The Texas Instruments CSD18532NQ5BT is an N-channel Power MOSFET that is often used in high-efficiency power switching applications such as DC-DC converters, motor drivers, and power supplies. Below is a detailed overview of its pinout, specifications, equivalent circuit, and usage.
1. Pinout of CSD18532NQ5BT
The CSD18532NQ5BT comes in a QFN-5x6 package. Below is the pinout for this package:
Pin 1 (D): Drain
This is the pin where the load is connected. In power applications, this pin is typically connected to the output side of the switching circuit.
Pin 2 (G): Gate
This is the control pin that determines whether the MOSFET is on or off. The voltage applied to this pin relative to the Source pin controls the MOSFET’s operation.
Pin 3 (S): Source
This pin connects to the lower side of the load or ground (depending on application).
Pin 4 (G): Gate
This is an additional gate pin. This is typically used for thermal management and symmetry within the package, but it performs the same function as Pin 2.
Pin 5 (S): Source
Another Source pin for symmetry and thermal balancing. This pin is connected to ground or the lower side of the load in switching applications.
Pin 6 (D): Drain
Another Drain pin for better thermal distribution and current handling. The Drain pin connects to the high-side of the load.
2. Specifications
Here are the key specifications for the CSD18532NQ5BT:
Drain-Source Voltage (Vds): 30V
The maximum voltage that can be applied between the drain and the source of the MOSFET.
Continuous Drain Current (Id): 75A (at 25°C)
The maximum continuous current the MOSFET can handle while in operation.
Gate Threshold Voltage (Vgs(th)): 1.0V - 2.5V
The gate voltage required to turn the MOSFET on, typically around 1.0V to 2.5V for this device.
Rds(on): 5.5mΩ (at Vgs = 10V)
The on-state resistance between the drain and the source when the MOSFET is on. A lower Rds(on) indicates better performance in terms of power efficiency and heat generation.
Total Gate Charge (Qg): 18nC
The total charge required to switch the MOSFET from off to on (or vice versa). This is important in high-speed switching applications.
Package Type: QFN-5x6 (6 pins, surface mount)
Operating Temperature: -55°C to +150°C
The temperature range within which the MOSFET can reliably operate.
3. Equivalent Circuit
The CSD18532NQ5BT is an N-channel MOSFET, so its equivalent circuit consists of:
· Drain (D): Connected to the load or high-side of the circuit.
· Source (S): Connected to ground or the low-side of the circuit.
· Gate (G): Controls the MOSFET's switching operation.
When the MOSFET is ON:
· A positive voltage (greater than the threshold voltage, Vgs(th)) is applied between the gate and source, creating a conductive channel between the drain and source.
· Current flows from the drain to the source when the MOSFET is on.
When the MOSFET is OFF:
· No voltage is applied to the gate (or it is below the threshold), and the channel between the drain and source is not conductive, so no current flows.
The equivalent circuit for the CSD18532NQ5BT can be represented as:
GATE
|
----
|
G
----|----
| |
D S
| |
DRAIN SOURCE
Where:
· D: Drain
· S: Source
· G: Gate
4. Usage
The CSD18532NQ5BT is ideal for applications that require high efficiency, low power loss, and robust performance under high currents and voltages. Typical usage includes:
· DC-DC Converters: The MOSFET is often used in buck, boost, or buck-boost converters due to its high current handling and low Rds(on), which reduces heat dissipation.
· Power Supply Circuits: It is used in power supply units (PSUs) for delivering stable voltage to components with minimal losses.
· Motor Drivers: It can be used for controlling motors, especially in systems where efficiency and thermal management are crucial.
· Load Switching: In high-frequency switching applications, the MOSFET acts as a switch for controlling the power delivered to various loads.
· Battery Management Systems (BMS): For efficient power switching in charging or discharging circuits.
5. Key Features and Benefits
· Low Rds(on) (5.5mΩ): This helps to reduce power loss and heat generation during operation.
· High Drain Current (75A): Capable of handling high current loads.
· Low Gate Charge (Qg): Allows for fast switching speeds, making it ideal for high-frequency applications.
· High Efficiency: Due to its low Rds(on), this MOSFET provides high efficiency in switching applications.
· Thermal Performance: The QFN package provides good thermal dissipation, making it suitable for high-power applications.
· Compact Package: The QFN-5x6 package is compact, making it ideal for space-constrained applications.
Example Circuit Application:
Here's an example of how the CSD18532NQ5BT might be used in a DC-DC buck converter circuit:
Input (Vin) ---> Inductor ---> CSD18532NQ5BT (MOSFET) ---> Output (Vout)
· The MOSFET would switch on and off rapidly, controlling the energy transferred to the load and regulating the output voltage.
· Inductor stores energy and smooths the switching transitions.
· Capacitors help filter out high-frequency noise and smooth the output voltage.
Conclusion
The CSD18532NQ5BT from Texas Instruments is a high-performance N-channel MOSFET used in various power management and switching applications due to its excellent efficiency, low Rds(on), and high current capability. It is ideal for power supply systems, motor drivers, and other high-power, high-efficiency circuits.
