| ??? 11/30/05 13:15 Read: times |
#104410 - Additional pi-filters are often needed! Responding to: ???'s previous message |
K.ganeshan said:
I'll tryout these devices. Take care, the types with unregulated outputs often show enormous high frequency ripple, which should be filtered out! This types highly profit from a pi-filter at each output consisting of two 47µF/35V aluminium electrolytics and a 6-hole-choke, forming a "pi". Choose a 6-hole-choke that shows an effective inductivity of about 10µH at lower frequencies. This pi-filter shows a small ripple at resonance, which is damped by the equivalent series resistance of used aluminium electrolytics. Advantage, no additional voltage drop across pi-filter must be accepted. If any ripple is unwanted, then put a 0R68 resistor in series to 6-hole-choke. Such a pi-filter should also be present at input of DC/DC converter. Even DC/DC converters providing regulated output voltages highly profit from such a pi-filter at input. Kai |
| Topic | Author | Date |
| DC to DC converter | 01/01/70 00:00 | |
| Power Trends | 01/01/70 00:00 | |
| Switching regulators | 01/01/70 00:00 | |
| Traco | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| Additional pi-filters are often needed! | 01/01/70 00:00 | |
| the frequency is high | 01/01/70 00:00 | |
| main point: low pass filter | 01/01/70 00:00 | |
| the crux | 01/01/70 00:00 | |
| Of course! | 01/01/70 00:00 | |
| switching frequency? | 01/01/70 00:00 | |
About 100kHz | 01/01/70 00:00 | |
| Volume Vs Cost debate | 01/01/70 00:00 | |
| decisions, decisions | 01/01/70 00:00 | |
| If you are ready to redesign... | 01/01/70 00:00 | |
| Kai, when recommending things like this, | 01/01/70 00:00 | |
| Datasheet... | 01/01/70 00:00 |