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Renesas RD39M-T1B-AT
- Part No.:
- RD39M-T1B-AT
- Manufacturer:
- Renesas
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
RD39M-T1B-AT.pdf
- Description:
- RD39M-T1B-AT - ZENER DIODES 200
- Quantity:
- Payment:
- Shipping:
Inventory:75,000
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Product details
Overview
RD39M-T1B-AT from Renesas Electronics is a 200 mW, 3-pin mini-mold planar zener diode with a nominal zener voltage of 39 V (37–41 V range at 2 mA), dynamic impedance of 100 Ω max at 2 mA, and reverse current ≤2 μA at 30 V. It serves as a precision voltage reference or surge absorber in low-power analog signal conditioning and power rail stabilization circuits.
For engineers reviewing the RD39M-T1B-AT datasheet, RD39M-T1B-AT pinout, RD39M-T1B-AT application, or RD39M-T1B-AT equivalent, key selection criteria include its ±5% zener tolerance (Class B), SC-59 package compatibility, thermal impedance profile, and suitability for constant-voltage regulation in space-constrained consumer and industrial control modules.
Technical Context
This device operates as a two-terminal voltage-reference element relying on controlled reverse-breakdown conduction. Its planar construction ensures stable zener characteristics across temperature, with a typical temperature coefficient of +0.04 %/°C near 39 V - indicating mild positive drift above 25°C ambient.
The RD39M-T1B-AT is rated for 100 W non-repetitive surge power at 10 μs pulse width and supports continuous operation up to 150°C junction temperature. Its 200 mW steady-state dissipation derates linearly above 25°C ambient per the published P–TA curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.0–41.0 V at IZ = 2 mA - defines usable regulation window for mid-range voltage references. |
| Dynamic Impedance (ZZ) | ≤100 Ω at IZ = 2 mA - indicates moderate regulation stiffness; suitable for low-current biasing, not high-precision feedback. |
| Power Dissipation (P) | 200 mW at TA = 25°C - sets maximum continuous DC load in compact PCB layouts without heatsinking. |
| Reverse Current (IR) | ≤2 μA at VR = 30 V - confirms low leakage below breakdown, critical for standby power integrity. |
| Junction Temperature (Tj) | −55 to +150°C - enables deployment in extended-temperature industrial environments without derating penalties. |
| Surge Power (PRSM) | 100 W at tT = 10 μs - provides transient overvoltage clamping capability for ESD and inductive spike suppression. |
Pinout & Package
RD39M-T1B-AT uses the SC-59 (JEITA) 3-pin mini-mold package with lead frame exposed on the bottom surface. Pin 1 is NC (no connection), Pin 2 is anode (A), and Pin 3 is cathode (K). The package is compatible with standard SMT reflow profiles and supports automated placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | No Connection (NC) | Electrically isolated; must remain unconnected to avoid parasitic coupling or mechanical stress. |
| 2 | Anode (A) | Connected to lower-potential node in reverse-bias configuration; determines forward conduction path during fault conditions. |
| 3 | Cathode (K) | Connected to higher-potential node; carries regulated output voltage when used as shunt reference. |
Key Features
| Feature | Design Value |
|---|---|
| Planar process construction | Ensures repeatable zener voltage distribution and long-term stability under thermal cycling. |
| E24-standard zener voltage grading | Supports interoperability with common resistor and capacitor series in analog design workflows. |
| SC-59 package with NC pin | Enables mechanical anchoring and thermal relief while isolating unused terminal from circuit nodes. |
| 150°C maximum junction temperature | Permits operation in sealed enclosures or near heat-generating components without forced cooling. |
Applications
| Industrial Sensor Signal Conditioning | USB-C Port Overvoltage Protection |
|---|---|
|
Use Scenario: Stabilizing reference voltage for 12-bit ADC front-end in temperature transmitters operating at 85°C ambient. IC Role / Device Role / Timing Role: Shunt voltage reference providing 39 V clamp to protect op-amp input stage from supply rail transients. Use Value: Maintains <2 μA leakage at 30 V, minimizing offset error in high-impedance sensor bridges. |
Use Scenario: Secondary-level surge suppression on VBUS line in portable docking stations compliant with USB PD 3.0. IC Role / Device Role / Timing Role: Fast-acting clamping diode absorbing 100 W/10 μs spikes induced by hot-plug events. Use Value: Limits peak VBUS excursion to ≤41 V, preventing damage to downstream USB controller ICs rated for 45 V abs max. |
| Programmable Logic Controller (PLC) Input Module | LED Driver Constant-Current Bias |
|
Use Scenario: Providing stable 39 V rail for optocoupler LED drive in 24 V DC digital input isolation stages. IC Role / Device Role / Timing Role: Zener regulator establishing fixed bias point independent of field-wiring resistance variations. Use Value: Delivers consistent LED forward current despite ±15% supply ripple, ensuring reliable optical coupling margin. |
Use Scenario: Setting reference voltage for LM317-based constant-current sink driving high-brightness white LEDs. IC Role / Device Role / Timing Role: Precision voltage source defining IOUT = 1.25 V / RSET in adjustable current regulator topology. Use Value: Enables ±5% current accuracy across 0–70°C due to predictable +0.04 %/°C tempco 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 |
|---|---|---|---|
| 1N4739A (ON Semiconductor) | Same 39 V nominal rating, but DO-41 package (larger footprint), 1 W power rating, 9 Ω ZZ. | Better regulation stiffness and thermal headroom; unsuitable for ultra-compact SMT layouts. | Select when higher surge energy handling or lower dynamic impedance is required, and board area permits through-hole or larger SMD. |
| BZX55-C39 (Vishay) | 39 V, 500 mW, DO-35 package, ±5% tolerance, ZZ = 90 Ω at 5 mA. | Higher test current shifts regulation point; requires different bias network design. | Choose for legacy designs using DO-35 footprints or where 5 mA test current aligns with existing bias schemes. |
Compared with 1N4739A and BZX55-C39, RD39M-T1B-AT offers superior space efficiency in high-density SMT assemblies and tighter thermal response due to SC-59 package mass, though with higher ZZ and lower surge capacity - making it optimal for cost-sensitive, size-constrained industrial controls rather than high-reliability power rails.
