One of the simplest types of switch-mode converter is a boost converter. As the name suggests, an input voltage is needed and it is boosted or increased. An inductor, a semiconductor switch, a diode, and a capacitor are what it consists of. A source for a periodic square wave is also required.

I. Working Principle

It is mandatory that you know how inductors, MOSFETs, diodes, and capacitors function in order to understand the operation of a boost converter.

With that experience, step by step, we can go through the operation of the boost converter.

Phase 1: 

Nothing occurs here. Minus one diode drop, the output capacitor is charged to the input voltage.

Phase 2:

It's time, now, to turn on the light. The source of our signal goes big, turning on the MOSFET. All the current is redirected via the inductor to the MOSFET. Remember that the output capacitor remains charged as the now back-biased diode does not discharge into it.

The power supply is not short-circuited instantly, Of course, as the inductor relatively slowly makes the current ramp-up. A magnetic field also accumulates around the inductor. Notice the voltage polarity that is applied through the inductor.

Phrase 3:

The MOSFET is switched off and the current is suddenly halted by the inductor. Maintaining steady current flow is the very essence of an inductor; it doesn't like abrupt current shifts. So the abrupt turning off of the current doesn't like it. It responds to this by producing a large voltage using the energy stored in the magnetic field with the opposite polarity of the voltage originally supplied to it to sustain the current flow.

If we ignore the rest of the circuit elements and consider only the symbols of polarity, we notice that the inductor now behaves in series with the supply voltage like a voltage source. This implies that the diode anode is now at a higher voltage than the cathode (remember, at the beginning, the cap was already charged to supply voltage) and is biased forward. The output capacitor is now charged to a higher voltage than before, meaning we have increased a low DC voltage to a higher one successfully.

II. Selection of the Right Boost Regulator ICs

We've all come across circumstances when designing electronic circuits where there is a need for a slightly higher voltage than can be given by the power supply. There is also a need for 12V from a 9V battery, or maybe 5V from a 3.7V lithium battery is needed for your application.

The solution is often referred to as a boost converter, which can transform DC low voltage to DC high voltage. It takes an input voltage and boosts or lifts it, as the name implies. It consists of an inductor, a switch (a MOSFET, probably), a diode, and a capacitor. A switching square wave that we can provide with a function generator or a 555 timer IC is also needed.

There is a Synchronous Boost Converter to improve the performance of the boost converter, in which the circuit construction remains the same, but the diode is replaced by a MOSFET to decrease the loss. So, let's make this article an opportunity to find out other than the iconic MCP16252, NCP3064, MC34063A, etc., some of the smallest, cheapest, and widely used boost regulator ICs available on the market If you want to try other regulators other than boost regulators, you can also find out how to pick the linear regulator IC.

1. HT7733 by HOLTEK 100mA

The HT7733 has an input voltage range of 0.7V - 0.9V and is a very modern, low-cost, single-chip, step-up (boost) regulator. This IC is made for modern-day lightweight apps with many kit choices.

This IC only comes with fixed voltage versions, so it is not possible to change the output voltage, it comes with a 100mA maximum current rating, so it is used for compact applications with low power. For different voltage choices, please refer to the datasheet on this IC. This IC has a 115KHz fixed switching frequency. This IC can achieve an efficiency of 80 percent with this (assuming limited load condition).

Other Features: Pulse frequency modulation (PFM) based driver circuit for low noise operation, Ultra-low supply current of 4uA, Low ripple and low noise, Low shutdown current: 0.5A & more.

Protection Features: Under-Voltage Lockout Protection, & Over-Temperature Protection.

Applications: PDA Driver, Portable communicators, Cameras, Battery-powered equipment & more.

2. TPS610992 by Texas Instruments

A very modern, low-cost, single-chip, synchronous step-up (boost) regulator with an input voltage range of 0.7V to 5.5V is the TPS610992. This IC is made for ultra-compact applications with a 1.23 mm x 0.88 mm WCSP(6) kit.

This IC's output voltage can be set to anywhere from 1.8V - 5.5V. This regulator can withstand currents up to 800mA continuously with a 0.25 ⁇ internal control MOSFET. For more information, please see the datasheet of this IC.

