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Renesas RD27F-AZ
- Part No.:
- RD27F-AZ
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD27F-AZ.pdf
- Description:
- DIODE ZENER
- Quantity:
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Inventory:17,200
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Product details
Overview
RD27F-AZ from Renesas Electronics is a 1 W planar-type silicon Zener diode in DO-41 glass-sealed DHD (Double Heatsink Diode) package, with nominal zener voltage 27 V (B3 grade: 26.72–28.43 V), dynamic impedance ≤16 Ω at 10 mA, and reverse current ≤10 μA at 21 V. It serves as a precision voltage reference and overvoltage clamp in power supply regulation and surge protection circuits.
For engineers reviewing the RD27F-AZ datasheet, RD27F-AZ pinout, RD27F-AZ application, or RD27F-AZ equivalent, this page delivers verified electrical specs, thermal derating curves, temperature coefficient behavior, JEDEC DO-41 mechanical data, and direct alternative options for voltage reference and transient suppression design.
Technical Context
This Zener diode operates in reverse breakdown mode with tightly controlled voltage tolerance (±3.2% for B3 grade), exhibits a positive zener voltage temperature coefficient of +24 mV/°C (typical), and maintains stable regulation under DC and short-duration surge conditions up to 400 W (t = 10 μs). Its planar junction structure ensures reproducible breakdown characteristics and low noise performance.
The device's thermal resistance is defined by PCB copper area (e.g., 120 °C/W at S = 5 mm²), and its dynamic impedance drops with increasing test current - 16 Ω at 10 mA, falling to lower values at higher bias. It is rated for junction temperatures up to 175 °C and storage from −65 to +175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 26.72–28.43 V (B3 grade, tested at 40 ms after power-on; enables ±3.2% tolerance voltage reference) |
| Power Dissipation (P) | 1.0 W at TA = 25 °C; derates linearly above 25 °C per Figure 1 (supports continuous regulation in compact layouts) |
| Dynamic Impedance (ZZ) | ≤16 Ω at IZ = 10 mA (ensures minimal output voltage shift under load variation) |
| Reverse Current (IR) | ≤10 μA at VR = 21 V (guarantees low leakage in high-impedance bias networks) |
| Zener Temp. Coefficient (γZ) | +24 mV/°C (typical at IZ = 10 mA; allows predictable drift compensation in temp-stable references) |
| Surge Reverse Power (PRSM) | 400 W at t = 10 μs (enables single-pulse transient suppression without device failure) |
| Package | DO-41 (JEDEC standard); glass-sealed, axial lead, cathode marked with black band (mechanically robust, industry-compatible footprint) |
Pinout & Package
RD27F-AZ uses a two-terminal DO-41 axial package: anode and cathode leads extend from opposite ends of a cylindrical glass body, with cathode identified by a black band. No internal circuitry or multi-pin configuration exists - it is a passive two-terminal device.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node in shunt regulator | Connected to lower potential side; carries forward current up to 200 mA; defines return path for zener bias current |
| Cathode | Zener breakdown terminal / Regulated output node | Marked with black band; connected to higher potential; maintains stable voltage relative to anode during reverse bias operation |
Key Features
| Feature | Design Value |
|---|---|
| E24-standardized zener voltage series | Enables standardized BOM selection across 2–82 V range; RD27F-AZ fits common 27 V system rails |
| Planar-type glass-sealed DHD structure | Provides consistent breakdown characteristics, low noise, and long-term stability vs. alloy-junction alternatives |
| 1 W power rating with thermal derating curve | Supports sustained dissipation in PCB-mounted applications with ≥5 mm² copper pour (Rth ≈ 120 °C/W) |
| B3-grade voltage binning | Guarantees tight 26.72–28.43 V window (±3.2%) - critical for precision clamping and reference accuracy |
| Positive temperature coefficient (+24 mV/°C) | Permits temperature-compensated designs when paired with negative-coefficient devices or resistive networks |
Applications
| Power Supply Voltage Reference | Overvoltage Clamp in DC-DC Converters |
|---|---|
Use Scenario: Providing stable 27 V reference for feedback loop of isolated flyback converter. IC Role / Device Role / Timing Role: Shunt reference diode regulating optocoupler LED current to maintain output voltage accuracy. Use Value: Maintains ±1.5% output regulation over line/load/temperature with <16 Ω dynamic impedance limiting error contribution. |
Use Scenario: Clamping gate-source voltage of MOSFET in synchronous buck controller during switching transients. IC Role / Device Role / Timing Role: Transient voltage suppressor limiting VGS to safe level (<30 V) during dV/dt events. Use Value: Absorbs 400 W surge pulses (10 μs) without degradation, protecting gate oxide integrity. |
| Surge Protection in Industrial I/O | Waveform Limiting in Signal Conditioning |
Use Scenario: Protecting 24 V PLC analog input channel from induced lightning surges on field wiring. IC Role / Device Role / Timing Role: Primary shunt clamp diverting surge energy before front-end amplifier. Use Value: Activates at 26.72 V, clamping to <32 V within nanoseconds; low ZZ ensures fast response and minimal let-through voltage. |
Use Scenario: Limiting audio signal peaks in microphone preamplifier to prevent ADC saturation. IC Role / Device Role / Timing Role: Bidirectional limiter (with series diode) clipping positive excursions at ~27 V. Use Value: Low leakage (<10 μA) avoids DC offset; E24-standard value simplifies calibration against known 27 V source. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference and transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor 1N4750A | 27 V nominal, ±5% tolerance (wider than RD27F-AZ B3), 1.3 W rating, DO-41, ZZ = 20 Ω @ 11 mA | Higher power margin but looser voltage tolerance; less suitable for precision references requiring <±3.5% | Select when cost sensitivity outweighs tight voltage binning needs; verify thermal layout for 1.3 W dissipation. |
| Vishay 1N5254B | 27 V nominal, ±5% tolerance, 0.5 W rating, DO-35, ZZ = 35 Ω @ 10 mA | Lower power and higher impedance limit use to low-current bias/reference roles; not suitable for surge clamping | Choose only for space-constrained, low-power bias networks where 0.5 W and DO-35 footprint are mandatory. |
Compared with RD27F-AZ, the 1N4750A offers higher power headroom but sacrifices voltage precision, while the 1N5254B reduces size and cost at the expense of surge capability and regulation stiffness - RD27F-AZ uniquely balances 1 W rating, B3-grade tolerance, and DO-41 manufacturability for industrial power and protection designs.
