Electronic Components Datasheet Search |
|
LT1614IS8 Datasheet(PDF) 7 Page - Linear Technology |
|
LT1614IS8 Datasheet(HTML) 7 Page - Linear Technology |
7 / 16 page 7 LT1614 OPERATIO When Q1 turns off during the second phase of switching, the SWX node voltage abruptly increases to (VIN + |VOUT|). The SW node voltage increases to VD (about 350mV). Now current in the first loop, begining at C1, flows through L1, C2, D1 and back to C1. Current in the second loop flows from C3 through L2, D1 and back to C3. Load current continues to be supplied by L2 and C3. An important layout issue arises due to the chopped nature of the currents flowing in Q1 and D1. If they are both tied directly to the ground plane before being combined, switching noise will be introduced into the ground plane. It is almost impossible to get rid of this noise, once present in the ground plane. The solution is to tie D1’s cathode to the ground pin of the LT1614 before the combined cur- rents are dumped into the ground plane as drawn in Figures 4, 5 and 6. This single layout technique can virtually eliminate high frequency “spike” noise so often present on switching regulator outputs. Output ripple voltage appears as a triangular waveform riding on VOUT. Ripple magnitude equals the ripple current of L2 multiplied by the equivalent series resistance (ESR) of output capacitor C3. Increasing the inductance of L1 and L2 lowers the ripple current, which leads to lower output voltage ripple. Decreasing the ESR of C3, by using ceramic or other low ESR type capacitors, lowers output ripple voltage. Output ripple voltage can be reduced to arbitrarily low levels by using large value inductors and low ESR, high value capacitors. Figure 5. Switch-On Phase of Inverting Converter. L1 and L2 Current Have Positive dI/dt Figure 6. Switch-Off Phase of Inverting Converter. L1 and L2 Current Have Negative dI/dt + L1 L2 C2 –(VIN + VOUT) SW SWX D1 Q1 1614 F05 C1 C3 RLOAD –VOUT VIN VCESAT + L1 L2 C2 VIN + VOUT+ VD SW SWX D1 Q1 1614 F06 C1 C3 RLOAD –VOUT VIN VD |
Similar Part No. - LT1614IS8 |
|
Similar Description - LT1614IS8 |
|
|
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 |