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Renesas RD3.9F-T6-AZ
- Part No.:
- RD3.9F-T6-AZ
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD3.9F-T6-AZ.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
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Product details
Overview
RD3.9F-T6-AZ from Renesas Electronics is a 1 W planar-type silicon Zener diode in DO-41 glass-sealed DHD package, with nominal zener voltage 3.9 V (B grade, ±5% tolerance), dynamic impedance ≤40 Ω at 15 mA, and temperature coefficient −2.5 mV/°C. It serves as a precision voltage reference and surge clamp in low-voltage power rail regulation circuits.
For engineers reviewing the RD3.9F-T6-AZ datasheet, RD3.9F-T6-AZ pinout, RD3.9F-T6-AZ application, or RD3.9F-T6-AZ equivalent, this page delivers verified electrical specs, thermal derating curves, real-world clipping behavior, and direct alternatives for voltage reference and transient suppression design.
Technical Context
This device operates as a reverse-biased breakdown regulator with stable 3.9 V reference under 15 mA test current. Its planar junction structure ensures consistent breakdown characteristics and low leakage (<40 μA at 1.0 V), while the DO-41 glass package provides mechanical robustness and thermal dissipation capability up to 175°C junction temperature.
The RD3.9F-T6-AZ exhibits a negative temperature coefficient of −2.5 mV/°C, making it suitable for temperature-compensated reference designs when paired with positive-TC components. Surge capability reaches 400 W for 10 μs pulses, supporting transient immunity in industrial I/O protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 3.73–4.15 V at IZ = 15 mA - defines stable regulation window for 3.3 V system rails |
| Dynamic Impedance (ZZ) | ≤40 Ω at IZ = 15 mA - ensures minimal output voltage shift under load transients |
| Reverse Current (IR) | ≤40 μA at VR = 1.0 V - guarantees low standby power loss in always-on bias networks |
| Temperature Coefficient (γZ) | −2.5 mV/°C - enables predictable drift compensation in ambient-variable environments |
| Power Dissipation (P) | 1.0 W at TA = 25°C - supports continuous operation in PCB-mounted linear regulators |
| Junction Temperature (Tj) | −65 to +175°C - allows deployment in automotive under-hood and industrial control enclosures |
| Surge Reverse Power (PRSM) | 400 W (t = 10 μs) - absorbs ESD and lightning-induced transients without failure |
Pinout & Package
DO-41 glass axial package with cathode indicated by black band; leads are tinned copper, compatible with wave and reflow soldering. Thermal resistance RthJA varies with PCB copper area (e.g., 200°C/W at 5 mm², 120°C/W at 20 mm²).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to ground or lower-potential rail in shunt regulator configuration |
| Cathode | Zener breakdown terminal / regulated output node | Provides stable 3.9 V reference when reverse-biased above knee voltage |
Key Features
| Feature | Design Value |
|---|---|
| E24-series voltage grading | Enables standardized BOM selection across 3.9 V, 4.3 V, and 4.7 V variants without custom sourcing |
| Planar-type DHD structure | Delivers repeatable breakdown voltage and low parameter spread vs. alloy-junction diodes |
| 1 W power rating with DO-41 footprint | Offers higher dissipation than SOD-123 equivalents while retaining through-hole assembly compatibility |
| Negative γZ at 3.9 V | Permits thermal drift cancellation in mixed-TC reference strings (e.g., with forward-biased diodes) |
| 400 W surge capability | Eliminates need for external TVS in cost-sensitive 3.3 V I/O line protection |
Applications
| Industrial Sensor Signal Conditioning | 3.3 V Microcontroller Power Rail Clamp |
|---|---|
Use Scenario: Stabilizing analog front-end references in 4–20 mA loop-powered sensors operating from unregulated 12–24 V supplies. IC Role / Device Role / Timing Role: Shunt voltage reference and overvoltage limiter for op-amp bias networks and ADC reference dividers. Use Value: Maintains <±1% reference accuracy across −40°C to +85°C ambient via matched γZ compensation, reducing calibration overhead. |
Use Scenario: Protecting GPIO and reset inputs of ARM Cortex-M0+ MCUs against supply overshoot during hot-swap or load-dump events. IC Role / Device Role / Timing Role: Low-leakage clamping element placed between VDD_IO and GND to limit transients to 4.15 V max. Use Value: Prevents latch-up and ESD damage without adding series resistance that degrades signal rise time. |
| Automotive Body Control Module (BCM) Input Protection | Consumer Audio DC Bias Reference |
Use Scenario: Safeguarding LIN bus transceiver enable pins and switch sense inputs exposed to 12 V battery transients. IC Role / Device Role / Timing Role: Transient voltage suppressor absorbing ISO 7637-2 Pulse 1/2a energy before reaching ASIC inputs. Use Value: Withstands 400 W surges at 10 μs without degradation, meeting OEM EMC robustness requirements without discrete TVS cost penalty. |
Use Scenario: Generating precise 3.9 V bias for headphone amplifier input coupling capacitors in portable Bluetooth speakers. IC Role / Device Role / Timing Role: Stable DC offset source ensuring symmetrical AC-coupled signal swing and minimizing pop/click artifacts. Use Value: Low 40 μA leakage at 1.0 V prevents capacitor discharge during pause states, preserving bias integrity over extended idle periods. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4730A | Same 3.9 V nominal, but ±5% tolerance only at 56 mA test current; ZZ = 10 Ω (lower), γZ = −2.0 mV/°C | Higher test current shifts operating point; less suitable for low-current bias networks | Select when lower dynamic impedance is critical and circuit can support ≥56 mA bias current |
| BZX55-C3V9 | Same 3.9 V, ±5%, but rated at 500 mW; ZZ = 90 Ω at 5 mA; DO-35 package (smaller footprint) | Lower power rating limits surge handling; smaller package reduces thermal mass and heatsinking margin | Select for space-constrained PCBs where 400 W surge immunity is not required |
Compared with RD3.9F-T6-AZ, the 1N4730A offers tighter regulation at high bias currents but demands more quiescent power, while the BZX55-C3V9 saves board area at the expense of thermal robustness and low-current stability-making RD3.9F-T6-AZ optimal for industrial-grade 1 W shunt regulation where reliability across temperature and transient stress is prioritized.
