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Renesas RD51F
- Part No.:
- RD51F
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD51F.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:8,100
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Product details
Overview
RD51F from Renesas Electronics is a 1 W planar-type silicon Zener diode in DO-41 glass-sealed DHD package, rated for 48–54 V nominal zener voltage at 10 mA test current, with 50 Ω dynamic impedance and −0.5 mV/°C temperature coefficient - used for precision voltage regulation and surge suppression in industrial power supplies.
For engineers reviewing the RD51F datasheet, RD51F pinout, RD51F application, or RD51F equivalent, key selection criteria include its 1 W power rating, tight 48–54 V zener tolerance (B grade), low 50 Ω dynamic impedance at 10 mA, −0.5 mV/°C temperature coefficient, and DO-41 mechanical compatibility with legacy through-hole designs.
Technical Context
The RD51F operates as a two-terminal voltage reference device, maintaining stable reverse breakdown across ambient temperatures from −65°C to +175°C. Its planar junction construction ensures consistent zener characteristics and low leakage under specified reverse bias conditions.
It delivers regulated voltage via controlled avalanche breakdown, with thermal resistance optimized by its Double Heatsink Diode (DHD) structure. The device supports transient surge absorption up to 400 W for 10 μs pulses, per Figure 7 of the datasheet.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 48–54 V at IZ = 10 mA - defines stable regulation range for mid-range DC rail clamping |
| Power Dissipation (P) | 1.0 W at TA = 25°C - sets continuous thermal limit without heatsinking |
| Dynamic Impedance (ZZ) | 50 Ω max at IZ = 10 mA - determines output voltage stability under load variation |
| Reverse Current (IR) | 5 μA max at VR = 39 V - ensures low leakage in standby or high-impedance bias networks |
| Zener Temp. Coefficient (γZ) | −0.5 mV/°C typical - enables predictable drift compensation in temperature-sensitive references |
| Junction Temperature (Tj) | 175°C maximum - defines upper thermal operating boundary for reliability margin |
| Surge Reverse Power (PRSM) | 400 W for t = 10 μs - supports transient overvoltage protection in input-stage clamp circuits |
Pinout & Package
RD51F uses a standard DO-41 axial-leaded glass package (JEDEC-compliant), with cathode indicated by a black band. The device has two terminals: anode and cathode - no internal circuitry or control logic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / reference ground node | Connected to lower-potential side in reverse-bias regulation; carries forward current up to 200 mA |
| Cathode | Zener breakdown terminal / regulated output node | Marked with black band; held at stable VZ when reverse-biased above breakdown threshold |
Key Features
| Feature | Design Value |
|---|---|
| Wide zener voltage range (2–82 V) | Enables single-family standardization across diverse supply rails and protection thresholds |
| E24 series nominal values | Ensures compatibility with standard resistor ladder design practices and BOM consolidation |
| DO-41 glass-sealed DHD structure | Provides robust thermal dissipation and long-term parameter stability in industrial environments |
| B-grade voltage classification | Guarantees 48–54 V tolerance without requiring binning or custom screening |
| 175°C maximum junction temperature | Supports operation in high-ambient applications such as motor drive power stages and LED drivers |
Applications
| Voltage Regulation in Industrial SMPS | Overvoltage Clamp for Microcontroller I/O |
|---|---|
Use Scenario: Stabilizing feedback reference in 48 V-output flyback converters for factory automation controllers. IC Role / Device Role / Timing Role: Zener diode provides precise, passive voltage reference for optocoupler-based secondary-side regulation. Use Value: 50 Ω dynamic impedance and −0.5 mV/°C tempco ensure <±1.5% output variation across −40°C to +85°C ambient. |
Use Scenario: Protecting 3.3 V GPIO pins on Renesas RA-series MCUs against accidental 24 V field-wiring faults. IC Role / Device Role / Timing Role: Acts as fast-acting shunt clamp to divert fault current before internal ESD structures fail. Use Value: 400 W surge rating at 10 μs enables reliable suppression of inductive switching transients without degradation. |
| Surge Absorption in Telecom Line Interfaces | Constant-Current Bias for Optocouplers |
Use Scenario: Front-end protection in PoE-powered Ethernet switches exposed to lightning-induced surges on RJ45 lines. IC Role / Device Role / Timing Role: Primary shunt element in multi-stage TVS+Zener hybrid clamp network. Use Value: DO-41 package allows direct PCB mounting near connectors; 175°C Tj rating sustains repeated surge events. |
