A variety of AMC34063 mobile phone charging board use (with circuit diagram)

Mobile phone crystal 3.2*2.5mm 3225 26M (26.000MHZ)

The mobile phone charging board described in this paper is a low-voltage switching power supply composed of integrated circuit AMC34063, which is an energy-efficient circuit (see Figure 1). When the circuit is unloaded and the input voltage is 3~40V, its current consumption is only 4mA. If the circuit component value is slightly modified, it can be a variety of charging and power supply of the step-down type. By substituting the component values ​​in Table 1 into Figure 2, several common output voltages corresponding to those in Table 1 can be obtained. The conversion efficiency of the buck-type pulse switching power supply circuit can reach 80%. In addition, the circuit and component values ​​can be slightly modified on the original circuit board to become a pulse-boost switching circuit. By substituting the component values ​​of Table 2 into the boosting circuit of Figure 3, several common boost outputs corresponding to Table 2 can be obtained to suit various needs. The boost circuit has a conversion efficiency of up to 90%.

In Figure 2, the output currents of the various voltages are all designed to a maximum current of 0.75A. In Figure 3, the maximum currents of the various output voltages are completely different and are clearly labeled in Table 2. In the boost circuit of Figure 3, a 180Ω resistor is added between pins 7-8. The withstand voltage values ​​of the electrolytic capacitors of C1 and C3 in Figs. 2 and 3 are selected according to the values ​​of the input/output voltages. Since the two circuits of Figure 2 and Figure 3 are designed according to the maximum output current, the current limiting resistor R1 is 0.2 Ω uniformly. C2 is selected according to the circuit operating frequency of 60 kHz to 10 DkHz. The output filter electrolytic capacity is 10 mV according to the output ripple. If selected, the electrolytic capacity can be increased if there is a higher requirement. In addition, the inductor L1 selects the ring-shaped high-current inductor on the original circuit. If used for charging, it can retain the original 170μH inductance. If it is used for power supply, the inductor can be removed after 35匝 (70匝 total), and the inductance after 35匝 is removed. It is 42 μH.