KA3525A Controller: Circuit, Pinout, and Datasheet

The KA3525A is a monolithic integrated circuit with all of the control circuitry required for a pulse width modulating regulator. In the chip will find a voltage reference, an error amplifier, a pulse width modulator, an oscillator, an under-voltage lockout, a soft start circuit, and the output driver.

This is a 16-pin chip with a reference output current of roughly 50mA and a supply voltage of around 40V. The operation temperature is 0 to 70 degrees Celsius, whereas the storage temperature is -65 to 150 degrees Celsius. The output sink current is 500mA and the power dissipation is 100mW.

This pulse-width modulation regulator IC has 16 pins and creates two PWM signals that are complementary to one another. The output voltage is controlled by feedback circuitry that compares the feedback signal to a reference voltage. This component is commonly used in switch-mode power supplies and other electronic circuits.

If the feedback signal approaches its limit, the device's shutdown protection circuit cuts off the PWM signal.

Pinout

• Pin 1 is the inverting pin, while pin 2 is the non-inverting pin.

• The duty cycle increases if the voltage on the non-inverting pin is smaller than the voltage on the inverting pin.

• Pin 3 is used for the synchronization of two waves, while Pin 4 is an oscillator's output pin.

• Pins 5, 6, and 7 are used to change the PWM frequency.

• We can change the value of the discharge resistor, CT capacitor, and RT resistor to change the frequency of PWM.

• Pin 8 SS is a soft start pin that allows the output signal to be enabled after a certain amount of time. The soft-start time is directly proportional to the capacitance.

• Pin 9 is a compensation pin that is used to mitigate rapid output voltage signal swings.

• Pin 10 is referred to as the shutdown pin. When the current hits its limit, the PWM signal is turned off.

• The output pins (pins 11 and 14) are used to supply input to the MOSFETs. A MOSFET driver circuit is included into the KA3525A.

• The power pins are pins 13 and 15. Vc should be between 5 and 35 volts, while Vin should be between 8 and 35 volts.

• Pin 16 is the reference pin, which is used to modify the reference voltage via pins 1 and 2.

Symbol

Footprint

3D Model

• 5V ±1% Reference

• Oscillator Sync Terminal

• Internal Soft Start

• Deadtime Control

• Under Voltage Lockout

Functional Block Diagram

Test Circuit

• Consumer power electronics applications such as pure sine wave inverters

• Generate a regulated voltage in a boost converter and a buck converter

• Use as other consumer electronics

Package

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