Use Scenario: Setting stable bias current for linear-mode operation of PC817-series optocouplers in isolated feedback loops. IC Role / Device Role / Timing Role: Provides temperature-compensated current source via series resistor + RD51F reference. Use Value: Low 5 μA leakage at 39 V ensures minimal error in bias current calculation across wide temperature ranges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5355BRLG (ON Semiconductor) | 51 V nominal, 5 W rating, DO-201AD package, 10 Ω ZZ, +3.5 mV/°C γZ | Higher power handling but larger footprint and positive tempco - unsuitable where thermal mass or drift direction matters | Choose only if system requires >1 W continuous dissipation and board space permits DO-201AD |
| BZX85C51 (Nexperia) | 51 V nominal, 1.3 W rating, DO-41 package, 70 Ω ZZ, −2.5 mV/°C γZ | Same package but higher dynamic impedance and stronger negative tempco - reduces regulation accuracy in precision references | Acceptable for non-critical clamping; avoid where <50 Ω ZZ or tight tempco is required |
Compared with RD51F, the 1N5355BRLG offers higher surge capacity but introduces layout incompatibility and opposite temperature drift, while the BZX85C51 matches the DO-41 form factor but degrades regulation stability due to higher impedance and stronger negative coefficient.
Availability
RD51F is available at Aetrix Electronics and suitable for industrial power supplies, telecom surge protection, and microcontroller I/O protection requiring stable component supply and long-lifecycle support.
Supply support for RD51F 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 specializing in microcontrollers, analog, and power devices for industrial, automotive, and infrastructure markets.
The RD51F belongs to Renesas' legacy planar Zener diode family designed for cost-effective, high-reliability voltage reference and transient suppression in standard-grade industrial equipment.
FAQ
What is the exact zener voltage tolerance for RD51F?
The RD51F has a guaranteed zener voltage range of 48 V to 54 V at 10 mA test current (IZ), corresponding to the B-grade classification per the D13936EJ5V0DS datasheet. This 6 V window reflects the full allowable spread - not a ±X% specification - and applies under 40 ms pulse test conditions.
Can RD51F be used in surface-mount designs?
No, RD51F is exclusively offered in the axial-leaded DO-41 glass package and is not available in SMD variants. It requires through-hole mounting with appropriate pad clearance and lead-forming. For SMT alternatives, consider Renesas' NZ9F51V or equivalent SOD-123 Zeners - but note these differ in thermal performance and surge capability.
What is the maximum reverse voltage RD51F can block before breakdown?
The RD51F begins controlled zener breakdown at minimum 48 V, and its absolute maximum non-breakdown reverse voltage is defined by the test condition VR = 39 V (where IR ≤ 5 μA). Operating continuously above 39 V risks entering breakdown; sustained reverse bias above 54 V may exceed safe operating area limits.
Does RD51F meet RoHS requirements?
Yes, RD51F complies with EU RoHS Directive 2011/65/EU as confirmed by Renesas' environmental compliance documentation. The device contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits, and is marked "RoHS compliant" in official product change notices.
How does RD51F's temperature coefficient affect long-term stability?
RD51F exhibits a typical zener voltage temperature coefficient of −0.5 mV/°C, meaning its regulated voltage decreases by ~0.5 mV per degree Celsius rise in junction temperature. Over a 100°C rise (e.g., from 25°C to 125°C), this yields ~50 mV total drift - critical for applications requiring sub-0.1% reference stability across temperature.
RD51F 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:
- -
RD51F FAQ
1.How can I place an order for RD51F through Aetrix?
Please submit a Request for Quotation (RFQ) for RD51F 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 RD51F reliable?
The price and inventory of RD51F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD51F is usually 5 days.
3.What payment methods are accepted for RD51F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD51F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD51F?
RD51F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD51F 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 RD51F?
For technical support, including RD51F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD51F requirements.
6.How does Aetrix verify that RD51F is sourced from the original manufacturer or authorized distributors?
All RD51F 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 RD51F meets industry standards.
7.What is the process for return or replacement of RD51F?
All RD51F units undergo pre-shipment inspection (PSI). If there is an issue with RD51F, 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 RD51F part is unused and in its original packaging.
Return procedure for RD51F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD51F Tags
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MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
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