Availability
RD3.9F-T6-AZ is available at Aetrix Electronics and suitable for industrial sensor conditioning, 3.3 V microcontroller rail clamping, and automotive body control module input protection requiring stable component supply and long-term lifecycle continuity.
Supply support for RD3.9F-T6-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 delivering microcontrollers, analog, power, and connectivity solutions for industrial, automotive, and enterprise systems.
The RD3.9F-T6-AZ belongs to Renesas' legacy planar Zener diode family designed for precision voltage reference and transient suppression in cost-sensitive, high-reliability embedded power management.
FAQ
What is the exact zener voltage tolerance and test condition for RD3.9F-T6-AZ?
The RD3.9F-T6-AZ has a B-grade zener voltage range of 3.73 V to 4.15 V, measured at IZ = 15 mA for 40 ms after power-on per datasheet D13936EJ5V0DS. This ±5.3% tolerance reflects the full spread across production lots and ensures compatibility with 3.3 V system margins.
Does RD3.9F-T6-AZ support surface-mount assembly?
No-RD3.9F-T6-AZ uses a DO-41 glass axial package with radial leads intended for through-hole mounting. It is not compatible with standard SMT reflow profiles or pick-and-place equipment. For SMT equivalents, consider Renesas' NSZ series or industry-standard SOD-123 Zeners.
What is the maximum allowable reverse voltage before breakdown for RD3.9F-T6-AZ?
The RD3.9F-T6-AZ begins controlled zener breakdown at approximately 3.73 V (minimum VZ). Below this, reverse leakage remains ≤40 μA at 1.0 V. Operation below 3.73 V is safe and non-regulating; sustained reverse bias above 4.15 V risks thermal runaway if power dissipation exceeds 1 W.
How does the −2.5 mV/°C temperature coefficient affect RD3.9F-T6-AZ in a 0–70°C operating range?
Over 0–70°C, the RD3.9F-T6-AZ exhibits a total zener voltage shift of −175 mV (−2.5 × 70), resulting in a VZ range of ~3.725 V to ~3.55 V. This predictable drift enables compensation in multi-diode references or informs worst-case tolerance stack-ups in precision analog designs.
Can RD3.9F-T6-AZ be used in parallel for higher power dissipation?
No-RD3.9F-T6-AZ must not be paralleled due to mismatched zener voltages and thermal runaway risk. Its dynamic impedance and temperature coefficient variation between units prevent current sharing. For >1 W applications, use a single higher-rated Zener or switch to active regulation.
RD3.9F-T6-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:
- -
RD3.9F-T6-AZ FAQ
1.How can I place an order for RD3.9F-T6-AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for RD3.9F-T6-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 RD3.9F-T6-AZ reliable?
The price and inventory of RD3.9F-T6-AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD3.9F-T6-AZ is usually 5 days.
3.What payment methods are accepted for RD3.9F-T6-AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD3.9F-T6-AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD3.9F-T6-AZ?
RD3.9F-T6-AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD3.9F-T6-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 RD3.9F-T6-AZ?
For technical support, including RD3.9F-T6-AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD3.9F-T6-AZ requirements.
6.How does Aetrix verify that RD3.9F-T6-AZ is sourced from the original manufacturer or authorized distributors?
All RD3.9F-T6-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 RD3.9F-T6-AZ meets industry standards.
7.What is the process for return or replacement of RD3.9F-T6-AZ?
All RD3.9F-T6-AZ units undergo pre-shipment inspection (PSI). If there is an issue with RD3.9F-T6-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 RD3.9F-T6-AZ part is unused and in its original packaging.
Return procedure for RD3.9F-T6-AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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