dc-dc slides_2
description
Transcript of dc-dc slides_2
LARGE VALUE X2Y® IN DC-DC CONVERTERS
All commonly deployed DC-DC converter topologies: Buck, boost, flyback, SEPIC (Cuk topology is rare)
have at least one switched port. Parasitic capacitance across filter inductors passes
high frequency switching noise to filtered ports HF noise propagation through filtered and switched
ports is proportional to filter capacitor mounted ESL at each.
The unique construction of X2Y® capacitors results in essentially constant mounted ESL in larger body parts such as 1206, as in smaller body parts such as 0603.
Enables massive improvement in filter performance w/o extra magnetics
04/18/23 © X2Y Attenuators, LLC 1
LARGE BODY X2Y® IN DC-DC CONVERTERS
Example 1206 body part
uStrip configuration, mounted ESL < 40pH
> 25:1 HF noise attenuation versus well-mounted 1206 MLCC @ 1nH
04/18/23 © X2Y Attenuators, LLC 2
X2Y 1206 sizeon microstrip
|S21| Transfer Impedance, 1206 Size X2Y®
10uF RatedCapacitive Line
04/18/23 © X2Y Attenuators, LLC 4
DC-DC Converters
X2Y® Low ESL attenuates HF spikes at both input and output nodes for all common topologies: Buck Boost Flyback SEPIC
04/18/23 © X2Y Attenuators, LLC 5
DC-DC Converters
Filter parasitics pass HF noise often 200MHz or more to output
Solutions: Add series filters
Cost Space DC drop
Reduce filter capacitor inductance
Conventional 1206 caps > 1nH ESL
X2Y® 1206 caps, very low mounted ESL: 35-120pH
10X – 25X+ better than conventional 1206
Value depends on mounting configuration
04/18/23 © X2Y Attenuators, LLC 6
DC-DC Converters
X2Y® low ESL shunts HF noise:
Noise “Brick Wall” Reduced EMI from
converter into application PCB
Reduced EMI from application PCB conducted back through converter
No extra magnetics Reduces cost for
performance Saves space No extra DC drop