MC34063A芯片典型升降压电路外围元件计算器

The maximum ambient tempera

yellow table. The value of maxi

temperature Tj = 150°C.

(DO NOT CHANGE)

2) Input Conduction Loss Parameters from Free-wheeling Diode Datasheets

- Found in Electrical Characteristics of Datasheet,

Darlington Configuration

3) Set D IL/IL(avg)

For Maximum Output Current it is suggested that ΔIL should be chosen to be less than 10% of the average inductor curre This will help prevent Ipk (sw) from reaching the current limit threshold set by RSC. If the design goal is

inductance value, let ΔIL = 2*IL(avg). This will proportionally reduce output current capability.

D IL / IL(avg)

D IL

4) Input target frequency

5) The spreadsheet calculates key parameters for the remaining component selec

?i L

* increasing inductance decreas 6) Efficiency / Power Loss

ximum ambient temperature is related to one-layer PCB with parameters mentioned in the above

yellow table. The value of maximum ambient temperature is calculated for maximum allowable junction temperature Tj = 150°C.

Input Voltage: 4V < Vin < 40V

Output Voltage: 1.25V < Vout < (Vin*Dmax)

4%

of Datasheet,

0% of the average inductor current, IL(avg).

oal is to use a minimum

ponent selection

erter this equals Iout

this equals Iout + Iripple/2

* increasing inductance decreases ripple current ata sheet or measurement).

data sheet. Leave blank if not available.

Rev 0.1 7/22/09