TO-252-3L 650V SiC Schottky Diode Datasheet - Package 6.6x9.84x2.3mm - Voltage 650V - Current 10A - English Technical Documentation

1. Product Overview

This document provides the complete technical specifications for a high-performance Silicon Carbide (SiC) Schottky Barrier Diode (SBD). The device is designed for high-voltage, high-frequency switching applications where efficiency and thermal management are critical. It is housed in a surface-mount TO-252-3L (DPAK) package, offering a robust thermal and electrical interface for power circuit designs.

The core advantage of this SiC Schottky diode lies in its material properties. Unlike traditional silicon PN-junction diodes, a Schottky diode has a metal-semiconductor junction, which inherently provides a lower forward voltage drop (V_F) and, crucially, near-zero reverse recovery charge (Q_c). This combination significantly reduces both conduction and switching losses, enabling higher system efficiency and power density.

The target markets for this component are advanced power conversion systems. Its primary benefits of high efficiency and high-speed switching make it ideal for modern, compact, and high-reliability power supplies.

2. In-Depth Technical Parameter Analysis

2.1 Electrical Characteristics

The electrical parameters define the operational boundaries and performance of the diode under various conditions.

• Repetitive Peak Reverse Voltage (V_RRM): 650V. This is the maximum reverse voltage the diode can withstand repeatedly. It defines the voltage rating for applications like Power Factor Correction (PFC) stages operating from universal AC mains (85-265VAC).
• Continuous Forward Current (I_F): 10A. This is the maximum average forward current the device can conduct continuously, limited by its thermal characteristics. The datasheet specifies this at a case temperature (T_C) of 25°C.
• Forward Voltage (V_F): 1.48V (Typ.) at I_F=10A, T_J=25°C. This low V_F is a key benefit of the SiC Schottky technology, directly reducing conduction losses (P_loss = V_F * I_F). Note that V_F has a positive temperature coefficient, increasing to approximately 1.9V at 175°C junction temperature.
• Reverse Current (I_R): 2µA (Typ.) at V_R=520V, T_J=25°C. This low leakage current contributes to high efficiency in blocking state.
• Total Capacitive Charge (Q_c): 15nC (Typ.) at V_R=400V. This is arguably the most critical parameter for switching performance. Q_c represents the charge that must be supplied/displaced to change the voltage across the diode's junction capacitance. A low Q_c translates to minimal switching losses and enables operation at very high frequencies.
• Capacitance Stored Energy (E_C): 2.2µJ (Typ.) at V_R=400V. This parameter, derived from the junction capacitance, indicates the energy stored in the diode's electric field when reverse-biased. It must be considered in resonant circuit designs.

2.2 Maximum Ratings and Thermal Characteristics

These parameters define the absolute limits for safe operation and the device's ability to manage heat.

• Surge Non-Repetitive Forward Current (I_FSM): 16A for a 10ms half-sine wave. This rating indicates the diode's ability to withstand short-term overloads, such as inrush currents.
• Junction Temperature (T_J): Maximum 175°C. Operating the device above this temperature can cause permanent damage.
• Thermal Resistance, Junction-to-Case (R_θJC): 3.2°C/W (Typ.). This low thermal resistance is crucial for effective heat transfer from the silicon die to the package case and, subsequently, to the heatsink or PCB. The total power dissipation (P_D) is listed as 44W, but this is primarily limited by the maximum T_J and the system's ability to remove heat (R_θCA).

3. Performance Curve Analysis

The datasheet includes several characteristic curves essential for design engineers.

• V_F-I_F Characteristics: This graph shows the relationship between forward voltage and forward current at different junction temperatures. It is used to calculate precise conduction losses under actual operating conditions, not just at the 25°C typical point.
• V_R-I_R Characteristics: Illustrates the reverse leakage current as a function of reverse voltage and temperature. This is critical for estimating standby losses and ensuring stable blocking performance at high temperatures.
• V_R-C_t Characteristics: Shows how the total diode capacitance (C_t) decreases with increasing reverse voltage (V_R). This non-linear capacitance impacts high-frequency switching behavior and resonant circuit design.
• Maximum I_F vs. Case Temperature (T_C): A derating curve that defines how the maximum allowable continuous forward current decreases as the case temperature rises. This is fundamental for thermal design.
• Power Dissipation vs. Case Temperature: Similar to the current derating, this curve shows how much power the device can dissipate based on its case temperature.
• I_FSM vs. Pulse Width (P_W): Provides the surge current capability for pulse durations other than the standard 10ms, allowing assessment of fault condition tolerance.
• E_C-V_R Characteristics: Graphs the stored capacitive energy versus reverse voltage, useful for loss calculations in soft-switching topologies.
• Transient Thermal Resistance (Z_θJC) vs. Pulse Width: This curve is vital for evaluating thermal performance during short switching pulses. The effective thermal resistance for a single short pulse is lower than the steady-state R_θJC.

