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Renesas RD18JS-T1-AZ
- Part No.:
- RD18JS-T1-AZ
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD18JS-T1-AZ.pdf
- Description:
- DIODE ZENER
- Quantity:
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Inventory:58,000
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Product details
Overview
RD18JS-T1-AZ from Renesas Electronics is a 400 mW, DO-34 glass-sealed Zener diode with nominal zener voltage 18.21 V (AB3 suffix), sharp breakdown characteristic, low noise performance (en = 20 µV at 10–500 kHz), and dynamic impedance Zz = 80 Ω at Iz = 5 mA - used for precision voltage reference and waveform clipping in analog signal conditioning circuits.
For engineers reviewing the RD18JS-T1-AZ datasheet, RD18JS-T1-AZ pinout, RD18JS-T1-AZ application, or RD18JS-T1-AZ equivalent, key selection criteria include zener voltage tolerance (±3.0% at 18.21 V), knee impedance Zzk = 0.1 Ω, thermal resistance Rth = 375 °C/W, and compliance with JEDEC DO-34 package dimensions (2.4 mm max body length, blue cathode marking).
Technical Context
This device operates as a two-terminal voltage-reference element relying on controlled reverse-biased avalanche breakdown. Its DHD (Double Heatsink Diode) construction enhances thermal dissipation within the miniature DO-34 package, enabling stable regulation up to 400 mW at TA = 25 °C with derating above 25 °C per Fig. 5.
The RD18JS-T1-AZ exhibits a positive temperature coefficient of +0.06 %/°C near 18 V, confirmed by Fig. 6, and maintains low noise (20 µV RMS, 10–500 kHz) critical for sensor biasing and low-drift reference designs. It is rated for surge reverse power PRSM = 2.4 W (t = 10 µs) per Fig. 9.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage Vz | 18.21 V (AB3 suffix, ±3.0% tolerance at Iz = 5 mA) - sets precise clamping/reference level in feedback or protection circuits |
| Power Dissipation P | 400 mW at TA = 25 °C - defines maximum continuous DC power handling before thermal derating applies |
| Dynamic Impedance Zz | 80 Ω at Iz = 5 mA - determines output voltage stability under load current variation |
| Knee Impedance Zzk | 0.1 Ω at Iz = 0.5 mA - ensures sharp turn-on and minimal voltage droop near regulation threshold |
| Noise Level en | 20 µV RMS (10–500 kHz) - enables use in low-noise analog references without added filtering |
| Surge Reverse Power | 2.4 W (t = 10 µs) - supports transient overvoltage suppression in pulse-loaded applications |
| Junction Temperature | 175 °C - establishes maximum allowable die temperature for reliability-limited operation |
Pinout & Package
RD18JS-T1-AZ uses the standard JEDEC DO-34 axial glass package (2.4 mm max body length, blue cathode band). Cathode is marked with blue color near one end; anode is unmarked lead.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node | Connected to circuit ground or lower-potential node; carries forward current IF ≤ 150 mA |
| Cathode | Zener regulation terminal / Output reference node | Provides stable reverse-biased voltage; marked with blue band; connects to regulated rail or error amplifier input |
Key Features
| Feature | Design Value |
|---|---|
| DO-34 glass seal | Hermetic encapsulation ensures long-term parameter stability and moisture resistance in industrial environments |
| Sharp breakdown | Low knee impedance (Zzk = 0.1 Ω) enables clean voltage limiting with minimal soft transition into regulation |
| Low noise | 20 µV RMS noise (10–500 kHz) supports high-precision analog references without external filtering |
| E24-standard Vz | 18.21 V nominal aligns with IEC 60063 E24 series - simplifies BOM standardization across voltage tiers |
| DHD construction | Double heatsink design improves thermal path from junction to leads, supporting 400 mW rating in mini-package |
Applications
| Industrial Sensor Biasing | Audio Signal Clipping |
|---|---|
|
Use Scenario: Providing stable bias voltage to MEMS pressure sensor bridge amplifiers in factory automation systems. IC Role / Device Role / Timing Role: Two-terminal voltage reference establishing fixed common-mode level for instrumentation amplifier inputs. Use Value: Low 20 µV noise prevents degradation of sub-mV sensor output SNR; sharp knee ensures consistent turn-on across temperature. |
Use Scenario: Limiting peak amplitude of line-level audio signals in analog mixer front-ends to prevent op-amp saturation. IC Role / Device Role / Timing Role: Passive waveform clipper placed across op-amp feedback path to define symmetrical clipping thresholds. Use Value: 80 Ω dynamic impedance minimizes distortion during clipping; DO-34 size allows dense PCB layout in compact audio modules. |
| Power Supply Overvoltage Protection | Reference Voltage Generator |
|
Use Scenario: Safeguarding 15 V DC-DC converter outputs against transient surges exceeding 20 V in embedded control units. IC Role / Device Role / Timing Role: Shunt protector activated when output exceeds 18.21 V, diverting excess current to ground. Use Value: 2.4 W surge rating handles 10 µs transients without failure; 175 °C junction rating supports operation in hot chassis environments. |
Use Scenario: Generating a stable 18.2 V reference for ADC full-scale calibration in test equipment front-ends. IC Role / Device Role / Timing Role: Precision shunt reference supplying known voltage to ADC reference input via low-impedance buffer. Use Value: ±3.0% Vz tolerance and low Zzk ensure <0.1% reference drift under varying load; E24 alignment simplifies calibration traceability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | Vz = 18 V (±5%), Zz = 25 Ω @ 12 mA, DO-41 package (4.5 mm body) | Higher power (1 W), larger footprint, looser tolerance - suitable where space and precision are less constrained | Select when higher surge margin or legacy DO-41 compatibility is required; not drop-in due to size and tolerance mismatch |
| BZX55-C18 | Vz = 18 V (±5%), Zz = 40 Ω @ 5 mA, DO-35 package (3.6 mm body) | Same glass seal but wider Vz tolerance and higher Zz - lower cost for non-critical regulation | Choose for cost-sensitive consumer applications where 20 µV noise and 0.1 Ω knee impedance are unnecessary |
Compared with 1N4746A and BZX55-C18, RD18JS-T1-AZ delivers tighter voltage tolerance (±3.0% vs ±5%), lower noise (20 µV vs >30 µV), and sharper knee behavior (Zzk = 0.1 Ω), making it preferred for precision analog and space-constrained industrial designs.
