MT3608 Converter Manufacturer, Working Principle and Applications
11 January 2024
Ⅱ. Who is the manufacturer of MT3608?
Ⅳ. MT3608 symbol, footprint and pin configuration
Ⅴ. What are the advantages and disadvantages of MT3608?
Ⅵ. Working principle of MT3608
Ⅶ. Can the MT3608 boost circuit be connected in series?
Ⅷ. Application fields of MT3608
MT3608 is a 6-pin SOT 23 current mode step converter with constant frequency. The chip uses an internal power switch and an efficient pulse width modulation control circuit to achieve a conversion efficiency of up to 96 percent. It also has various protection functions such as overvoltage protection and overtemperature protection, making it very suitable for use in electronic equipment. In this article, we will introduce the specifications and performance of MT3608.
MT3608 is a high efficiency boost converter. It can increase low voltage to higher voltage and is suitable for parts of electronic products that require high voltage, such as electronic clocks, LED lights, and battery charging. The MT3608's switching frequency is 1.2MHz, allowing the use of small, low-cost capacitors and inductors with a height of no more than 2mm. Internal soft-start produces less inrush current and extends battery life. MT3608 has the function of automatically switching to pulse frequency modulation mode under light load. The MT3608 includes undervoltage lockout, current limit, and thermal overload protection to prevent damage in the event of an output overload. It integrates an 80 milliohm power tube inside, and the maximum voltage can reach 48V. The maximum current can reach 4A.
Alternatives and equivalents:
• MT36291
• SX1308
The manufacturer of MT3608 is Aerosemi. Founded in February 2011, Aerosemi is a company specializing in the production of high-quality chips and electronic components. The brand's products have been widely used in many fields in China and have greatly contributed to the development of China's semiconductor industry. The company focuses on developing serialized power management chip products such as smart home and IoT chips, LED green lighting driver chips, power battery management system for new energy vehicles, power battery charging management chips, motor management system chips, high and low voltage DC/DC, AC/DC converters, and so on.
• MT3608 is manufactured by Aerosemi.
• It has one output channel.
• Its input voltage is 2V to 24V.
• Its output voltage is up to 28V.
• It has a fixed switching frequency of 1.2MHz.
• It has 6 pins and comes in SOT-23 package and Tape & Reel (TR) packaging.
• It belongs to the integrated circuit category.
The symbol, footprint and pin configuration of MT3608 are shown in the figure above. Among them, it has a total of 6 pins and is packaged in SOT-23 and Tape & Reel (TR). Its pin names and descriptions are as follows.
Pin 1 (SW): This is the power switch output. SW is the drain of the internal MOSFET switch. We connect the power inductor and output rectifier to SW. SW can swing between GND and 28V.
Pin 2 (GND): This is the ground pin.
Pin 3 (FB): This is the feedback input. The FB voltage is 0.6V. We connect the resistor divider to FB.
Pin 4 (EN): This is the regulator on/off control input. When the high input at EN is turned on, the converter will turn on; when the low input is turned on, the converter will turn off. When not in use, we connect EN to the input power supply to automatically start it.
Pin 5 (IN): This is the input power pin and must be bypassed locally.
Pin 6 (NC): NC
1. The advantages of MT3608 are as follows:
(1) High reliability and low cost: MT3608 adopts advanced production technology and strict quality control, which greatly improves its performance. In addition to high reliability, it also has the advantage of low cost.
(2) High efficiency: Its conversion efficiency is as high as 96 percent, which can greatly reduce energy loss and improve energy utilization efficiency.
(3) Complete protection functions: It has multiple protection functions such as over-voltage protection and over-temperature protection, providing comprehensive safety protection for electronic equipment.
(4) With boost function: MT3608 is a high-efficiency DC-DC converter that can boost low voltage to higher voltage and provide high-voltage power supply for various electronic products. For example, it is widely used in fields that require high voltage parts such as LED lights, battery charging, and electronic clocks.
2. The disadvantages of MT3608 are as follows:
(1) External components are required: When using MT3608, in order to ensure the best performance and stability, it may require some specific external components, such as capacitors, inductors, etc. These additional components need to be purchased and installed by the user, which also increases the cost of use.
