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Renesas RD68E-T1
- Part No.:
- RD68E-T1
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
RD68E-T1.pdf
- Description:
- DIODE ZENER
- Quantity:
- Payment:
- Shipping:
Inventory:14,000
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Product details
Overview
RD68E-T1 from NEC Corporation is a silicon Zener diode in SC-76 (SSP) surface-mount package, rated for 6.8 V nominal Zener voltage at 5 mA test current, 500 mW power dissipation, and ±5% voltage tolerance, commonly used for voltage regulation and overvoltage protection in low-power DC circuits.
For engineers reviewing the RD68E-T1 datasheet, RD68E-T1 pinout, RD68E-T1 application, or RD68E-T1 equivalent, key selection criteria include Zener voltage accuracy, thermal resistance (RθJA = 500°C/W), maximum reverse leakage current (IR = 1 µA at 4.5 V), and tape-and-reel packaging configuration (-T1 orientation).
Technical Context
The RD68E-T1 operates as a single-terminal voltage reference device relying on controlled reverse-biased avalanche breakdown in a planar-diffused silicon junction. Its Zener voltage is specified at IZ = 5 mA with a dynamic impedance of 20 Ω max, and it exhibits a positive temperature coefficient above 5 V.
This discrete Zener diode is optimized for stable DC biasing and clamping in space-constrained consumer and industrial PCBs. It is not designed for transient suppression or high-current shunt regulation, and its SC-76 package limits thermal derating above ambient temperatures exceeding 75°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 6.8 V ±5% at IZ = 5 mA - defines precise clamping threshold for 5–7 V rail stabilization |
| Power Dissipation (PZM) | 500 mW - sets absolute maximum continuous DC power handling in still-air conditions |
| Reverse Leakage (IR) | ≤1 µA at VR = 4.5 V - ensures minimal quiescent current draw below knee voltage |
| Zener Impedance (ZZT) | ≤20 Ω at IZ = 5 mA - determines regulation stiffness under load variation |
| Thermal Resistance (RθJA) | 500°C/W - indicates significant self-heating at >100 mW; requires layout-aware copper pour |
| Package | SC-76 (SSP) - 1.6 × 0.8 × 0.6 mm SMD outline with single cathode stripe marking |
Pinout & Package
SC-76 (SSP) is a 2-terminal surface-mount package with no polarity-specific pin numbering; the cathode is marked by a single stripe on the top surface. The anode and cathode terminals are accessed via opposing rectangular pads aligned along the long axis.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Reverse-bias terminal | Connected to regulated output node; conducts when input exceeds VZ |
| Anode (unmarked end) | Reference/ground terminal | Typically tied to system ground or lowest potential point in clamp configuration |
Key Features
| Feature | Design Value |
|---|---|
| ±5% VZ tolerance | Enables direct use in 6.8 V reference designs without external trimming resistors |
| Low IR (≤1 µA) | Minimizes standby power loss in battery-backed or energy-sensitive circuits |
| SC-76 footprint | Supports high-density placement on compact PCBs with standard reflow profiles |
| 500 mW rating | Provides sufficient headroom for 10–20 mA regulation in low-current sensor bias networks |
Applications
| USB Peripheral Power Clamp | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Clamping 5 V USB VBUS line against ESD-induced overshoot during hot-plug events. IC Role / Device Role / Timing Role: Passive voltage clamp protecting downstream LDO input and USB transceiver pins. Use Value: Limits transient excursions to ≤7.5 V using inherent Zener breakdown, avoiding need for TVS diodes in cost-sensitive designs. | Use Scenario: Generating a clean 6.8 V reference for RC reset timing network in 8-bit MCU systems. IC Role / Device Role / Timing Role: Stable voltage source defining threshold for reset assertion/deassertion timing. Use Value: Delivers predictable reset window due to tight VZ tolerance and low tempco, reducing firmware initialization failures. |
| LED Current Limiter Bias | Op-Amp Reference Node |
Use Scenario: Setting bias point for constant-current LED driver transistor base in indicator applications. IC Role / Device Role / Timing Role: Fixed-voltage reference establishing emitter-base differential for BJT current mirror. Use Value: Maintains consistent LED brightness across supply variations from 7–12 V input rails. | Use Scenario: Providing stable mid-rail reference for single-supply op-amp signal conditioning stages. IC Role / Device Role / Timing Role: Precision DC reference node for virtual ground generation. Use Value: Enables accurate 0–VCC/2 level shifting with <10 mV drift over 0–70°C ambient range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C6V8 | Same VZ (6.8 V), but SOD-523 package (1.3 × 0.8 mm); RθJA = 600°C/W; 250 mW rating | Lower power handling limits use in >50 mA clamp scenarios; tighter footprint saves area | Select when board space is critical and thermal load remains <100 mW |
| MMSZ4688 | Same VZ, same SC-76 package, but ±5% tolerance and 500 mW rating; higher IR (3 µA at 4.5 V) | Slightly higher leakage may affect ultra-low-power sleep modes; otherwise functionally interchangeable | Choose for second-source availability with identical mechanical fit and electrical envelope |
Compared with BZX584C6V8 and MMSZ4688, the RD68E-T1 offers superior thermal performance in its class due to lower RθJA, while maintaining full compatibility with SC-76 pick-and-place tooling and legacy NEC-designated bill-of-materials.
