ME2188 

ME2188A50XG 

Efficient PFM synchronous boost DC-DC conversion chip Overview ME2188 is a series of high conversion efficiency, low power consumption, and high operating frequency PFM synchronous boost DC-DC conversion chip. Chip utilizes PFM control Circuit, automatically switching duty cycle coefficient based on load current, can achieve low A series of products with ripple, high efficiency, and wide output voltage range. Chip built-in The low consumption current of synchronous switch tubes and chips effectively improves DC-DC Conversion efficiency and equipment usage cycle. Only three components are needed on the periphery It can boost the low input battery voltage to the required working voltage. characteristic ● High efficiency: 93% Low startup voltage: 0.9V @ IOUT=1mA Low static current: 7uA Frequency: 320KHz Optional output voltage: 1.9V~5.0V Output accuracy: ± 2% Output current: 300mA Low ripple and low noise ● Synchronous rectification Application Packaging Form ● Electronic equipment with 1-2 dry batteries ● 5-pin SOT23-5 ● Digital camera, LED flashlight, LED light, blood pressure monitor, ● 3-pin SOT23, SOT23-3, SOT89-3, TO92 Remote control toys, wireless headphones, wireless mouse and keyboard, medical devices Handheld electronic devices such as car anti-theft devices, chargers, VCRs, PDAs, etc Selection and precautions of external devices: The peripheral circuit has a significant impact on the performance of ME2188, and it is necessary to choose external devices reasonably: The external capacitance value should not be less than 40 μ F (too small a capacitance value will cause excessive output ripple), while also having good frequency characteristics (preferably using tantalum capacitors). transport If the output capacitance is too large, it will slow down the reaction time of the system and increase the cost. So it is recommended to use a 47uF capacitor. If smaller ripple is required Greater capacitance is required. If the load is small (about 10mA), a smaller capacitor can be used. When under heavy load, the ripple caused by ESR will As the main factor, ESR increases efficiency loss and reduces conversion efficiency. So it is recommended to use tantalum capacitors with low ESR or multiple capacitors Parallel use. The external inductance value should be small enough to store enough energy even at the lowest input voltage and the shortest LX switching time, while the inductance value should be sufficient Enough to prevent ILXMAX from exceeding the maximum rated value at the highest input voltage and the longest LX switching time. In addition, the DC impedance of the external inductor should be small and the capacitance should be small The value should be high and not reach magnetic saturation during operation. PCBLayout precautions: The smaller the distance between external components and chips, the better, and the shorter the wiring, the better. Especially for components connected to the VOUT terminal, the length of the connection with the capacitor should be minimized as much as possible; It is recommended to connect a 0.1 µ F ceramic capacitor at both ends of the chip VOUT and GND. The GND end should be fully grounded, otherwise the zero potential inside the chip will vary with the switching current And changes cause unstable working conditions The content of this information may be subject to unannounced changes as the product improves. Our company shall not be responsible for any issues arising from the industrial ownership of third parties, such as the design drawings recorded in this document. Additionally, The application circuit example is a representative application description of the product, not a design that guarantees mass production. The content of this material is strictly prohibited from being reprinted or copied for other purposes without the permission of our company. The products recorded in this document shall not be used as health devices, medical devices, disaster prevention devices, or tiles without the written permission of our company The use of devices or device components that have an impact on the human body, such as related equipment, vehicle equipment, aviation equipment, and vehicular equipment. Although our company has always been committed to improving quality and reliability, semiconductor products may fail with a certain probability Incorrect operation. To prevent personal accidents, fire accidents, social damage, etc. caused by malfunctions or incorrect actions, please fully reserve Safety design such as heart redundancy design, fire spread countermeasure design, and error prevention design