Electronic Components Datasheet Search |
|
RH5RH363B-T2 Datasheet(PDF) 11 Page - RICOH electronics devices division |
|
RH5RH363B-T2 Datasheet(HTML) 11 Page - RICOH electronics devices division |
11 / 29 page 10 OPERATION OF STEP-UP DC/DC CONVERTER Step-up DC/DC Converter charges energy in the inductor when Lx Transistor (LxTr) is on, and discharges the energy with the addition of the energy from Input Power Source thereto, so that a higher output voltage than the input voltage is obtained. The operation will be explained with reference to the following diagrams : < Current through L > < Basic Circuits > RH5RH i2 L SD IOUT VOUT CL Lx Tr i1 VIN IL ILmin ILmax topen t ton toff T=1/fosc Step 1 : LxTr is turned ON and current IL (= i1 ) flows, so that energy is charged in L. At this moment, IL(=i1 ) is increased from ILmin (= 0) to reach ILmax in proportion to the on-time period (ton) of LxTr. Step 2 : When LxTr is turned OFF, Schottky diode (SD) is turned ON in order that L maintains IL at ILmax, so that current IL (= i2) is released. Step 3 : IL (=i2) is gradually decreased, and in the case of discontinuous mode, IL reaches ILmin (=0) after a time period of topen, so that SD is turned OFF. However, in the case of a continuous mode which will be mentioned later,the time period (toff) runs out before IL reaches ILmin (=0), so that LxTr is turned ON in the next cycle, and SD is turned OFF. In this case, ILmin does not reach zero, and IL (=i1) increases from ILmin (> 0). In the case of PWM control system, the output voltage is maintained constant by controlling the on-time peri- od (ton), with the oscillator frequency (fosc) being maintained constant. • Discontinuous Conduction Mode and Continuous Conduction Mode In the above two diagrams, the maximum value (ILmax) and the minimum value (ILmin) of the current which flows through the inductor are the same as those when LxTr is ON and also when LxTr is OFF. The difference between ILmax and ILmin, which is represented by ∆I, is : ∆I=ILmax–ILmin=VIN · ton/L=(VOUT–VIN) · topen/L .........................................Equation 1 wherein T=1/fosc=ton+toff duty (%)=ton/T · 100=ton · fosc · 100 topen ≤toff In Equation 1, VIN · ton/L and (VOUT–VIN) · topen/L are respectively show the change in the current at ON, and the change in the current at OFF. |
Similar Part No. - RH5RH363B-T2 |
|
Similar Description - RH5RH363B-T2 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |