Introduction
The MC34063 is one of the most widely used DC-DC switching regulator ICs for building boost, buck, and inverting converter circuits. Due to its low cost, easy availability, and minimal external component requirements, it remains a popular choice among electronics enthusiasts, students, and engineers.
In this project, we will discuss a boost converter circuit using the MC34063 IC that converts a 5V DC input into approximately 10V DC output. The IC contains an internal switching transistor, oscillator, comparator, reference voltage source, and current limiting circuitry, making it ideal for compact DC-DC converter applications.
What is a Boost Converter?
A boost converter is a DC-DC power converter that increases a lower input voltage to a higher output voltage. It works by storing energy in an inductor during the switching cycle and then releasing that energy to the load at a higher voltage level.
For example:
- 5V to 10V
- 5V to 12V
- 3.7V to 9V
Boost converters are commonly used in battery-powered devices, portable electronics, LED drivers, and microcontroller projects.
MC34063 IC Overview
The MC34063 is a versatile switching regulator IC capable of operating as:
- Boost Converter
- Buck Converter
- Inverting Converter
Internal Features
- Built-in oscillator
- Internal switching transistor
- Precision voltage reference
- Current limiting protection
- Comparator for voltage regulation
- Driver circuitry
These features reduce circuit complexity and component count.
MC34063 Pinout
The MC34063AP IC consists of eight pins.
| Pin No. | Pin Name | Function |
|---|---|---|
| 1 | Switch Collector | Internal transistor collector |
| 2 | Switch Emitter | Internal transistor emitter |
| 3 | Timing Capacitor | Sets switching frequency |
| 4 | Ground (GND) | Ground connection |
| 5 | Comparator Inverting Input | Feedback voltage input |
| 6 | VCC | Input supply voltage |
| 7 | Ipk Sense | Peak current sensing |
| 8 | Driver Collector | Driver transistor collector |
Components Required
The following components are required to build the boost converter circuit.
| Component | Value |
|---|---|
| IC | MC34063AP |
| Schottky Diode | 1N5819 |
| Inductor | 33µH |
| Electrolytic Capacitor | 100µF × 2 |
| Ceramic Capacitor | 270pF |
| Resistors | 0.3Ω, 180Ω, 1KΩ, 6.8KΩ |
| Power Supply | 5V DC |
Circuit Operation
The boost converter works using the principle of energy storage in an inductor.
Switching ON State
When the internal transistor inside the MC34063 turns ON:
- Current flows through the inductor.
- Energy is stored in the magnetic field.
- The Schottky diode remains reverse-biased.
- The output capacitor powers the load.
Switching OFF State
When the transistor turns OFF:
- The magnetic field collapses.
- The stored energy is released.
- The inductor voltage combines with the input voltage.
- Current flows through the diode.
- The output capacitor charges to a voltage higher than the input voltage.
This process occurs continuously at high frequency, resulting in a stable boosted output voltage.
Voltage Regulation
The output voltage is monitored through a feedback resistor network connected to the comparator input.
The MC34063 continuously:
- Monitors output voltage
- Adjusts switching duty cycle
- Maintains voltage stability
- Compensates for load variations
This feedback mechanism ensures reliable and efficient operation.
Advantages of MC34063 Boost Converter
Low Cost
The MC34063 is one of the most affordable switching regulator ICs available.
High Efficiency
Switching regulation wastes less power than linear regulators.
Compact Design
Requires very few external components.
Versatile Operation
Can be configured as:
- Step-Up Converter
- Step-Down Converter
- Inverting Converter
Built-In Protection
Includes internal current limiting for enhanced safety.
Applications of MC34063 Boost Converter
This circuit can be used in various electronic applications including:
Microcontroller Projects
- Arduino circuits
- PIC microcontrollers
- AVR projects
- ESP32 systems
Battery-Powered Devices
- Portable electronics
- Rechargeable battery systems
- Power banks
LED Drivers
Provides higher voltage for LED strings and displays.
Sensor and Actuator Systems
Useful for powering sensors and output actuators requiring voltages higher than the available supply.
Portable Power Supplies
Ideal for compact voltage-boosting applications.
Frequently Asked Questions (FAQ)
What is the function of the MC34063 IC?
The MC34063 is a switching regulator IC used to build boost, buck, and inverting DC-DC converter circuits.
What output voltage can this circuit provide?
This design boosts a 5V input supply to approximately 10V output.
Why is a Schottky diode used?
The 1N5819 Schottky diode provides low forward voltage drop and fast switching performance, improving efficiency.
Can the MC34063 be used as a buck converter?
Yes. The IC supports boost, buck, and inverting converter configurations.
Is the MC34063 suitable for beginners?
Yes. Its simple design and low component count make it an excellent learning platform for understanding DC-DC converters.
Conclusion
The MC34063 boost converter circuit is a simple, reliable, and cost-effective solution for increasing low DC voltages. By using only a few external components, it can efficiently convert a 5V supply into a higher output voltage suitable for many electronic applications.
Thanks to its built-in oscillator, switching transistor, comparator, and current limiting features, the MC34063 continues to be one of the most popular DC-DC converter ICs for hobbyists, students, and professional designers.