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Renesas RD4.3F-AZ
- Part No.:
- RD4.3F-AZ
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD4.3F-AZ.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:16,249
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Product details
Overview
RD4.3F-AZ from Renesas Electronics is a 1 W planar-type silicon Zener diode in DO-41 glass-sealed package, with nominal zener voltage 4.3 V (B3 grade: 4.28–4.55 V), dynamic impedance ≤15 Ω at 40 mA, and reverse current ≤20 μA at 2 V. It serves as a precision voltage reference and overvoltage clamp in power supply regulation circuits.
For engineers reviewing the RD4.3F-AZ datasheet, RD4.3F-AZ pinout, RD4.3F-AZ application, or RD4.3F-AZ equivalent, key selection criteria include its ±0.13 V tolerance (B3 grade), −2.0 mV/°C temperature coefficient, 175°C maximum junction temperature, and suitability for constant-voltage regulation in industrial and consumer-grade power rails.
Technical Context
This device uses a planar-junction structure with double heatsink (DHD) thermal design to sustain 1 W continuous dissipation at 25°C ambient, derating linearly above 25°C per Figure 1. Its low dynamic impedance ensures stable regulation under varying load currents up to 40 mA.
The RD4.3F-AZ exhibits a negative temperature coefficient of −2.0 mV/°C, making it suitable for temperature-compensated references when paired with positive-TC components. Surge reverse power rating is 400 W for 10 μs pulses, supporting transient suppression in DC input stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.28–4.55 V at IZ = 40 mA - defines tight regulation window for 4.3 V reference designs |
| Dynamic Impedance (ZZ) | ≤15 Ω at IZ = 40 mA - ensures minimal output voltage shift under load transients |
| Reverse Current (IR) | ≤20 μA at VR = 2 V - guarantees low leakage in standby or low-power modes |
| Power Dissipation (P) | 1.0 W at TA = 25°C - supports robust operation in compact PCB layouts with adequate copper area |
| Temperature Coefficient (γZ) | −2.0 mV/°C - enables predictable drift compensation in temperature-sensitive analog circuits |
| Junction Temperature (Tj) | 175°C maximum - allows reliable operation in high-ambient industrial environments |
| Surge Reverse Power (PRSM) | 400 W (t = 10 μs) - provides single-pulse ESD/surge immunity without external TVS |
Pinout & Package
RD4.3F-AZ is housed in a DO-41 glass-sealed axial package per JEDEC standard, with cathode indicated by a black band. The device has two terminals: anode and cathode - no internal circuitry or multi-pin configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower potential node; conducts when forward-biased ≥0.7 V |
| Cathode | Zener breakdown terminal | Marked with black band; referenced to regulated output voltage in reverse-bias operation |
Key Features
| Feature | Design Value |
|---|---|
| Wide zener voltage range (2–82 V) | Enables standardized BOM across multiple rail voltages using same family process |
| E24 series nominal values | Ensures compatibility with common resistor/capacitor value sets for filter and bias networks |
| Planar-type DHD structure | Improves thermal coupling to PCB copper, reducing effective RthJA by ~30% vs. conventional DO-41 |
| B3 voltage classification | Delivers tighter 4.28–4.55 V tolerance versus generic B grade (4.03–4.55 V), improving reference accuracy |
| 175°C max junction temperature | Supports operation in sealed enclosures or near heat-generating components without derating penalties |
Applications
| Power Supply Voltage Reference | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Stabilizing feedback node in linear regulator (e.g., 78L05) or adjustable buck converter error amplifier. IC Role / Device Role / Timing Role: Provides fixed 4.3 V reference for comparator threshold or op-amp setpoint. Use Value: Maintains ±1.5% output regulation across line/load variations due to low ZZ and tight VZ tolerance. |
Use Scenario: Clamping 5 V logic rail against ESD or inductive kickback in microcontroller I/O protection. IC Role / Device Role / Timing Role: Shunts excess energy to ground before voltage exceeds safe logic threshold. Use Value: Limits transient peaks to ≤4.55 V with <20 ns response, preventing latch-up in CMOS inputs. |
| Waveform Limiting Circuit | Constant-Current Bias Source |
Use Scenario: Trimming audio signal peaks in preamplifier stage to prevent distortion in analog-to-digital conversion. IC Role / Device Role / Timing Role: Acts as bidirectional limiter by conducting symmetrically in forward and reverse breakdown. Use Value: Clips signal excursions beyond ±4.3 V with <0.5 V hysteresis, preserving waveform fidelity below threshold. |
Use Scenario: Establishing stable bias current for LED driver or transistor amplifier stage. IC Role / Device Role / Timing Role: Sets emitter/base current via series resistor, leveraging stable VZ for IBIAS = (VCC − 4.3 V)/R. Use Value: Delivers ±2% current stability over −40°C to +85°C due to compensated γZ and low ZZ. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4733A | Same 5.1 V nominal rating, but RD4.3F-AZ offers 4.3 V target and tighter B3 tolerance (±3.0%) vs. 1N4733A's ±5%. | 1N4733A is optimized for 5.1 V rails; RD4.3F-AZ better matches 4.3 V LDO feedback or 3.3 V system clamping with margin. | Select RD4.3F-AZ when precise 4.3 V regulation or lower temperature drift (−2.0 vs. −2.5 mV/°C) is required. |
| BZX55-C4V3 | BZX55-C4V3 has wider tolerance (4.08–4.52 V), higher ZZ (≤20 Ω), and lower surge rating (300 W @ 10 μs). | BZX55-C4V3 suits cost-sensitive consumer designs; RD4.3F-AZ preferred for industrial systems needing higher reliability and thermal margin. | Choose RD4.3F-AZ for applications requiring guaranteed 40 mA test current compliance and 175°C Tj rating. |
Compared with 1N4733A and BZX55-C4V3, RD4.3F-AZ delivers superior voltage accuracy at 4.3 V, lower dynamic impedance for tighter regulation, and higher surge endurance-making it optimal for industrial power monitoring and precision reference circuits where long-term stability matters.
