A DC-DC boost converter is a special type of circuit that raises the output voltage higher than the input voltage.
The LM2698 integrated circuit is a versatile boost converter featuring an internal switch that can handle up to 18V and 1.35A, with a resistance of 0.2 Ohm.
This design enables it to efficiently convert power, generating output voltages from 2.2V to 17V DC.
It can also take input voltages that fall within the same range of 2.2V to 17V DC.
This IC is well known for its ability to keep the voltage steady, no matter what the input voltage is.
The LM2698 is celebrated as a very efficient boost regulator that performs well with different input voltages, making it perfect for devices powered by batteries.
The Simple 12V Boost Converter Circuit using the LM2698 IC is made to change a 5V input into a 12V output.
It also explains how the circuit works, the calculations needed for the design and how to create a 12V boost converter with the LM2698 IC.
Circuit Working:
Parts List:
| Component Type | Value | Quantity |
|---|---|---|
| Resistors (1/4W) | 25k | 1 |
| 30k | 1 | |
| 3.5k | 1 | |
| Capacitors | Ceramic 4.7nF | 1 |
| Electrolytic 22µF 25V | 1 | |
| Electrolytic 10µF 25V | 1 | |
| Semiconductors | IC LM2698 | 1 |
| 1N5819 Schottky Diode | 1 | |
| Inductor | 10µH | 1 |
In this article the IC LM2698 is a special device called a switching regulator that boosts the input voltage to provide a steady output of 12V.
The analog power input pin 6 of the IC receives the input voltage, It works with input voltages between 4.5V and 5.5V DC.
It is really important not to connect anything that uses more than 400mA, because the chip can only give out a maximum of 400mA at 12V.
Inside the circuit, there is an inductor L1 that saves energy when the internal switch of the LM2698 is turned on.
When the switch turns off the stored energy is sent through a diode D1 to charge the output capacitor C3 keeping the output at a stable 12V.
Also, the feedback system made by resistors R2 and R3 is key to controlling the output voltage by adjusting how long the switch stays on.
If Pin 3 SHDN (shutdown) pin is connected to the ground it will turn off the circuit.
Formulas with Calculations:
The formulas with calculations are mentioned below to design your own Simple 12V Boost Converter Circuit using IC LM2698:
Output Voltage Calculation:
Vout = 1.26V * (1 + R2 / R3)
where,
- Vout represents the output voltage
- 1.26V IC has an internal reference voltage
- R2, R3 are the resistors that form a voltage divider
Substituting values R2 = 30k and R3 = 3.5k
Vout = 1.26V * (1 + 30000 / 3500)
Vout = 1.26V * (1 + 8.57)
Vout = 1.26V * 9.57
Vout = 12V
How to Build:
To build a Simple 12V Boost Converter Circuit using IC LM2698 following steps are required to follow the connections:
- Gather all the components as mentioned in the above circuit diagram
- Connect pin 1 of IC1 to GND through resistor R1 and capacitor C1
- Connect pin 2 of IC1 to Vout of 12V DC through resistor R2
- Connect resistor R2 from pin 2 of IC1 and GND
- Pin 3 is the shutdown pin if connected to the ground will shutdown the circuit
- Connect pin 4 and pin 7 of IC1 to GND
- Connect L1 inductor coil between pin 5 and pin 6 of IC1
- Connect capacitor C2 from pin 6 of IC1 and GND
- Connect diode D1 between pin 5 of IC1 and other terminal of resistor R2
- Connect Vin 4.5V to 5.5V to the junction of pin 6, L1 inductor coil and positive of capacitor C2
- Connect capacitor C3 positive to one terminal of resistor R2 and negative of capacitor C3 connect to GND
Conclusion:
The Simple 12V Boost Converter Circuit using IC LM2698 is a smart step-up converter designed for low voltage input uses.
By choosing the right parts this circuit can deliver a steady 12V output for different electronic projects.
The LM2698 is known for its high efficiency and simple setup, which makes it perfect for devices powered by batteries and other power management needs.