DC-DC Circuit MC34063A Online Calculator
App description
1: Polarity is reversed.
2: Boost.
3：Depressor
Automatic calculation of peripheral component parameters for three typical circuits
How to use: Just enter the parameter you want in the left middle box, then click the “Calculate and refresh circuit diagram” button, it will automatically give all relevant peripheral component parameters and corresponding standard circuit drawings to make the design dc— The dc circuit is intelligent and efficient.
The nominal meaning of the peripheral components and the calculation formula for their values:
\(Vout(output voltage)=1.25V(1+R1/R2)\)
Ct: Determine the internal working 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): determines the output voltage ripple factor, Co = Io * ton / Vp - p (corrugation 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
Usage example
Input data: input voltage 35v; output voltage 220v; output current 240ma; output voltage ripple coefficient 65mv (pp); operating frequency 240khz
Perform calculations and refresh the circuit diagram:
Ct=141 pF
Ipk=3097 mA
Rsc=0.097 Ohm
Lmin=39 uH
Co=117 uF
R=180 Ohm
R1=1k R2=91k (115V)
Note
About the warning: If the parameter you entered exceeds the limit of 34063, it will automatically pop up a warning window to remind you to change them.
Special input: To design the polarity reversal circuit, add a negative sign in front of the input or output voltage number, such as -5v.
Input voltage range: 3-40V
Note in practical applications:
1: IN4148 can be used for fast switching diodes. IN5819 must be used when high efficiency is required!
2:34063 can withstand the voltage, that is, the sum of the absolute value of the input and output voltage can not exceed 40V, otherwise it can not work safely and stably.
Other manual parameters:
| parameter name | symbol | unit | MC34063(Motorola, USA) | ＣＷ34063(domestic) | IRM03A(Japan Sharp Corporation) |
|---|---|---|---|---|---|
| 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 | 1.8A |
| Maximum working frequency | f | kHz | 0.1～100KHZ | 0.1～100KHZ | 0.1～100KHZ |
| power | P | W | 1.25W | 1.25W | 0.9W |
| Operating temperature | Ta | Degree | 0～70度 | 0～70度 | 0～70度 |