You will find the SG3525A PWM controller very helpful when you need exact control in switching power supply designs that save energy. This integrated circuit controls pulse-width modulation. It helps you control voltage and current very well. Many industries use the SG3525A because it has two outputs and works well every time.
-
Common uses for this controller include:
-
DC-DC converter inverters
-
Solar inverters for renewable energy
-
Motor speed controllers
-
Switching regulators in computer hardware
-
Power management in automotive and industrial systems
-
You can use the SG3525A’s easy-to-understand pin layout and strong integrated circuit design to make stable systems. If you learn about the SG3525A Datasheet and what each pin does, you can build circuits that work well and meet tough rules.
Key Takeaways
-
The SG3525A is a PWM controller that is very reliable. It helps control voltage and current in power circuits. It works with high efficiency and has safety features.
-
You can set the frequency and duty cycle easily. You only need simple external parts. This makes it easy to use in many projects. These include power supplies, inverters, and motor controllers.
-
It is important to know the pinout and what each pin does. This helps you build stable and safe circuits with the SG3525A.
-
The SG3525A has built-in protections like soft-start, shutdown, and undervoltage lockout. These features help protect your circuit and make it more reliable.
-
You can use other ICs instead of the SG3525A. But you should always check datasheets first. Make sure the pinouts and electrical ratings match for smooth use.
SG3525A PWM Controller
Overview
The SG3525A PWM controller helps control power in electronics. It works by turning a signal on and off for different times. The SG3525A has an oscillator that makes two triangle waves. These waves help make two outputs that are opposite each other. The error amplifier checks your feedback voltage and a reference voltage. It changes the pulse width to keep the output steady. You can set the frequency and duty cycle with extra parts. This lets you fit the controller to your project. The SG3525A also has soft-start, shutdown, and overload protection. These features help keep your circuit safe and working well.
Key Features
The SG3525A PWM controller has many helpful features:
-
It works with voltages from 8.0 V to 35 V.
-
It has a 5.1 V reference voltage that is very accurate.
-
You can set the frequency from 100 Hz to 400 kHz.
-
There is a pin for syncing the oscillator.
-
You can control deadtime with just one resistor.
-
It protects your system if the input voltage is too low.
-
Latching PWM stops more than one pulse from happening.
-
It can shut down each pulse for safety.
-
It has two outputs that can give or take up to ±400 mA.
-
The NOR logic output is low when the controller is off.
-
Soft-start works with only a timing capacitor.
-
The shutdown pin lets you turn it off fast and control soft-start.
These features make the SG3525A a good choice for power projects.
Typical Uses
The SG3525A PWM controller is used in many power circuits. It is often found in DC-DC inverters and switching regulators. It helps keep voltage steady in power supplies. Engineers use it in solar inverters to save energy. The SG3525A is also used in cars and factories for power control. Its two outputs and strong driver help control voltage and frequency well. You can use the SG3525 in power supplies, battery chargers, and motor controllers. The SG3525A gives you the control you need for new electronic designs.
SG3525A Pinout
Pin Diagram
When you work with the SG3525A, you need to know the pinout and configuration. The pinout helps you connect the controller correctly in your circuit. Here is a simple table that shows the main pins you will use:
| Pin Number | Pin Name |
|---|---|
| 1 | INV (-) input |
| 2 | N-INV (+) input |
| 5 | CT |
| 6 | RT |
| 9 | COMP |
| 12 | GND |
| 13 | VC |
| 15 | VCC |
| 16 | VREF |
This table gives you a quick look at the standard pin configuration for the SG3525A PWM controller. You can use it as a guide when you build your own circuits.
Pin Functions
Each pin on the SG3525A has a special job. You need to understand the pinout and configuration to use the controller well. The INV (-) input (pin 1) and N-INV (+) input (pin 2) connect to the error amplifier. These pins help you set the feedback for your power supply. The CT (pin 5) and RT (pin 6) pins let you set the timing for the oscillator. This timing controls the frequency of the PWM signals.