This IC has a 120KHz fixed switching frequency. This IC can achieve an efficiency of 95 percent with this (assuming light load condition). The efficiency drops to 74 percent with a maximum load of 800mA.

Other Features: True Disconnection During Shutdown Mode, 1-µa Quiescent Current Under Light Load Condition, Additional Down Mode, and Pass-Through operations for different applications & more.

Protection Features: over-temperature protection & Over Voltage Protection.

Applications: Memory LCD Bias, Optical Heart Rate Monitor LED Bias, Wearable Applications, Battery-Powered Systems & portable products.

3. SE3608 by Allegro Seaward Electronics

The ME2188 is a rather modern, low-cost, single-chip, step-up (boost) controller with a 2.5V - 6V input voltage range. This IC is made for modern-day lightweight apps with a SOP8 kit.

It is possible to change the output voltage of this IC to anywhere between 2.5 - 10V. This regulator will manage the output current of 2A continuously with a 70-m or 0.007-internal power MOSFET. For more information, please see the datasheet of this IC.

This IC has a 1.2MHz fixed switching frequency. This IC will achieve an efficiency of 93 percent with this (assuming limited load condition). The performance drops down to 85 percent with a maximum load of 2A.

Other Features: Internal Soft Start, 1uA Shutdown Current, Accurate Reference: 0.6V VREF & more.

Protection Features: Under-Voltage Lockout Protection, Over-Temperature Protection & Internal Soft Start.

Applications: A power source for battery-powered equipment, Li-Po Charger, Digital Cameras & Portable Products.

4. MC34167 by ON Semiconductor

A very modern, low-cost, single-chip, the configurable voltage regulator is the MC34167, which means it can be programmed as a configuration for the buck, boost, or invert. With a TO220 & D2PAK kit, this IC is made for high-power applications with an input voltage range of 2.5V - 40V.

This IC's output voltage can be set to anywhere from 1.5 - VIN. This regulator can accommodate an output current of 5A continuously with a 0.08-internal control MOSFET. For more information, please see the datasheet of this IC.

This IC has a 72 kHz fixed switching frequency. This IC will achieve an efficiency of 85 percent with this (assuming limited load condition). The performance drops down to 65 percent with a maximum load of 5A.

Other Features: Internal Resistor for Fixed %V Output, Precision 2% Reference, 0% to 95% Output Duty Cycle, & 36uA Current Draw at Standby Mode.

Protection Features: Under-Voltage Lockout with Hysteresis, Cycle−by−Cycle Current Limiting & Internal Thermal Shutdown Protection.

Applications: A power source for battery-powered equipment, Li-Po Charger, Digital Cameras & High-Power Applications.

5. LT8471 by Linear Technology

A very new, single-chip, synchronous boost regulator with an input voltage range of 2.6V - 50V is the LT8471. This IC is produced for very dual power applications with a 20-Lead TSSOP and 28-Lead QFN Kit.

It has two output channels, one can handle a maximum current of 2A, and the other can handle a maximum current of 500mA, as this is a special type of IC. A buck, boost, sepic, zeta, flyback, or dc/dc inverting converter may be the 2A primary channels. The 500mA skyhook channel produces boosted input voltage efficiently. The output channel voltage can be changed to between 4.5V and 50V for both.

The switching frequency of this IC can be changed to 1.55MHz - 2.0 MHz. It can achieve an efficiency of 95 percent with this (assuming limited load condition). The performance drops down to 75 percent with a maximum load of 2A.

Other Features: UVLO and OVLO Programmable on OV/UV Pin, Soft-Start Programmable for Each Channel, Fixed Frequency PWM (Set by RT Pin or Synchronized to External Clock), Anti-Phase Switching Reduces Input Ripple

Protection Features: Output Overvoltage Protection, Cycle-by-Cycle Overcurrent Protection, Thermal Shutdown & more.

Applications: Dual Rail Power for Signal Chain & Buck/Buck, Buck/Boost, Boost/Boost, Boost/Invert, Invert/Invert, Buck/Invert.