Availability
RD4.3F-AZ is available at Aetrix Electronics and suitable for industrial power supplies, consumer electronics voltage clamping, and embedded system reference circuits requiring stable component supply and full traceability.
Supply support for RD4.3F-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 specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.
RD4.3F-AZ belongs to Renesas' legacy planar Zener diode family designed for general-purpose voltage regulation and protection in standard-grade applications including office equipment, communications gear, and industrial controls.
FAQ
What is the exact zener voltage tolerance for RD4.3F-AZ?
The RD4.3F-AZ is specified in B3 grade, with a zener voltage range of 4.28 V to 4.55 V at 40 mA test current. This ±0.135 V tolerance (±3.1%) is tighter than standard B grade (±5%), ensuring higher accuracy in voltage reference and clamping applications where RD4.3F-AZ is deployed.
Does RD4.3F-AZ meet RoHS requirements?
Yes, RD4.3F-AZ complies with EU RoHS Directive restrictions on hazardous substances. As a Renesas Electronics product manufactured after 2006, it contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above allowable thresholds-confirmed in Renesas' environmental compliance documentation for the RD2.0F–RD82F series.
What is the maximum allowable reverse surge power for RD4.3F-AZ?
RD4.3F-AZ supports a non-repetitive surge reverse power of 400 W at pulse width t = 10 μs, as defined in Figure 7 of the datasheet. This rating enables RD4.3F-AZ to absorb transient overvoltages without failure, provided pulse repetition remains infrequent and average power stays within 1 W limits.
Can RD4.3F-AZ be used in place of a 5.1 V zener diode?
No-RD4.3F-AZ is specifically rated for 4.3 V nominal zener voltage and is not a functional substitute for 5.1 V devices like 1N4733A. Using RD4.3F-AZ in a 5.1 V circuit would cause under-regulation or premature clamping; always match the target rail voltage when selecting RD4.3F-AZ or any zener diode.
What thermal derating applies to RD4.3F-AZ above 25°C ambient?
RD4.3F-AZ must be derated linearly above 25°C ambient temperature, with power dissipation reduced by 8.3 mW/°C (1 W ÷ 120°C thermal range to 145°C case limit). At 75°C ambient, maximum allowable power drops to 0.58 W-critical for RD4.3F-AZ deployment in enclosed or high-temperature industrial enclosures.
RD4.3F-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:
- -
RD4.3F-AZ FAQ
1.How can I place an order for RD4.3F-AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for RD4.3F-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 RD4.3F-AZ reliable?
The price and inventory of RD4.3F-AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD4.3F-AZ is usually 5 days.
3.What payment methods are accepted for RD4.3F-AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD4.3F-AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD4.3F-AZ?
RD4.3F-AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD4.3F-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 RD4.3F-AZ?
For technical support, including RD4.3F-AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD4.3F-AZ requirements.
6.How does Aetrix verify that RD4.3F-AZ is sourced from the original manufacturer or authorized distributors?
All RD4.3F-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 RD4.3F-AZ meets industry standards.
7.What is the process for return or replacement of RD4.3F-AZ?
All RD4.3F-AZ units undergo pre-shipment inspection (PSI). If there is an issue with RD4.3F-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 RD4.3F-AZ part is unused and in its original packaging.
Return procedure for RD4.3F-AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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