The COMP pin (pin 9) connects to the output of the error amplifier. You use this pin to adjust the pulse width. The GND pin (pin 12) is the ground for the whole chip. The VC pin (pin 13) powers the output drivers. The VCC pin (pin 15) is the main power supply for the chip. The VREF pin (pin 16) gives you a stable reference voltage for other parts of your circuit.
You will also find pins for the PWM outputs, shutdown, and sync. The PWM output pins send the control signals to your power switches. The shutdown pin lets you turn off the controller quickly if there is a problem. The sync pin helps you match the timing with other controllers if you use more than one.
Tip: Always double-check the pinout before you connect the SG3525A. A correct pin configuration keeps your circuit safe and working well.
SG3525A Datasheet
Electrical Specs
You should know the main electrical specs before using the SG3525A PWM controller. The sg3525a datasheet gives you all the important details. These specs help you make safe and strong circuits. The table below shows the most important specs:
| Characteristic | Value |
|---|---|
| Supply Voltage Range | 8 V to 35 V |
| Output Current | Up to 200 mA (typical), ±500 mA (max) |
| Oscillator Frequency | Adjustable 100 Hz–400 kHz |
| Output Drivers | Dual-source/sink |
You can change the oscillator frequency by using a different resistor and capacitor on the timing pins. The controller can handle loads up to 500 mA, which is good for many power circuits. The sg3525a datasheet also shows that the chip works with a wide supply voltage range. This makes it useful for many kinds of projects.
Ratings
You should always look at the ratings in the sg3525a datasheet before building your circuit. These ratings show you the safe limits for the controller. If you stay inside these numbers, your design will last longer and work better. Here is a table with the recommended operating conditions:
| Parameter | Recommended Operating Condition |
|---|---|
| Supply Voltage (Vcc) | 8 V to 35 V |
| Operating Temperature | -55°C to 125°C (junction temperature) |
| Oscillator Frequency | 100 Hz to 400 kHz |
| Maximum Power Dissipation | 1000 mW (1 W) |
| Output Current | Up to 400 mA |
You can find these numbers in the sg3525a datasheet under "Absolute Maximum Ratings" and "Recommended Operating Conditions." Always keep your design inside these limits. If you go over them, you could break the controller.
Note: The sg3525a datasheet also has timing diagrams and application notes. These parts help you see how the controller works in real circuits.
Functional Blocks
The sg3525a datasheet has a block diagram that shows how the controller works inside. You will see a few main blocks:
-
Oscillator: This part sets the timing for the PWM signals. You control it with the RT and CT pins.
-
Error Amplifier: This block checks your feedback voltage against a reference. It changes the output to keep your voltage steady.
-
PWM Comparator: This part sets how wide each pulse is. It uses the signal from the error amplifier.
-
Output Drivers: These blocks send the PWM signals to your power switches. They can drive both high and low loads.
-
Shutdown and Soft-Start: These blocks protect your circuit. They let you turn off the controller fast or start it slowly to stop damage.
You can find more details in the block diagram section of the sg3525a datasheet. The datasheet also has notes that show you how to connect each block in real circuits. If you look at these diagrams, you will learn how to use the controller for your own projects.
Tip: Always read the sg3525a datasheet carefully. The diagrams and tables help you avoid mistakes and get the best results from your controller.
SG3525A Circuits
Basic Circuit
You can make a simple circuit with the SG3525 for a switching power supply. In this setup, you connect the SG3525 to a transformer and some MOSFETs. You also add a few timing parts. The oscillator inside lets you set the frequency with one resistor and one capacitor. You do not need many extra parts because the chip has a voltage reference and error amplifier built in. This makes your SMPS design easier and more dependable. The soft-start only needs a timing capacitor. This lets you control how fast your circuit turns on. You get steady output and fewer parts to worry about.
Tip: The SG3525 can drive power transistors by itself, so you do not need extra driver circuits.
