MBR2535CTLG Schottky Barrier Rectifier: Datasheet, Pinout, and Application Circuits
The MBR2535CTLG is a dual common-cathode Schottky barrier rectifier renowned for its high current capability and low forward voltage drop. This power diode is a staple in modern switching power supplies and reverse polarity protection circuits, where efficiency and thermal performance are paramount.
Datasheet Overview and Key Specifications
Housed in a TO-263AB (D2PAK) surface-mount package, the MBR2535CTLG is designed for high-power applications. Its key electrical characteristics define its performance envelope:
Average Forward Rectified Current (Io): 25A per diode at a case temperature of +110°C. This high current rating makes it suitable for demanding power paths.
Repetitive Peak Reverse Voltage (VRRM): 35V. This voltage rating targets common low-voltage applications like 12V and 24V systems.
Forward Voltage Drop (VF): A maximum of 0.55V at +10A per diode and +25°C. This low VF is the primary advantage of Schottky diodes, leading to significantly lower power losses and higher efficiency compared to standard PN-junction rectifiers.
Reverse Leakage Current (IR): 0.5mA at +25°C and rated voltage. This parameter increases with temperature, a critical consideration for thermal management.
Operating Junction Temperature (Tj): -65°C to +150°C.
Pinout and Package Configuration
The MBR2535CTLG is a dual common-cathode device. This means two independent Schottky diodes are integrated into a single package with their cathodes tied together internally. The TO-263AB package has three pins:
1. Pin 1 (Anode 1): The anode terminal of the first diode.
2. Pin 2 (Common Cathode): The common connection for both cathodes. This pin is also connected to the large metal tab, which is essential for efficient heat dissipation.
3. Pin 3 (Anode 2): The anode terminal of the second diode.
The metal tab serves as the primary thermal path, and it is electrically connected to the common cathode. Proper insulation between the tab and the heatsink is required if the heatsink is at a different potential.
Application Circuits
The MBR2535CTLG's characteristics make it ideal for several key applications:
1. Switching Power Supply (SMPS) Output Rectification: Its most common use is in the secondary side of switch-mode power supplies, particularly in synchronous rectification circuits or as the main output rectifier in low-voltage, high-current designs (e.g., for servers, telecom equipment). The fast switching speed and low VF minimize switching losses and improve overall power supply efficiency.
2. Reverse Polarity Protection: The diode can be placed in series with the power input rail. While effective, this method causes a voltage drop equal to VF. A more efficient alternative uses the diode in a "reverse battery protection" circuit with a relay or MOSFET, where the low VF minimizes losses in the protection path.
3. Freewheeling / Flyback Diode: In inductive load circuits, such as motor drives or solenoid controllers, the MBR2535CTLG is used as a freewheeling diode. It provides a safe path for the current to decay when the driving switch (like a MOSFET) turns off, protecting the switch from voltage spikes.
4. OR-ing Circuits: In redundant power systems (e.g., with two power supplies feeding a single load), Schottky diodes are used to isolate the supplies. The common-cathode configuration of the MBR2535CTLG is perfectly suited for building such circuits, preventing current from back-feeding into a failed or lower-voltage unit.
The MBR2535CTLG stands out as a robust and highly efficient solution for power management tasks demanding high current and low loss. Its dual common-cathode design in a thermally efficient package offers designers flexibility and reliability. When selecting a rectifier for low-voltage, high-current applications where thermal management and efficiency are critical, this Schottky diode remains a top-tier choice.
Keywords:
Schottky Barrier Rectifier, Low Forward Voltage, Output Rectification, Common-Cathode, Thermal Management
