DC-DC circuit online calculator

1: Polarity reversal. 2: Step-up. 3: Step-down. Automatic calculation of peripheral component parameters for three typical circuits How to use: Just enter the parameters you want in the left middle box, and then click the "calculate and refresh circuit diagram" button, it can automatically give all relevant peripheral component parameters and the corresponding standard circuit drawings, so that the design dc— The dc circuit is intelligent and efficient. About warning: If the parameters you enter exceed the limit of 34063, it will automatically pop up a warning window to remind you to change them. Special input: To design a polarity reversal circuit, please add a minus sign in front of the input or output voltage number, such as -5v. This is a kind of integrated circuit used for dc-dc power conversion. It is widely used and is cheap and easy to buy. The polarity reversal efficiency is up to 65%, the boosting efficiency is up to 90%, and the step-down efficiency is up to 80%. The conversion efficiency is proportional to the working frequency filter capacitor. In addition, when the output power is not up to the requirement, such as >250～300ma, the current can be expanded by an external power expansion tube, either bipolar or MOS expansion tube. The calculation formula and other parameters and their meanings are detailed See the detailed introduction at the bottom. The nominal meaning of peripheral components and their value calculation formula: Vout (output voltage) = 1.25V (1＋R1/R2) Ct (timing capacitor): Determines the internal operating frequency. Ct=0.000 004*Ton (working frequency) Ipk=2*Iomax*T/toff Rsc (current limiting resistor): Determines the output current. Rsc＝0.33/Ipk Lmin (inductance): Lmin=(Vimin－Vces)*Ton/ Ipk Co (filter capacitor): determine the output voltage ripple coefficient, Co = Io*ton/Vp-p (ripple coefficient) Fixed value parameters: Vces=1.0V　　ton/toff=(Vo+Vf－Vimin)/(Vimin－Vces)　　Vimin: the minimum value when the input voltage is unstable Vf=1.2V Fast switching diode forward voltage drop Other manual parameters:

Other manual parameters:

Parameter name	Symbol	Company	MC34063（Motorola USA）	ＣＷ34063（domestic）	IRM03A（Sharp Japan）
input voltage	Vin	V	2.5～40V	2.5～40V	2.5～40V
output voltage	Vout	V	1.25～40V	1.25～40V	1.25～40V
Maximum output current	Iomax	A	1.5A	1.5A	1.8AV
Maximum operating frequency	f	kHz	0.1～100KHZ	0.1～100KHZ	0.1～100KHZ
power	P	W	1.25W	1.25W	0.9WV
working temperature	Ta	degree	0～70 degree	0～70 degree	0～70 degree

ttention in practical application: 1: IN4148 can be used for fast switching diodes, and IN5819 must be used where high efficiency is required! 2: The voltage that the 34063 can withstand, that is, the sum of the absolute value of the input and output voltages cannot exceed 40V, otherwise it cannot work safely and stably.