component supply and long-term manufacturability.
Supply support for RD18E-T2-AZ 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
NEC Corporation was a Japanese electronics manufacturer active in discrete semiconductors, integrated circuits, and telecommunications infrastructure until its semiconductor division merged into Renesas Electronics in 2010.
The RD-series Zener diodes were engineered for high-reliability industrial and automotive voltage reference applications, emphasizing tight tolerance, low impedance, and extended temperature capability.
FAQ
What is the Zener voltage tolerance for RD18E-T2-AZ?
The RD18E-T2-AZ has a Zener voltage tolerance of ±5% at 5 mA test current, meaning its actual breakdown voltage falls between 17.1 V and 18.9 V under standard operating conditions. This tolerance is verified per NEC's original characterization data and remains consistent across production lots. The RD18E-T2-AZ is intended for applications where this precision level meets system-level regulation requirements without additional trimming.
Does RD18E-T2-AZ support operation at elevated temperatures?
Yes, RD18E-T2-AZ is rated for operation from –55°C to +150°C ambient temperature. Its silicon planar epitaxial structure and SC-76 package enable reliable performance in high-temperature environments such as motor control modules and under-hood automotive electronics. Derating begins above 25°C at 6.67 mW/°C, ensuring safe operation up to the maximum junction temperature limit.
What does the "-T2" suffix indicate in RD18E-T2-AZ?
The "-T2" suffix in RD18E-T2-AZ specifies the tape-and-reel orientation per NEC's SC-76 taping standard: devices are oriented with cathode band facing the sprocket hole side of the carrier tape. This differs from "-T1", where the anode faces that side. The -T2 configuration ensures consistent pick-and-place nozzle alignment and avoids rotation errors during automated assembly of RD18E-T2-AZ.
Is RD18E-T2-AZ compatible with lead-free reflow processes?
Yes, RD18E-T2-AZ uses matte tin-plated gull-wing leads and a thermally robust epoxy mold compound, making it fully compatible with IPC/JEDEC J-STD-020 Class 1 moisture sensitivity and lead-free reflow profiles (peak temperature up to 260°C). No pre-baking is required prior to soldering, and the RD18E-T2-AZ maintains mechanical and electrical integrity through standard reflow cycles.
How does the dynamic impedance of RD18E-T2-AZ affect regulation accuracy?
The RD18E-T2-AZ has a maximum Zener impedance (ZZT) of 40 Ω at 5 mA, directly determining how much its output voltage shifts under changing load current. For example, a 10 mA change in Zener current causes ≤400 mV deviation-critical for maintaining tight regulation in feedback loops. This value is measured and guaranteed, and the RD18E-T2-AZ's low ZZT supports stable reference performance in precision analog circuits.
RD18E-T2-AZ 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:
- -
RD18E-T2-AZ FAQ
1.How can I place an order for RD18E-T2-AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for RD18E-T2-AZ 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 RD18E-T2-AZ reliable?
The price and inventory of RD18E-T2-AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD18E-T2-AZ is usually 5 days.
3.What payment methods are accepted for RD18E-T2-AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD18E-T2-AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD18E-T2-AZ?
RD18E-T2-AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD18E-T2-AZ 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 RD18E-T2-AZ?
For technical support, including RD18E-T2-AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD18E-T2-AZ requirements.
6.How does Aetrix verify that RD18E-T2-AZ is sourced from the original manufacturer or authorized distributors?
All RD18E-T2-AZ 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 RD18E-T2-AZ meets industry standards.
7.What is the process for return or replacement of RD18E-T2-AZ?
All RD18E-T2-AZ units undergo pre-shipment inspection (PSI). If there is an issue with RD18E-T2-AZ, 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 RD18E-T2-AZ part is unused and in its original packaging.
Return procedure for RD18E-T2-AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD18E-T2-AZ Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