Availability
RD18JS-T1-AZ is available at Aetrix Electronics and suitable for industrial sensor biasing, audio signal clipping, power supply overvoltage protection, and reference voltage generation requiring stable component supply and long-term parametric consistency.
Supply support for RD18JS-T1-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
Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog and power devices, and system-on-chip solutions for industrial, automotive, and infrastructure markets.
The RD series Zener diodes were developed by Renesas (formerly NEC) for high-stability, low-noise voltage reference and waveform shaping in industrial analog circuits - emphasizing sharp breakdown, thermal robustness, and JEDEC-compliant miniaturization.
FAQ
What is the exact zener voltage and tolerance for RD18JS-T1-AZ?
The RD18JS-T1-AZ has a nominal zener voltage of 18.21 V with ±3.0% tolerance (17.70 V to 18.70 V) when tested at Iz = 5 mA and TA = 25 °C, per the AB3 suffix variant specified in Renesas datasheet D13937EJ5V0DS00. This value is measured using a 40 ms pulse and conforms to E24 standard voltage series.
Does RD18JS-T1-AZ have a specified noise performance?
Yes, RD18JS-T1-AZ exhibits a noise level of 20 µV RMS over the 10–500 kHz bandwidth at TA = 25 °C, as shown in Fig. 8 of the official datasheet. This low-noise characteristic makes RD18JS-T1-AZ suitable for precision analog reference and sensor biasing applications where signal integrity is critical.
What is the thermal resistance and maximum junction temperature of RD18JS-T1-AZ?
RD18JS-T1-AZ has a junction-to-ambient thermal resistance Rth of 375 °C/W (Fig. 7) and a maximum junction temperature Tj of 175 °C (Absolute Maximum Ratings table). These values define its safe operating area under continuous DC load and require appropriate PCB copper area per Fig. 5 for thermal derating above 25 °C ambient.
Is RD18JS-T1-AZ compatible with automated SMT assembly?
No, RD18JS-T1-AZ uses a DO-34 axial glass package with radial leads and is intended for through-hole mounting only. The "T1" suffix denotes tape-and-reel packaging for manual or wave-solder processes, not surface-mount compatibility. For SMT equivalents, consider SOD-123 or SOD-323 packaged Zeners from Renesas' newer series.
What does the "AB3" suffix mean in RD18JS-T1-AZ?
The "AB3" suffix in RD18JS-T1-AZ identifies the tightest voltage bin within the RD18JS family: Vz = 18.21 V (min) to 19.03 V (max) at Iz = 5 mA. Per the datasheet, AB1, AB2, and AB3 represent three progressively tighter tolerance bands - AB3 provides the highest precision option for RD18JS-T1-AZ.
RD18JS-T1-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:
- -
RD18JS-T1-AZ FAQ
1.How can I place an order for RD18JS-T1-AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for RD18JS-T1-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 RD18JS-T1-AZ reliable?
The price and inventory of RD18JS-T1-AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD18JS-T1-AZ is usually 5 days.
3.What payment methods are accepted for RD18JS-T1-AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD18JS-T1-AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD18JS-T1-AZ?
RD18JS-T1-AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD18JS-T1-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 RD18JS-T1-AZ?
For technical support, including RD18JS-T1-AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD18JS-T1-AZ requirements.
6.How does Aetrix verify that RD18JS-T1-AZ is sourced from the original manufacturer or authorized distributors?
All RD18JS-T1-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 RD18JS-T1-AZ meets industry standards.
7.What is the process for return or replacement of RD18JS-T1-AZ?
All RD18JS-T1-AZ units undergo pre-shipment inspection (PSI). If there is an issue with RD18JS-T1-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 RD18JS-T1-AZ part is unused and in its original packaging.
Return procedure for RD18JS-T1-AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD18JS-T1-AZ Tags
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