Availability
RD27F-AZ is available at Aetrix Electronics and suitable for industrial power supplies, PLC I/O protection, and DC-DC converter feedback circuits requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for RD27F-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 global semiconductor leader formed in 2010 via merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.
RD27F-AZ belongs to Renesas' legacy planar Zener diode family designed for reliable voltage regulation and transient suppression in standard-grade industrial equipment - emphasizing manufacturability, JEDEC compliance, and long-term parametric consistency.
FAQ
What is the exact zener voltage range for RD27F-AZ?
The RD27F-AZ is specified in the B3 grade, with a guaranteed zener voltage range of 26.72 V to 28.43 V at IZ = 10 mA and TA = 25 °C. This ±3.2% tolerance is tighter than standard B-grade parts and supports precision regulation tasks where voltage accuracy is critical. The RD27F-AZ datasheet confirms this binning in Table on page 4 of Document No. D13936EJ5V0DS.
Does RD27F-AZ have a positive or negative temperature coefficient?
RD27F-AZ exhibits a positive zener voltage temperature coefficient of +24 mV/°C (typical) at IZ = 10 mA, as documented in the Electrical Characteristics table on page 4. This means its regulated voltage increases with rising temperature - a key factor when designing temperature-stable references or compensating networks. The RD27F-AZ's coefficient is confirmed in Figure 4 and Figure 5 of the same datasheet.
What is the maximum surge power RD27F-AZ can withstand?
RD27F-AZ is rated for a surge reverse power of 400 W at pulse width t = 10 μs, as stated in the Absolute Maximum Ratings table (page 2) and illustrated in Figure 7. This rating applies under non-repetitive conditions and assumes proper PCB thermal design. The RD27F-AZ's ability to absorb such transients makes it suitable for primary-level surge suppression in 24 V industrial systems.
Is RD27F-AZ compatible with automated through-hole assembly?
Yes, RD27F-AZ uses the JEDEC-standard DO-41 package with axial leads and glass body, fully compatible with standard wave soldering and selective soldering processes. Its 3.0 mm diameter and 25 mm minimum lead length meet IPC-7351 requirements for through-hole placement. The RD27F-AZ's mechanical dimensions are explicitly shown in the Package Drawing on page 2 of the datasheet.
What is the reverse leakage current specification for RD27F-AZ?
RD27F-AZ guarantees reverse current IR ≤ 10 μA at VR = 21 V and TA = 25 °C, per the Electrical Characteristics table on page 4. This low leakage ensures minimal error in high-impedance reference dividers and prevents unintended bias current paths. The RD27F-AZ's leakage performance is validated across the full B3 voltage range and supports stable operation in battery-backed or low-power monitoring circuits.
RD27F-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:
- -
RD27F-AZ FAQ
1.How can I place an order for RD27F-AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for RD27F-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 RD27F-AZ reliable?
The price and inventory of RD27F-AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD27F-AZ is usually 5 days.
3.What payment methods are accepted for RD27F-AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD27F-AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD27F-AZ?
RD27F-AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD27F-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 RD27F-AZ?
For technical support, including RD27F-AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD27F-AZ requirements.
6.How does Aetrix verify that RD27F-AZ is sourced from the original manufacturer or authorized distributors?
All RD27F-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 RD27F-AZ meets industry standards.
7.What is the process for return or replacement of RD27F-AZ?
All RD27F-AZ units undergo pre-shipment inspection (PSI). If there is an issue with RD27F-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 RD27F-AZ part is unused and in its original packaging.
Return procedure for RD27F-AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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