SJ1117-3 Common low-pressure differential three-terminal stabilityPressure chip (LDO), fixed value 3V voltage regulator output, output 800~1000mA.
This voltage regulator chip is a step-down voltage regulator power supply, and the input must be higher than the output voltage to work normally. If the load current is not large, the parallel voltage regulator can be consideredWhat chip is used to turn the single chip microcomputer 3.3V!
1, the highest efficiency is DCDC. STM32F series belongs to the low-end 32-bit ARM microcontroller 3.3vldo voltage regulator , this series of chips is stmicroelectronics (ST) company 3.3vldo voltage regulator , its core is Cortex-M3. This series of chips can be divided into three categories according to the size of the on-chip Flash: small capacity (16K and 32K), medium capacity (64K and 128K), large capacity (256K, 384K and 512K).
2, MCU and peripheral chips are generally CMOS, the power supply voltage adaptation range is very wide, 3.3vldo voltage regulator chip What reason do you have to 3V work, say more details, perhaps there are other solutions. And the voltage regulator is certainly not possible, the voltage regulator in front of the series to adjust the resistance, it is not as good as the low voltage difference regulator block.
3, charging can use TP405 TP4057 USB to power single-chip microcomputer can use LMS1585 butIt is more troublesome for your lithium battery to supply power to the MCU, because the lithium battery is fully charged to 2V, and it can be 7V when the power is low, so it can not directly supply power to the MCU, but the general buck IC can not work under such a low voltage difference. It is recommended to use LM2577 to boost the voltage before using LMS1585 to buck the MCU. Call me if you need the circuit.