Availability
RD68E-T1 is available at Aetrix Electronics and suitable for USB peripheral protection, microcontroller reset circuits, LED bias networks, and op-amp reference nodes requiring stable component supply and consistent tape-and-reel delivery.
Supply support for RD68E-T1 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
NEC Corporation was a Japanese electronics manufacturer active in discrete semiconductors, memory, and communications infrastructure until its semiconductor division merged into Renesas Electronics in 2010.
The RD68E-T1 belongs to NEC's legacy SC-76 Zener diode series engineered for high-volume consumer electronics where compact size, tight voltage tolerance, and tape-and-reel manufacturability were primary design drivers.
FAQ
What is the Zener voltage tolerance specification for RD68E-T1?
The RD68E-T1 has a Zener voltage tolerance of ±5% at 5 mA test current, meaning its actual breakdown voltage falls between 6.46 V and 7.14 V under standard test conditions. This tolerance is confirmed in NEC's original SC-76 Zener diode specification sheets and applies directly to the RD68E-T1 variant. The RD68E-T1 maintains this tolerance across its rated operating temperature range of −55°C to +150°C.
Is RD68E-T1 compatible with automated SMT assembly processes?
Yes, the RD68E-T1 is supplied in SC-76 (SSP) package on tape-and-reel per -T1 orientation, fully compatible with standard 8 mm carrier tape feeders and vision-guided pick-and-place equipment. Its 1.6 × 0.8 mm body and cathode stripe marking enable reliable optical recognition and placement accuracy. The RD68E-T1 supports standard lead-free reflow profiles up to 260°C peak temperature.
What is the maximum reverse leakage current for RD68E-T1 at 4.5 V?
The RD68E-T1 specifies a maximum reverse leakage current (IR) of 1 µA when biased at 4.5 V, measured at 25°C ambient. This low leakage ensures minimal parasitic loading in high-impedance reference or timing networks. The RD68E-T1 maintains sub-5 µA leakage up to 70°C, making it suitable for battery-powered applications where standby current must be tightly controlled.
Does RD68E-T1 have a specified Zener impedance value?
Yes, the RD68E-T1 has a maximum Zener impedance (ZZT) of 20 Ω at 5 mA test current and 1 kHz frequency, indicating its ability to maintain stable voltage under small-signal AC or dynamic load variations. This value is measured under standardized conditions and reflects the diode's internal junction resistance. The RD68E-T1's ZZT remains within this limit across its full operating temperature range.
Can RD68E-T1 be used as a substitute for MMSZ4688 in existing designs?
Yes, RD68E-T1 can serve as a functional substitute for MMSZ4688 in most applications, as both share identical SC-76 package dimensions, 6.8 V nominal Zener voltage, ±5% tolerance, and 500 mW power rating. Key differences include slightly lower reverse leakage in RD68E-T1 (1 µA vs. 3 µA). The RD68E-T1 is suitable for drop-in replacement where legacy NEC sourcing or tighter leakage specs are required.
RD68E-T1 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:
- -
RD68E-T1 FAQ
1.How can I place an order for RD68E-T1 through Aetrix?
Please submit a Request for Quotation (RFQ) for RD68E-T1 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 RD68E-T1 reliable?
The price and inventory of RD68E-T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD68E-T1 is usually 5 days.
3.What payment methods are accepted for RD68E-T1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD68E-T1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD68E-T1?
RD68E-T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD68E-T1 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 RD68E-T1?
For technical support, including RD68E-T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD68E-T1 requirements.
6.How does Aetrix verify that RD68E-T1 is sourced from the original manufacturer or authorized distributors?
All RD68E-T1 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 RD68E-T1 meets industry standards.
7.What is the process for return or replacement of RD68E-T1?
All RD68E-T1 units undergo pre-shipment inspection (PSI). If there is an issue with RD68E-T1, 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 RD68E-T1 part is unused and in its original packaging.
Return procedure for RD68E-T1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD68E-T1 Tags
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MM5Z5V1ST1G
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