The SG3525A is a PWM (pulse width modulation) control IC designed for efficient power control. This IC is used for applications such as SMPS power supplies, Inverters, and PWM motor speed control circuits. The IC provides an optimized power control system due to its unique features.
SG3525A Pinout
Features of SG3525A
The IC SG3525A comes with several features, that are listed below
- Operating voltage of 8V to 35V DC
- It operates at a frequency of up to 500KHz
- For efficient power management, it uses Low start-up current
- The inbuilt circuit consists of the oscillator which eliminates the external clock source to produce signals.
- Deadtime control is implemented to improve efficiency and protection.
- The under-voltage lockout (UVLO) protects from working the device from improper voltage.
- During the Power ON it protects the in-rush current because of the soft start feature.
- The dual output for push-pull operation.
Pin Configuration
| Pin Number | Function |
|---|---|
| Pin1 INV | Inverting input of the error amplifier |
| NON-INV (Pin 2) | Non-inverting input of the error amplifier |
| Dead Time Control (Pin 4) | Adjusts dead time between output pulses. |
| CT (Pin 5) | Timing capacitor for oscillator |
| RT (Pin 6) | Timing resistor for oscillator |
| Pin 7 | Discharge |
| Pin 8 | soft start |
| Compensation (Pin 9) | Connects to external components for loop stabilization. |
| Shutdown (Pin 10) | Provides external control for system protection. |
| Outputs (Pins 11 & 14) | PWM outputs for driving MOSFETs or power transistors. |
| GND (Pin 12) | Ground connection. |
| VREF (Pin 16) | 5V reference voltage output. |
| VCC (Pin 15) | Supply voltage input. |
| Pin13 | Vc |
| Pin3 | sync |
Working Principle
The SG3525 IC works as a PWM controller by generating two PWM signals in the output pins of Pin 11 and Pin 14. These signals will be used to control the power transistors or MOSFETS.
In voltage regulators, The internal error amplifier compares the reference voltage with the feedback voltage provided to the IC from the output.
The PWM signal frequency is set by the capacitor and resistor connected to the RT and CT pin of the IC.
The deadtime control circuit will ensure the output transistor or MOSFET does not conduct simultaneously.
During the start-up, The soft start function gradually increases the PWM signal to the gate pin or base pin of MOSFET or transistor to avoid the sudden rush of current through the components.
Applications of SG3525A
- Switched mode power supply.
- Inverter.
- Battery charger.
- Motor speed controller.
- PWM signal generator circuit.
Conclusion
The SG3525 is a very popular PWM controller IC, Most common in Inverter circuit and PWM battery charger circuit. The built-in features of the oscillator, soft start function, and deadtime control make the IC suitable for most electronic devices. Whether for SMPS, inverters, motor controllers, or battery chargers, the SG3525A is the preferred choice in modern power electronics design.
