Datasheet
T Time-
Output1
Output2
PVDD1
PVDD2
Multiphase Operation
TPS55383 , , TPS55386
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......................................................................................................................................................................................... SLUS818 – SEPTEMBER 2008
Figure 28. Waveforms Resulting from Cascading PVDD1 from Output 2
In this configuration, the following conditions must be maintained:
1. Output 2 must be of a voltage high enough to maintain regulation of Output 1 under all load conditions.
2. The sum of the current drawn by Output 2 load plus the current into PVDD1 must be less than the overload
protection current level of Output 2.
3. The method of output sequencing must be such that the voltage on Output 2 is sufficient to support Output 1
before Output 1 is enabled. This requrement may be accomplished by:
a. a delay of the enable function
b. selecting sequential sequencing of Output 1 starting after Output 2 is in regulation
The TPS5538x may be configured to operate as a two-channel multiphase converter capable of delivering up to
6 A. Figure 29 indicates the recommended pin connections. In this configuration, FB2 must be tied to BP for the
maximum current configuration and the two output filter inductors must be the same value. Calculate R
COMP
and
C
COMP
as outlined for a single channel output, then use one-half the R
COMP
value and two times the C
COMP
value
as the compensation components. Contact the factory for further support.
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