There are mainly the following methods for lithium battery voltage boosting:
Boosting method:
Using boost chip: this is the most common boosting method. The boost chip can raise the lower voltage of the lithium battery to the required higher voltage. For example, if you want to raise the 3.7V lithium battery voltage to 5V to supply power to the device, you can use the appropriate boost chip, such as KF2185 and so on. These chips have high conversion efficiency, can be stabilized in the case of input voltage changes in the output of the set boost voltage, the peripheral circuit is relatively simple, easy to design and use.
Adopting transformer and related circuits: Boost voltage is realized through the electromagnetic induction principle of transformer. The DC output of the lithium battery is first converted to AC, then the voltage is increased by the transformer, and finally the AC is rectified back to DC. This method may be used in some occasions with high voltage and power requirements, but the circuit design is relatively complex, large and costly.
Using charge pump: charge pump is a circuit that uses capacitors as energy storage elements to realize voltage conversion. It can multiply and raise the voltage of a lithium battery, for example, raising a voltage of 3.7V to a voltage of twice that or a higher multiple. Charge pump circuit has the advantages of higher efficiency, small size, low cost, suitable for some of the higher space and efficiency requirements of small electronic devices.
Bucking Methods:
Use buck chip: Buck chip is a special integrated circuit that converts higher voltage to lower voltage. For lithium batteries, the voltage around 3.7V is usually reduced to a lower voltage such as 3.3V, 1.8V to meet the power supply requirements of different electronic components. Common buck chips include AMS1117, XC6206 and so on. When choosing a buck chip, you need to select according to the output current, voltage difference, stability and other parameters.
Series resistance voltage divider: this method is to connect a resistor in series in the circuit, so that part of the voltage drops on the resistor, thus realizing the reduction of lithium battery voltage. However, the voltage reduction effect of this method is not very stable and will be affected by changes in load current, and the resistor will consume a certain amount of power, resulting in energy waste. Therefore, this method is usually only suitable for occasions that do not require high voltage accuracy and small load current.
Linear voltage regulator: Linear voltage regulator is a device that realizes stable voltage output by adjusting the conduction degree of transistor. It can stabilize the lithium battery voltage down to the required voltage value, with stable output voltage, low noise and other advantages. However, the efficiency of the linear regulator is low, and when the difference between the input and output voltages is large, there will be more energy loss, resulting in greater heat generation.
Post time: Sep-24-2024