The "NCP1252ADR2G" is a part number for a component manufactured by ON Semiconductor. The NCP1252ADR2G is a PWM controller designed primarily for power management systems, specifically to help regulate power supplies in applications such as AC-DC converters, battery charging, and more.
Package Type and Pinout Information:
The NCP1252ADR2G is typically available in a DIP-8 or SOIC-8 package, meaning it has 8 pins. Below is a detailed explanation of the pinout functions.
Pinout Details for NCP1252ADR2G (SOIC-8 package):
Pin Number Pin Name Pin Function Description 1 VDD Input power supply pin (typically 12V). Connect to the positive supply voltage source. 2 VSS Ground pin. Connect to the system ground. 3 CS Current sense input. This pin is used to sense the current through an external resistor to set the current limit. 4 GND Ground pin. A second ground pin typically used for proper signal reference in the system. 5 FB Feedback pin. Used to provide the feedback signal to the controller to regulate the output voltage. 6 OCP Overcurrent protection pin. This is used to protect the circuit in case of excessive current draw. 7 OUT Output pin. This pin provides the control output signal to drive external components, such as MOSFETs or transistor s. 8 NC Not connected. This pin may be left floating or unconnected in some designs.Pin Function Details:
Pin 1 (VDD): Supplies the power to the chip, ensuring its internal circuits have the necessary voltage to operate. Typically, it connects to a 12V power rail in a system. Pin 2 (VSS): This is the primary ground connection, ensuring the component operates within a defined reference voltage level. Pin 3 (CS): The current-sensing pin helps monitor the current through an external sense resistor. It’s critical for current regulation and protection against overcurrent conditions. Pin 4 (GND): This is an additional ground reference that can help stabilize the system and improve noise immunity. Pin 5 (FB): The feedback pin receives feedback from the power supply output to regulate and maintain the desired output voltage. In most designs, this pin will connect to a voltage divider network to adjust the regulation threshold. Pin 6 (OCP): The Overcurrent Protection pin monitors the current and ensures the system is protected against high current conditions, typically triggering a shutdown or other protective action if an overcurrent situation occurs. Pin 7 (OUT): This is the output pin, which provides the PWM signal to control external switching devices like MOSFETs or transistors, thus controlling the switching power supply. Pin 8 (NC): Not connected, used as a mechanical pin to ensure proper physical configuration. No electrical connection to the internal circuit.FAQ (Frequently Asked Questions)
1. What is the purpose of the VDD pin on the NCP1252ADR2G?
The VDD pin provides the necessary power supply to the NCP1252ADR2G. It must be connected to a regulated voltage source, typically 12V, to ensure proper operation of the PWM controller.2. Can I leave the NC pin unconnected?
Yes, the NC pin is not electrically connected inside the IC and can be left unconnected in your circuit.3. What should I connect to the CS pin?
The CS pin is for current sensing. Connect it to a sense resistor in series with the load to monitor the current flow for current regulation and overcurrent protection.4. How do I use the FB pin?
The FB pin is used for feedback from the output voltage. A voltage divider circuit or other feedback mechanisms typically connects here to regulate the output voltage.5. Can I connect the GND pin directly to the VSS pin?
Yes, the GND and VSS pins are both ground pins, and they can be connected together to provide a common reference ground.6. Is the OCP pin critical for normal operation?
While not always essential for basic operation, the OCP pin provides an important protection feature. It monitors for overcurrent conditions and can help prevent damage to the power supply.7. What is the output signal from the OUT pin?
The OUT pin provides a PWM signal that drives external power components, such as MOSFETs or other switching devices, to control the output voltage.8. How should I handle the VSS and GND pins in my circuit?
Both VSS and GND should be tied to the system ground, but in some cases, having two distinct ground pins can reduce noise and improve performance.9. Can I use the NCP1252ADR2G for battery charging?
Yes, the NCP1252ADR2G is suitable for use in power management applications, including battery charging, as it can help regulate the power supplied to the battery.10. What type of package is the NCP1252ADR2G available in?
The NCP1252ADR2G is available in an SOIC-8 or DIP-8 package. These packages offer flexibility depending on the needs of your circuit design.11. Does the NCP1252ADR2G have overvoltage protection?
The NCP1252ADR2G does not inherently have overvoltage protection; however, external circuitry can be added to protect the system from overvoltage conditions.12. What is the maximum voltage rating for the NCP1252ADR2G?
The maximum voltage rating for the VDD pin is typically 15V, meaning voltages above this may damage the component.13. How do I set the current limit for the NCP1252ADR2G?
The current limit is set using the CS pin, which is connected to a sense resistor. The voltage across this resistor is monitored to regulate the current.14. How does the NCP1252ADR2G ensure output voltage regulation?
The NCP1252ADR2G uses feedback from the FB pin to regulate the output voltage. By adjusting the duty cycle of the PWM signal, it ensures the output voltage stays within the desired range.15. What is the function of the PWM signal from the OUT pin?
The PWM signal at the OUT pin controls the external power devices like MOSFETs, determining when they turn on and off, thus controlling the power conversion.16. Can the NCP1252ADR2G be used in automotive applications?
Yes, the NCP1252ADR2G can be used in automotive power supplies, but you should verify that it meets the required voltage and environmental specifications for such use.17. What type of protection does the NCP1252ADR2G offer?
The NCP1252ADR2G provides overcurrent protection via the OCP pin and other system-level protections based on external components and design.18. What is the frequency of the PWM signal from the OUT pin?
The frequency of the PWM signal generated by the NCP1252ADR2G depends on the external components used (such as the timing resistor and capacitor ). It is typically in the range of 100 kHz to 1 MHz.19. How do I choose the right sense resistor for the CS pin?
The sense resistor should be chosen based on the desired current limit. The voltage drop across the resistor at the desired current will be used to control the current regulation.20. Can the NCP1252ADR2G be used in a non-isolated power supply?
Yes, the NCP1252ADR2G can be used in both isolated and non-isolated power supply designs, depending on the application and external components used in the system.Summary
The NCP1252ADR2G is a highly versatile and efficient PWM controller for power supply applications. Its compact 8-pin SOIC package allows for integration into space-constrained designs. Proper attention should be given to the pin functions, especially the feedback and current sense connections, for reliable and efficient operation in your design.