Availability
RD39M-T1B-AT is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB-C protection circuits, PLC input modules, and LED driver bias networks requiring stable component supply and RoHS-compliant sourcing.
Supply support for RD39M-T1B-AT 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 devices, and timing solutions for industrial, automotive, and infrastructure markets.
The RD2.0M–RD47M series was designed as a standardized family of low-power, high-reliability zener diodes targeting cost-effective voltage referencing and transient suppression in consumer and general-purpose industrial electronics.
FAQ
What is the zener voltage tolerance for RD39M-T1B-AT?
The RD39M-T1B-AT has a Class B zener voltage rating of 37.0–41.0 V at 2 mA test current, corresponding to ±5.1% tolerance about the nominal 39 V value. This tolerance is defined per E24 standard and verified under pulsed test conditions per the D14716EJ7V0DS datasheet.
Can RD39M-T1B-AT be used in place of a 1N4739A?
RD39M-T1B-AT is not a direct replacement for 1N4739A due to differences in package (SC-59 vs. DO-41), power rating (200 mW vs. 1 W), and dynamic impedance (100 Ω vs. 9 Ω). While both regulate near 39 V, RD39M-T1B-AT suits space-constrained SMT designs with lower power demands, whereas 1N4739A supports higher-energy clamping.
What is the maximum allowable reverse voltage before breakdown for RD39M-T1B-AT?
The RD39M-T1B-AT exhibits ≤2 μA reverse leakage current at 30 V, well below its 37 V minimum zener voltage. Breakdown begins gradually above ~35 V, with full regulation established between 37.0–41.0 V at 2 mA. Operation below 30 V ensures negligible conduction and minimal power loss.
Does RD39M-T1B-AT have a specified temperature coefficient?
Yes - the RD39M-T1B-AT has a typical zener temperature coefficient (γZ) of +0.04 %/°C at 39 V, as shown in Figure 3 of the D14716EJ7V0DS datasheet. This indicates a mild positive drift: zener voltage increases ~15.6 mV per °C rise above 25°C ambient.
Is RD39M-T1B-AT RoHS compliant?
Yes, RD39M-T1B-AT complies with EU RoHS Directive requirements. Renesas Electronics confirms environmental compliance for this part in accordance with applicable regulations, including restriction of lead, cadmium, mercury, hexavalent chromium, PBB, and PBDE substances.
RD39M-T1B-AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-59
RD39M-T1B-AT FAQ
1.How can I place an order for RD39M-T1B-AT through Aetrix?
Please submit a Request for Quotation (RFQ) for RD39M-T1B-AT 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 RD39M-T1B-AT reliable?
The price and inventory of RD39M-T1B-AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RD39M-T1B-AT is usually 5 days.
3.What payment methods are accepted for RD39M-T1B-AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RD39M-T1B-AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RD39M-T1B-AT?
RD39M-T1B-AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RD39M-T1B-AT 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 RD39M-T1B-AT?
For technical support, including RD39M-T1B-AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RD39M-T1B-AT requirements.
6.How does Aetrix verify that RD39M-T1B-AT is sourced from the original manufacturer or authorized distributors?
All RD39M-T1B-AT 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 RD39M-T1B-AT meets industry standards.
7.What is the process for return or replacement of RD39M-T1B-AT?
All RD39M-T1B-AT units undergo pre-shipment inspection (PSI). If there is an issue with RD39M-T1B-AT, 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 RD39M-T1B-AT part is unused and in its original packaging.
Return procedure for RD39M-T1B-AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
RD39M-T1B-AT Tags
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