(2) Poor adaptability to power supply: If the input voltage fluctuates greatly, it may affect the stability of the output voltage.
(3) High requirements for the working environment: MT3608 needs to work in a dry and well-ventilated environment to avoid the impact of moisture and high temperature on chip performance.
(4) High technical requirements: Since the chip has high technical requirements, it may be difficult for some users with limited technical capabilities.
The MT3608 uses a fixed frequency, peak current mode boost regulator architecture to regulate the voltage at the feedback pin. The block diagram of MT3608 can understand the operation of MT3608. At the beginning of each oscillator cycle, the MOSFET is turned on via the control circuit. To prevent subharmonic oscillations with duty cycles greater than 50 percent, we add a stabilizing ramp to the output of the current sense amplifier and feed the result to the negative input of the PWM comparator. When this voltage equals the output voltage of the error amplifier, the power MOSFET is turned off. The voltage at the error amplifier output is an amplified version of the difference between the 0.6V bandgap reference voltage and the feedback voltage. This way, the peak current level keeps the output in regulation. If the feedback voltage begins to decrease, the output of the error amplifier increases. These will cause more current to pass through the power MOSFET, thereby increasing the power delivered to the output. The MT3608 has an internal soft-start to limit the amount of input current at startup and limit the amount of overshoot on the output.
MT3608 can be connected in series. When connecting MT3608 in series, we need to pay attention to the following points:
The first is stability. When connecting MT3608 in series, we need to pay attention to the stability of the entire circuit. Generally speaking, the stability of the circuit is related to the quality of the inductor and capacitor. Therefore, when selecting components, we must choose components with good quality and stable performance.
Next is efficiency and power. Connecting multiple MT3608 modules in series will reduce the efficiency of the entire circuit. Because each module will have a certain energy loss, and the energy loss will increase as the number of modules connected in series increases. When calculating power, we need to consider the maximum power of the entire circuit and the rated power of each module.
Additionally, we need to pay attention to its input voltage. The input voltage of each MT3608 module must be lower than its output voltage. Because if the input voltage is higher than the output voltage, the chip will not work properly and may even be damaged.
Finally, we need to pay attention to how it is controlled. Since the output voltage of each MT3608 module can be adjusted by adjusting the inductor and capacitor, when connected in series, we need to set the output voltage of the previous MT3608 to the input voltage of the next MT3608, so as to ensure that each module can normal work.
MT3608 is often used in the following fields:
• Medical equipment: In the medical field, portable medical equipment is increasingly used. These equipment include blood pressure monitors, thermometers, portable ultrasound, etc. In these portable medical equipment, the MT3608 chip is used to ensure stable power supply for the equipment.
• Wireless communication equipment: In some wireless communication equipment, MT3608 can be used to provide the required power to the radio frequency (RF) module.
• Power module: MT3608 can be used as part of a power module to provide stable power supply and is suitable for various electronic systems and embedded applications.
• LED driver: MT3608 can be used as an LED driver to provide the required voltage and current through boost conversion to drive LED lighting systems.
• Solar charger: Since MT3608 can convert low voltage to the required higher voltage, it is also used in solar chargers. It can effectively manage the low voltage output from solar panels.
Frequently Asked Questions
1. What is the switching frequency of MT3608?
The MT3608 Step Up Regulator has a switching frequency of 1.2 Mhz.
2. Can I use two boost converters?
Yes, it is possible to use two DC-DC boost converters in series from separate DC sources. This configuration allows you to step up the voltage from the first converter and then further increase it using the second converter.
3. What is the output power of the MT3608?
The MT3608 Mini Adjustable DC-DC Boost Module is a low cost module that can step-up a 2.5 to 24V input voltage up to a 5 to 28V output at up to 1.5A.
4. What does an MT3608 do?
The MT3608 features automatic shifting to pulse frequency modulation mode at light loads. It includes under-voltage lockout, current limiting, and thermal overload protection. This module has a multi-turn trimpot (potentiometer) that you can use to adjust the output voltage.
5. How to use MT3608 boost converter?
Connect the converter with the battery or other power source. Set the multimeter to read the voltage and connect the output of the converter to it. Now you can already see the voltage on the output. Adjust the trimmer (here 100k Ohm) with a tiny screwdriver until the voltage is set to the desired output.
