| ??? 09/08/11 20:59 Read: times |
#183673 - LDO in HDO Application Responding to: ???'s previous message |
Andy Peters said:
Michael Karas said:
You didn't give much information as to why your LM1117 is getting heated up. I suspect that you have maybe 12V going in and you are taking 5V output at a pass current that is rather high. If using these numbers and a pass current of 333 mA then the power being wasted in the regulator is (12-5)*0.333 = 2.3 Watts. I don't understand why an LDO was chosen for a design with the input at 12V and an output of 5V. I never knew at the time of my posting what range of voltages the OP was working with. So I just pulled some numbers out from hat to then suggest why the regulator was getting too hot. It was not until after I posted that OP came back and responded that he was doing 5V to 3.3V conversion. Michael Karas |
| Topic | Author | Date |
| LM 1117 SOT 223 - Heatsinking | 01/01/70 00:00 | |
| Tight Suggestion | 01/01/70 00:00 | |
| I hate to change it, but | 01/01/70 00:00 | |
| Price Competition | 01/01/70 00:00 | |
| Price competition? | 01/01/70 00:00 | |
| Depends | 01/01/70 00:00 | |
| Switcher | 01/01/70 00:00 | |
| Switchers... | 01/01/70 00:00 | |
| LM1117 is an LDO | 01/01/70 00:00 | |
| 5V -> 3.3V | 01/01/70 00:00 | |
whoops | 01/01/70 00:00 | |
| LDO in HDO Application | 01/01/70 00:00 | |
| SOT223 will not work at all! | 01/01/70 00:00 | |
| "A Proper Heatsink" Indeed | 01/01/70 00:00 | |
| heat spreader | 01/01/70 00:00 | |
| LD1117 | 01/01/70 00:00 | |
| Alternative to LD1117 | 01/01/70 00:00 | |
| The LV33 can only deliver 500mA | 01/01/70 00:00 | |
| Current rating of LF33CV | 01/01/70 00:00 | |
| LD1086DT33 | 01/01/70 00:00 |