1
1:0321
1:0351
Negative Voltage Hot Swap Controller
with Active Power Filter
Copyright IXYS CORPORATION 2000
www.ixys.com
98716 (08/21/00)
IXYS reserves the right to change limits, test conditions and dimensions.
Active Power Filter only Evalvation Board
CAUTION: These devices are
sensitvie to electrostatic discharge;
take caution when handling and
assembling this component.
Figure 1
Figure 1
Figure 1
Figure 1
Figure 1
4C
ACTIVE POWER FILTER
Although the IXHQ100 incorporates all the functions
necessary to implement a state of the art negative voltage hot
swap, a key feature of the IXHQ100 is its Power Active
Filter. For those size and cost sensitive applications
requiring only a Power Active Filter, the evaluation board
schematic is given in Figure 1,with bill of materials in Figure
4. Figure 2 is aripple rejection plot of the Power Active
Filter placed in the test circuit provided in Figure 3.
Some of the advantages of a Power Active Filter over
standard passive filters are:
* Significantly reduced size of the power supply bypass
capacitors.
* Eliminate magnetic noise generation by eliminating the
need for power filter inductors.
* Reduced sensitivity to power supply noise.
* Reduce size, weight, and overall system cost.
4
R
C>F
R
F>F
R
C>F!
R
F>F!
Backplane
Power
Source
V
!
Time
V
!
+
_
I
!
Time
I
!
C
@!
Load3
Card
Using the IXHQ100 active filter minimizes the number of extra de-coupling capacitors. This improves
noise immunity of the circuit board. Additionaly, low output impedance of the filter also improves the
performance of noise cancellation on power lines. An extra advantage of using the IXHQ100 over capaci-
tors is the amount of space one can save. Figure 6 gives an example of cross talk noise cancellation by the
IXHQ100 and an comparison of the size difference between an IXHQ100 chip and a capacitor (to scale).
IXHQ 100PI
IXHQ 100SI
Figure 5