User Manual
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V 1.0
2021-08-25
XDPP1100 technical reference manual
Digital power controller
Current sense (IS)
3
Current sense (IS)
This chapter describes the current sense module and its submodules in detail. In addition, the user-
programmable settings for configuring different current sense features are described and relevant registers
provided.
Different applications require different current information. The XDPP1100 controller supports both primary
and secondary-side current sensing in order to obtain information on I
IN
and I
OUT
, respectively. It has two input
pin pairs for current sensing:
•
ISEN/IREF
•
BISEN/BIREF
Generally, either input pin pair can be used for both input and output current sensing. However, there are a few
application-related limitations. Below are the current sensing rules:
•
In a single-loop system for VMC, either input pin pair can be used for secondary-side or primary-side current
sense.
•
In a single-loop system for PCMC, the ISEN/IREF pin pair must be connected to the current being controlled;
I
OUT
for secondary-side PCMC and I
IN
for primary-side PCMC.
•
In a dual-loop system using either VMC or PCMC, the ISEN/IREF pin pair must be used for the first loop (Loop
0) and the BISEN/BIREF pin pair must be employed for the second loop (Loop 1).
A full-bridge full-bridge (FBFB) rectifier utilizing primary-side PCMC is an example of an application where both
currents I
IN
and I
OUT
are sensed. Typical connection of this converter is shown in
, where the current
sensing is emphasized in red. The primary-side current is sensed through a current transformer and fed to the
ISEN/IREF pin pair. The I
OUT
is sensed through a shunt and fed to BISEN/BIREF pin pair. In addition to the PCMC,
the primary-side current information is used for I
IN
telemetry and overcurrent fault protection. The secondary-
side current information is employed for various functionalities, e.g., I
OUT
telemetry and fault protections, droop
control and current sharing.