4. Mechanical and Package Information

4.1 Package Dimensions

The device uses the industry-standard TO-252-3L (DPAK) surface-mount package. Key dimensions from the outline drawing include:

• Overall Length (H): 9.84 mm (Typ.)
• Overall Width (E): 6.60 mm (Typ.)
• Overall Height (A): 2.30 mm (Typ.)
• Lead Pitch (e1): 2.28 mm (Basic)
• Tab Dimensions (D1 x E1): 5.23 mm x 4.83 mm (Typ.)

The large metal tab serves as the primary thermal path (connected to the cathode) and must be properly soldered to a corresponding copper pad on the PCB for effective heat sinking.

4.2 Pin Configuration and Polarity

The pinout is clearly defined:

• Pin 1: Cathode (K)
• Pin 2: Anode (A)
• Case (Tab): Cathode (K)

Important: The case (the large metal tab) is electrically connected to the cathode. This must be considered during PCB layout to avoid short circuits. The tab must be isolated from other nets unless intentionally connected to the cathode node.

4.3 Recommended PCB Pad Layout

A suggested footprint for surface mounting is provided. This layout is optimized for solder joint reliability and thermal performance. It typically includes a large central pad for the tab with thermal vias to inner copper layers or a bottom-side heatsink, plus two smaller pads for the anode and cathode leads.

5. Soldering and Assembly Guidelines

While specific reflow profiles are not detailed in this excerpt, general guidelines for power SMD packages apply.

• Reflow Soldering: Standard lead-free (Pb-Free) reflow profiles are suitable. The large thermal mass of the tab may require slight profile adjustments (e.g., longer soak time or higher peak temperature) to ensure complete solder reflow under the tab.
• Thermal Vias: For optimal thermal performance, the PCB pad for the tab should incorporate multiple thermal vias filled with solder during reflow. These vias conduct heat to internal ground planes or a bottom-side copper pour.
• Mounting Torque: If an additional screw is used to secure the package to a heatsink (through the hole in the tab), the maximum torque is specified as 8.8 N·cm (or 8 lbf-in) for an M3 or 6-32 screw. Exceeding this can damage the package.
• Storage Conditions: The device should be stored in a dry, anti-static environment within the temperature range of -55°C to +175°C.

6. Application Suggestions

6.1 Typical Application Circuits

This diode is specifically designed for the following applications:

• Power Factor Correction (PFC) in Switch-Mode Power Supplies (SMPS): Used as the boost diode in continuous conduction mode (CCM) or transition mode (TM) PFC circuits. Its high V_RRM handles the boosted voltage, while its low Q_c minimizes switching losses at high PFC frequencies (often 65-100 kHz+), improving overall efficiency.
• Solar Inverters: Employed in the boost stage of photovoltaic (PV) micro-inverters or string inverters. High efficiency is paramount for maximizing energy harvest.
• Uninterruptible Power Supplies (UPS): Used in the rectifier/charger and inverter stages to improve efficiency and reduce size.
• Motor Drives: Can be used in freewheeling or clamp diode positions in inverter bridges driving motors, benefiting from high-speed switching.
• Data Center Power Supplies: Server power supplies and telecom rectifiers demand very high efficiency (e.g., 80 Plus Titanium). This diode's characteristics help meet these stringent requirements.

6.2 Design Considerations

• Thermal Design: The low R_θJC is only effective if heat is removed from the case. Adequate PCB copper area, thermal vias, and possibly an external heatsink are required. Use the derating curves to determine safe operating currents at your estimated maximum case temperature.
• Switching Loss Calculation: For hard-switching applications, switching losses are primarily capacitive. The loss per cycle can be approximated as 0.5 * C_oss(V) * V² * f_sw. The Q_c and E_C parameters provide more accurate methods for loss estimation.
• Parallel Operation: The datasheet states the device is suitable for parallel operation without thermal runaway. This is due to the positive temperature coefficient of V_F; if one diode heats up, its V_F increases, causing current to shift to cooler parallel devices, promoting natural current sharing.
• Snubber Circuits: Due to the very fast switching and low Q_rr, SiC Schottky diodes can sometimes cause higher voltage overshoot (ringing) from parasitic inductance. Careful layout to minimize stray inductance and potentially the use of an RC snubber may be necessary.