Push-Pull Example
A push-pull converter is a common circuit that uses the SG3525. In this design, you use both outputs of the SG3525 to control two MOSFETs in a push-pull setup. The controller sends signals that are out of phase. This means each MOSFET turns on and off at the right time. This setup is efficient because the dead time resistor stops both MOSFETs from turning on together. You avoid shoot-through and lower switching losses. The error amplifier changes the duty cycle to keep the output voltage steady. You can also use the soft-start and shutdown pins for more safety. This circuit is good for SMPS and inverter projects.
Other Designs
The SG3525 works in many other circuits. You can use it for motor speed controllers, solar inverters, and battery chargers. The two outputs help balance power, which is important for steady operation. The controller can handle different voltages and reacts fast to changes in load. You can build circuits for renewable energy, computer hardware, or industrial power supplies. The SG3525 lowers the number of extra parts you need:
-
It has a built-in voltage reference.
-
The error amplifier uses the reference voltage.
-
The oscillator only needs a resistor and capacitor.
-
The soft-start just needs a timing capacitor.
-
Protection features like undervoltage lockout and PWM latch are inside.
-
The output stage can drive power transistors directly.
These features make your circuit simpler and better. You save space and make your designs more reliable.
SG3525A Equivalents
Equivalent ICs
Sometimes you need to swap out the SG3525A in your project. There are many other ICs that work in a similar way. These can be used instead of the SG3525A. The table below shows some popular choices. You can use this table to quickly see the different models and who makes them.
| Equivalent IC Model | Manufacturer | Description Summary |
|---|---|---|
| UC3525AQTRG3 | Texas Instruments | 0.5A switching controller, max 500kHz switching freq |
| UC2525ADWTRG4 | Texas Instruments | Regulating pulse width modulator, 16-SOIC package |
| SG3525AP | STMicroelectronics | Voltage mode PWM controller |
| SG3525ADW | Motorola Mobility LLC | 0.5A switching controller, max 400kHz switching freq |
| UC2525AQTR | Texas Instruments | 0.5A switching controller, max 500kHz switching freq |
| UC3525AQTR | Texas Instruments | 0.5A switching controller, max 400kHz switching freq |
| UC2525BQ | Unitrode Corporation | Voltage-mode switching controller, 0.5A, max 500kHz |
| UC3525BDW | Texas Instruments | Enhanced 35V, dual 0.4A 400kHz PWM controller |
| UC3525BDWTRG4 | Texas Instruments | Regulating pulse width modulator, 16-SOIC package |
| UC2525BQTR | Texas Instruments | 0.5A switching controller, max 500kHz switching freq |
You can use any of these ICs as a sg3525a equivalent in lots of projects.
Comparison
It is important to check the features and pinouts before you pick a replacement. The next table shows how the SG3525A compares to the KA3525A and SG1525A. Both the KA3525A and SG1525A can be used instead of the SG3525A.
| Feature / Aspect | SG3525A PWM Controller | KA3525A | SG1525A |
|---|---|---|---|
| Functionality | PWM control, adjustable frequency, output current limiting, short circuit protection, soft start, dead time control, undervoltage lockout, synchronization, internal error amplifier | Direct substitute for SG3525A, similar features and pinouts | Not explicitly described |
| Applications | Power supplies, motor speed control, battery chargers, UPS, lighting, industrial automation, power factor correction | Similar applications implied | N/A |
| Pinout Comparison | Detailed pinout available (DIP16 package) | No detailed pinout comparison provided | N/A |
| Additional Notes | Improved performance, low cost | Direct substitute with similar functionality | N/A |
The KA3525A is almost the same as the SG3525A. The SG1525A is also used for similar jobs. You should always check the datasheet to be sure.
Selection Tips
When you choose a replacement, look at a few things. First, check who makes the IC. Some brands may have small changes in how the IC works or looks. Next, compare the features and pinouts by reading datasheets or using online tools. You should also look at example circuits and notes from the company. These help you know if the new IC will work in your project. Always test the replacement in your own circuit before you use it for real.
