| ??? 07/16/05 10:06 Read: times |
#97481 - LP2980, multiplexing Responding to: ???'s previous message |
LP2980 is rather critical refering to output capacitor! Do only use 2µ2/10V tantal. Neither aluminium electrolytics nor ceramics!
Disconnect everything connected to micro, if possible. Then connect it piece for piece until the micro runs ill again. Multiplexing always needs enhanced power supply decoupling measures!! Try to use RC-filters instead of a simple capacitor solution. Even very small resistance values can considerably help! Also additional ferrite beads can help to kill the higher harmonics. For decoupling of multiplexing section ceramic high caps like 1...10µF/X5R are perfectly suited. Also a splitting of ground plane can help: Divide the ground plane into one section for the multiplexing stuff and one for the rest circuitry. This is especially suited if really heavy multiplexing currents are flowing. Kai |
| Topic | Author | Date |
| LPC932 at powerup | 01/01/70 00:00 | |
| what clock? | 01/01/70 00:00 | |
| clock | 01/01/70 00:00 | |
| Scope time | 01/01/70 00:00 | |
| LP2980, multiplexing | 01/01/70 00:00 | |
| To Ijaz and Kai | 01/01/70 00:00 | |
| Ah yes... | 01/01/70 00:00 | |
| Maybe reset chip is unsuited? | 01/01/70 00:00 | |
Problem solved | 01/01/70 00:00 |