7. Technical Comparison and Advantages

Compared to traditional silicon fast recovery diodes (FRDs) or even silicon carbide MOSFET body diodes, this SiC Schottky diode offers distinct advantages:

• vs. Silicon PN Diode: The most significant difference is the absence of reverse recovery charge (Q_rr). A silicon diode has a large Q_rr, causing significant switching losses and reverse recovery current spikes. The SiC Schottky's Q_c is purely capacitive, leading to "essentially no switching losses" as stated in the benefits.
• vs. Silicon Schottky Diode: Silicon Schottky diodes have low V_F and fast switching but are limited to low voltage ratings (typically <200V). SiC technology enables Schottky performance at much higher voltages (650V and beyond).
• Higher System Efficiency: The combination of low V_F and negligible switching losses directly increases power supply efficiency across the load range.
• Reduced Cooling Requirements: Lower losses mean less heat generated. This can allow for smaller heatsinks or even passive cooling, reducing system cost, size, and weight.
• Higher Frequency Operation: Enables power supply designs to operate at higher switching frequencies. This allows the use of smaller magnetic components (inductors, transformers), further increasing power density.

8. Frequently Asked Questions (Based on Technical Parameters)

Q: The V_F is 1.48V, which seems higher than some silicon diodes. Is this a disadvantage?
A: While some silicon diodes may have a lower V_F at low currents, their V_F increases significantly at high temperature and current. More importantly, the switching losses of a silicon diode (due to Q_rr) are typically orders of magnitude higher than the capacitive switching losses of this SiC Schottky. The total loss (conduction + switching) of the SiC device is almost always lower in high-frequency applications.

Q: Can I use this diode directly as a replacement for a silicon diode in my existing circuit?
A: Not without careful review. While the pinout may be compatible, the switching behavior is drastically different. The lack of reverse recovery current can lead to higher voltage overshoot due to circuit parasitics. The gate drive for the associated switching transistor may need adjustment, and snubber circuits might require re-tuning. Thermal performance will also differ.

Q: What is the main cause of failure for this diode?
A> The most common failure modes for power diodes are thermal overstress (exceeding T_Jmax) and voltage overstress (exceeding V_RRM due to transients). Robust thermal design, proper voltage derating, and protection against voltage spikes (e.g., with TVS diodes or RC snubbers) are essential for reliability.

9. Practical Design Case Study

Scenario: Designing a 500W, 80 Plus Platinum efficiency server power supply with a CCM PFC front-end.
Design Choice: Selecting the boost diode.
Analysis: A traditional 600V silicon ultrafast diode might have a Q_rr of 50-100 nC. At a PFC switching frequency of 100 kHz and a bus voltage of 400V, the switching loss would be substantial. By using this SiC Schottky diode with a Q_c of 15 nC, the capacitive switching loss is reduced by approximately 70-85%. This loss saving directly improves full-load efficiency by 0.5-1.0%, helping to meet the Platinum standard. Furthermore, the reduced heat generation allows for a smaller heatsink on the PFC stage, saving space and cost in the final product.

10. Operating Principle Introduction

A Schottky diode is formed by a metal-semiconductor junction, unlike a standard PN-junction diode which uses semiconductor-semiconductor. When a suitable metal (e.g., Nickel) is deposited on an N-type Silicon Carbide (SiC) wafer, a Schottky barrier is created. Under forward bias, electrons from the semiconductor gain enough energy to cross this barrier into the metal, allowing current flow with a relatively low voltage drop. Under reverse bias, the barrier widens, blocking current. The key distinction is that this is a majority-carrier device; there is no injection and subsequent storage of minority carriers (holes in this case) in the drift region. Therefore, when the voltage is reversed, there is no stored charge that needs to be removed (reverse recovery), only the charging/discharging of the junction capacitance. This fundamental physics is what enables the high-speed switching and low Q_c performance.

11. Technology Trends

Silicon Carbide (SiC) power devices represent a significant trend in power electronics, moving beyond the material limits of traditional silicon. The wider bandgap of SiC (3.26 eV for 4H-SiC vs. 1.12 eV for Si) provides inherent advantages: higher breakdown electric field (allowing thinner, lower-resistance drift layers for a given voltage), higher thermal conductivity (better heat dissipation), and ability to operate at higher temperatures. For diodes, the Schottky structure on SiC enables the combination of high voltage rating with fast switching, a combination unattainable with silicon. The ongoing development focuses on reducing specific on-resistance (R_DS(on)) for SiC MOSFETs and further lowering V_F and capacitance for SiC Schottky diodes, while also improving manufacturing yields to reduce cost. The adoption is driven by global demands for higher energy efficiency in everything from electric vehicles to renewable energy systems.