MCU and peripheral chips are generally CMOS, the power supply voltage adaptation range is very wide, you have any reason to be 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.
The most efficient is DCDC. STM32F series belongs to the low-end 32-bit ARM microcontroller, the series chip is produced by stmicroelectronics (ST) company, its core isCortex-M3.
Use a lithium battery to output a stable 3V voltage, you can choose a BL8505-3 chip. BL8505-3 is a DC-DC conversion circuit with BOOST structure and voltage type PFM control mode.
USB can use LMS1585 to power the MCU, but your lithium battery to power the MCU is more troublesome, because the lithium battery is fully charged to 2V, and the power can be 7V when the power is low, so it can not directly supply the MCU, but the general step-down IC can not work under such a low voltage difference.
1, LDO is a linear voltage regulator. Linear regulators use transistors or FETs operating in their linear region to subtract the excess voltage from the input voltage to produce a regulated output voltage.
2, if the output current is less than 1A, HB3106 can be used. Input voltage 75-40V, withstand voltage 45V, output voltage is adjustable. The periphery is simple.
3, the V voltage is generally used to power the cpu, and the ripple requirement is relatively small.
4. High voltage buck DC-DC MAX50XX or LM50XX MAX5035 Wide input voltage range: 5V to 76V, providing up to 1A output current. The maximum heat dissipation capacity of the package limits the output current. External turn-off mode is available with 10A (typical) turn-off current.
5, MCU and peripheral chips are generally CMOS, the power supply voltage adaptation range is very wide, you have what reason must be 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.
1, this is 3v regulator IC, commonly known as ldo, LDO (low voltage difference linear voltage regulator chip AMS1117) use, and the first half of the separate chip similar, AMS1117 also has a fixed output and adjustable output model distinction, the use of 3V fixed voltage output. Add: AMS1117 and LM1117 no difference, only the manufacturer is different.
2, the use of lithium battery output stabilityThe 3V voltage can be selected from a BL8505-3 chip. BL8505-3 is a DC-DC conversion circuit with BOOST structure and voltage type PFM control mode.
3, the chip reads the voltage, generally through the ADC to achieve, STM32 has an internal ADC device, that is, through the analog IO port (this IO port is required to be configured) to read the IO voltage, and then converted into a digital amount, so read to the chip, essentially read to the firmware code you write.
4, series, spx1117 series, TAR5S series low power regulator IC, LM1117-3, XC6206-33, Mic5207, AP432, APL117-3, AS1118-3 ROHM BA033, with 7805 wiring, low voltage drop, there are a variety of packages.
5, directly use the switch type decompression chip LM2576, the output can reach 3A, which may be hot. Many voltage regulator chips with 3V output can be ASM1117-3, LD1117-3 or LD1117-ADJ. Best divided into two stages of pressure first to 6V, you can use 7806 plusThe heat sink, then to 3V, may be very small heat.
6, the three-terminal voltage regulator integrated circuit commonly seen in electronic products has 78×× series of positive voltage output and 79×× series of negative voltage output. Therefore, the name means that the three-terminal IC means that the integrated circuit used for voltage regulation has only three pin outputs, which are the input end, the ground end and the output end.
1, no, to be clear, most of the 1117 can achieve 25V starting voltage, BM1117 is very low and can only achieve 0.8V pressure difference, it is recommended that you use BM7533, the pressure difference can achieve 0.1V, 100mA output.
2, AiP1117-3 TO-252 is a linear regulator with a voltage regulator function, which can stabilize the input voltage and output 3V voltage. It is a chip in the TO-252 package, also known as the SOT-223 package.
V, and inversely proportional to the load current, can not be stabilized or even no output.
5, [1] 1117-3 belongs to the series voltage regulator power supply. The higher the input voltage, the greater the power P= (Vin-3) * I carried by the device itself. Therefore, the lower the input voltage, the better. If the input voltage is 6V, the power consumption of the load is equal to that of the power supply, and the efficiency is 50%.