SG3525A Pulse Width Modulator PWM Controller


In stock

  Ask a Question


Are you looking to design efficient Switched Mode Power Supplies (SMPS) or PWM signals for your power electronics projects? Look no further than the SG3525 Regulating Pulse Width Modulators. This 16-pin IC offers improved performance, requires fewer external parts, and provides versatile control over output voltage. With features like feedback circuitry, current limit protection, and a built-in soft start circuit, the SG3525 is the ideal choice for inverter applications and controlling converter transformers using MOSFET or IGBT.

Features and Specifications

  • Supply Voltage: 8V to 35V
  • Supply Voltage VCC: +40 Vdc
  • Oscillation Range: 100 Hz to 400 kHz
  • 5.1 V Reference Trimmed TO ± 1 %
  • Logic Input: -0.3V to 5.5V
  • Output Current IO: ±500 mA
  • Reference Output Current Iref: 50 mA
  • Oscillator Charging Current: 5 mA
  • Maximum Power Dissipation: 1000 mW
  • Power Dissipation PD: 1000 mW
  • Thermal Resistance, Junction-to-Air RθJA: 100 ˚C/W
  • Thermal Resistance, Junction-to-Case RθJC: 60 ˚C/W
  • Operating Junction Temperature TJ: 150 ˚C
  • Dual-Source/Sink Output Drivers
  • Internal Soft-Start
  • Pulse by Pulse Shutdown
  • Adjustable Dead Time Control
  • Separate Oscillator Sync Terminal
  • Latching PWM to Prevent Multiple Pulses

SG3525 Pinout Configuration

SG3525 Pinout Diagram

Pin Number Pin Name Pin Function
1 INV Inverting Input
2 NINV Non-Inverting Input
3 SYNC Synchronizing IC with an external oscillator frequency
4 OSC. Output Oscillator Output. The frequency of IC is confirmed at this pin
5, 6 CT & RT These pins are used to connect an external capacitor and resistor, respectively, to set up the frequency of the oscillator circuit
7 Discharge (DIS) This pin is used to determine the dead time for IC. A resistor connected between pins 7 and 5 decides the frequency of PWM (or dead time)
8 Soft Start (SS) A capacitor is connected to this pin and ground. It initiates operation softly
9 Compensation (COMP) A compensation pin used to compensate for errors and avoid rapid fluctuations
10 Shutdown A shutdown pin that narrows down PWM signals to the maximum level when set high. Used to shut down the IC’s output in the event of malfunction or unwanted condition
11 Output A Output pin used as an input for external devices
12 VSS Ground pin
13 VC Power pin used to supply input voltage (5-35 V). Connected to a resistor that determines the magnitude of the trigger current to the output current
14 Output B Output pin used as an input for external devices
15 Vin Supply input voltage (8-35 V)
16 Vref Reference pin used to set reference voltage through pins 1 and 2




The SG3525 pulse width modulator IC finds extensive use in various power electronics projects and is particularly well-suited for designing Switched Mode Power Supplies (SMPS). Here are some common applications:

  1. Inverter Systems: The SG3525 is widely employed in inverter applications. It offers dual PWM outputs that operate inversely, facilitating the control of converter transformers and MOSFETs. This makes it an essential component for generating high-quality AC power from a DC source.
  2. SMPS Designs: The IC’s excellent performance and low external parts count make it highly suitable for SMPS designs. By using the SG3525, designers can achieve efficient power conversion with precise control over output voltage and current.
  3. Power Supplies: The SG3525 can be utilized in the design of regulated power supplies. Its feedback circuit enables voltage regulation by comparing the feedback signal with a reference signal. This allows for stable and reliable power output for a wide range of electronic devices.
  4. Motor Speed Control: With its adjustable dead time control and precise PWM generation capabilities, the SG3525 can be employed in motor speed control applications. By modulating the width of the PWM signal, the speed of motors can be regulated with high accuracy.
  5. Lighting Control: The SG3525 can be used for controlling the brightness of lighting systems, such as LED lighting. Its PWM signals can be utilized to adjust the duty cycle and regulate the intensity of the light output.
  6. Audio Amplifiers: The SG3525 can also be incorporated into audio amplifier circuits. Employing PWM techniques to enable efficient power amplification that can contribute to high-quality audio reproduction.
  7. Battery Charging: The SG3525 can be implemented in battery charging systems, providing control over the charging process and maintaining optimal charging parameters.


FAQs and Answers

Q: What is the main purpose of the SG3525 IC?

A: The SG3525 IC is a pulse width modulator used to design Switched Mode Power Supplies (SMPS) and PWM signals for power electronics projects. It offers improved performance, lower external parts count, and various features for efficient power control.

Q: What are the key features of the SG3525 pulse width modulator?

A: The SG3525 offers features such as a feedback circuit for voltage control, current limit protection for safe operation, a built-in soft start circuit for a gentle power-up process, and versatile pin configurations for customization and control.

Q: Can the SG3525 be used in inverter applications?

A: Yes, the SG3525 is commonly used in inverter applications. It provides two main PWM outputs, the inverse of each other, which are connected to external devices to control the converter transformer and implement final operations like MOSFET control.

Q: What is the range of the supply voltage for the SG3525 IC?

A: The SG3525 operates with a supply voltage range of 8V to 35V, allowing compatibility with various power supply configurations.

Q: Does the SG3525 have protection mechanisms?

A: Yes, the SG3525 includes a protection circuit that shuts down the PWM signal based on current limit conditions, ensuring safe operation and preventing any malfunction or unwanted conditions.



There are no reviews yet.

Be the first to review “SG3525A Pulse Width Modulator PWM Controller”

General Enquiries

There are no enquiries yet.