DC/DC conversion circuit made with six inverters

The circuit as shown in the figure can use a TTL six-phase inverter to form a DC/DC converter to convert 5V into 12V. This circuit provides all the functions required for DC/DC conversion.

This circuit relies on TTL switching thresholds to regulate the voltage. U1A and U1B form an oscillator with a switching frequency of <1MHz. The output of the oscillator drives three parallel inverters U1C, U1D and U1E, which can provide higher output current and output power. Its internal output transistor, L1 and D1 form a standard boost converter. When its output is low, current only flows through the inductor L1; when its output goes high, the energy stored in the inductor forces the anode of D1 to go high, D1 is turned on to charge C1.

U1F monitors the divided voltage of the output voltage on the feedback resistors R1 and R2. When the voltage at both ends of C1 exceeds 12V, the input of U1F exceeds the TTL logic threshold (about 1.2V), and the output of U1F becomes low, prohibiting the voltage from continuing to rise; when the output voltage When falling below 1.2V, U1F turns off again allowing the oscillator to drive the switching power supply.

The line and load characteristics of this circuit are better than 1%, and the output voltage changes only 7% in the range of 0℃~50℃.

It is required to use an open-collector 7406 six-phase inverter. The inverter can output 30V and 40mA, so three parallel connections can drive a switching peak current of 120mA.