Tip: For the best results, pick an IC with the same pinout and close electrical ratings. This helps you build your project more easily and safely.
SG3525 Applications
Power Supplies
The sg3525 works in lots of power supply projects. It can be used in Push-Pull and Half Bridge designs. These designs help make DC-DC converters and switching power supplies. The sg3525 has two PWM outputs for better control. You can use it to control voltage and current very well. Many engineers pick this IC for computer power supplies and battery chargers. It is also used in industrial machines. You will see the sg3525 in home UPS and solar power systems. Its built-in features mean you need fewer extra parts. This makes your design easier and more dependable.
The sg3525 helps you build power supplies that save energy and stay steady for many uses.
Inverters
The sg3525 is used in inverters for homes and factories. You can use it to make DC-AC inverters for solar panels or backup power. The Push-Pull design is popular because it uses both outputs of the sg3525. This lets you drive two switches for better voltage control. It also helps the inverter work more efficiently. The sg3525 is found in TV power boards too. Many solar inverters and battery chargers use this IC because it works well and is simple to set up.
-
Some common sg3525 inverter uses:
-
Solar inverters
-
Home UPS
-
Factory backup systems
-
Motor Control
The sg3525 can control motor speed in many machines. You can change the frequency and duty cycle to set the motor speed. The sg3525 has two output drivers and dead-time control. These features help keep your motor safe from harm. You will find this IC in both factory and home motor controllers. It keeps the system safe by limiting current and using soft-start. These protections make the sg3525 a good pick for safe motor control.
Other Uses
The sg3525a is used for more than just power supplies and inverters. You can use it in heater controllers to manage power to heating coils. For example, a PWM heater controller uses the sg3525 with a sensor and MOSFET. This setup gives just the right amount of power. It saves energy and keeps your equipment safe. The sg3525 is also used in thermoelectric coolers and other power circuits. These uses show that the sg3525 is flexible and helpful in many real projects.
You can count on the sg3525 for many jobs, from power control to keeping temperatures just right.
You can trust the SG3525A to control power well and safely. It changes energy with little waste and lets you pick the best frequency. It also has safety features built in.
-
In real projects, it can work at over 90% efficiency.
-
The strong design and simple pin layout help you make circuits that do not fail.
If you read the datasheet and learn what each pin does, you can use soft start and shutdown to keep things safe.
Here are some main things to know:
| Feature | Benefit |
|---|---|
| High reliability | Works well for a long time |
| Flexible control | Lets you change your design |
| Built-in safety | Keeps your circuit from harm |
You should think about using the SG3525A or similar chips for your next PWM project. Newer controllers will use these good features to make your designs even stronger.
FAQ
What is the main function of the SG3525A?
You use the SG3525A to control the width of pulses in power circuits. This helps you manage voltage and current in devices like power supplies, inverters, and battery chargers.
Can I use the SG3525A for both AC and DC circuits?
You use the SG3525A mainly in DC circuits. It works best in DC-DC converters and DC-AC inverters. You should not use it directly with AC mains without extra safety circuits.
How do I set the frequency on the SG3525A?
You set the frequency by choosing the right resistor (RT) and capacitor (CT) values. The datasheet gives you formulas and example values. Try different parts to match your project’s needs.
What should I do if the SG3525A gets hot?
Always check your wiring and load. Make sure you do not exceed the voltage or current limits. Add a heatsink or improve airflow if needed. Double-check your circuit for short circuits or wrong connections.
Written by Jack Elliott from AIChipLink.
AIChipLink, one of the fastest-growing global independent electronic components distributors in the world, offers millions of products from thousands of manufacturers, and many of our in-stock parts is available to ship same day.
We mainly source and distribute integrated circuit (IC) products of brands such as Broadcom, Microchip, Texas Instruments, Infineon, NXP, Analog Devices, Qualcomm, Intel, etc., which are widely used in communication & network, telecom, industrial control, new energy and automotive electronics.
Empowered by AI, Linked to the Future. Get started on AIChipLink.com and submit your RFQ online today!
