| ??? 03/12/07 00:28 Modified: 03/12/07 00:53 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#134731 - Do not overlook... Responding to: ???'s previous message |
...the minimum load current specification of LP8345! You must expect up to 100µA minimum load current with this chip. At lower load currents the regulator can go out of regulation!
The LTC1877 seems to need only up to 15µA (DC bias current). But, I think, a total supply current of 20...30µA is a bit more realistic, when taking the gate charge currents of internal switching MOSFET into account. Just do some tests and measure the actual supply current for a handful of these chips, best at varying ambient temperatures. Two additional hints: 1. Never take typicals in your calculation, but only worst case specs. 2. Try to avoid all sorts of electrolytics in ultra low supply current projects. They can show huge leakage currents!! Kai |
| Topic | Author | Date |
| Buck Regulator vs Linear and Efficiency Comparison | 01/01/70 00:00 | |
| Do not overlook... | 01/01/70 00:00 | |
| Good tips | 01/01/70 00:00 | |
| Use both? | 01/01/70 00:00 | |
| Nah | 01/01/70 00:00 | |
| Better linear? | 01/01/70 00:00 | |
They are nice, but do they allow 140mA? | 01/01/70 00:00 | |
| have a look at Power Trends (TI) | 01/01/70 00:00 | |
| Yes, but... | 01/01/70 00:00 |