Simple LED Driver Circuit using IC CAT3063

A simple but super effective LED driver circuit uses a special chip called the CAT3063 which is really important for powering LEDs efficiently.

This circuit helps keep the LEDs working well and can also make them last longer.

In this post, we will explore how the LED driver circuit works with the CAT3063 chip which is made to provide a steady current to several LEDs.

The CAT3063 is great because it can efficiently power up to three LEDs at the same time.

However, it is important to remember that the CAT3063 should only be used with LEDs and not with other types of loads since it is specifically designed for LED use.

The power supply voltage must stay below 6 volts DC, we have used 5V DC power supply in our circuit.

The maximum output current should be no more than 120 milliamps.

Circuit Working:

Parts List:

The circuit uses the CAT3063 LED driver chip, which carefully controls the current going to the LEDs.

This chip needs a direct current DC voltage input VIN to power its internal parts.

To keep the voltage steady and efficient for the internal charge pump capacitors C1 and C2 are included in the design.

When the circuit is turned on the enable pin EN is activated allowing the chip to supply a steady and controlled current to the LEDs.

The RESET pin connected to a resistor R1 is important for starting the circuit correctly.

The LEDs (LED1, LED2, and LED3) are set up in parallel with the output pins of the chip, which helps them shine evenly.

Additionally, capacitor C3 is used to reduce any voltage changes at the output ensuring the LEDs work smoothly.

In shutdown mode the current drops to almost zero which is great for saving energy.

With the chosen value of R1 the current through each LED channel is set to 25mA.

To dim the LEDs you can either change the current at pin 4 RESET with a direct current voltage or use a pulse width modulation PWM signal to control the enable pin EN at pin 5.

Formulas with Calculations:

LED Current Calculation:

Formulas with calculations are mentioned below if you are using to design Simple LED Driver Circuit using IC CAT3063 for better understanding:

The CAT3063 provides a constant current per output.

The current is typically 20mA per LED output and does not require an external resistor for regulation.

The formula to calculate LED current is:

I_LED = (V_OUT – V_F) / R_SET

where,

• I_LED is the current through each LED around 20mA
• V_OUT is the output voltage of the IC
• V_F is the forward voltage of the LED around 3V for white LEDs
• R_SET is the internal resistance in the IC

Since the IC is factory set no external resistor is needed.

Power Dissipation Calculation:

The total power dissipation of the circuit can be calculated using:

P_TOTAL = V_OUT × I_TOTAL

where,

• P_TOTAL is the total power dissipation
• V_OUT is the output voltage from the IC
• I_TOTAL is the total current supplied to all LEDs

For 3 LEDs each drawing 20mA:

I_TOTAL = 3 × 20mA = 60mA

If V_OUT is 5V then:

P_TOTAL = 5V × 60mA = 0.3W

How to Build:

To build a Simple LED Driver Circuit using IC CAT3063 follow the below mentioned steps for connections:

• Gather all the components mentioned in the above circuit diagram
• Connect pin 1 LED1 of IC1 CAT3063 to pin 6 of IC1
• Connect pin 2 LED2 of IC1 CAT3063 to pin 6 of IC1
• Connect pin 3 LED3 of IC1 CAT3063 to pin 6 of IC1
• Connect capacitor C3 from pin 6 of IC1 and GND.
• Connect pin 4 RESET pin to GND through resistor R1
• Pin 5 EN (Enable) pin turns the IC ON/OFF
• Connect pin 7 of IC1 to VIN pin.
• Connect capacitor C4 from pin 7 and GND
• Connect one end of capacitor C1 from pin 8 C1+ and other end of C1 connect to pin 9 C1-
• Connect one end of capacitor C2 from pin 10 C2+ and other end of C1 connect to pin 11 C2-
• Connect pin 12 of IC1 to GND

Conclusion:

This Simple LED Driver Circuit using IC CAT3063 is really efficient and keeps the LEDs working steadily by providing a constant current.

One cool thing about this design is that it does not require extra resistors to control the current, which makes it perfect for small and battery powered LED projects.

Overall, this circuit is a easy and dependable way to power LEDs with just a few parts.

References:

CAT3063 3-Channel LED Driver in 3 x 3 mm Package