User Manual
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V 1.0
2021-08-25
XDPP1100 technical reference manual
Digital power controller
Current sense (IS)
Figure 19
Simplified block diagram of the current sensing
The current sense information is provided to ISEN/IREF and BISEN/BIREF input pins as a voltage that is
proportional to the sensed current. There are different methods to obtain the current information, depending
on the application requirements. For the XDPP1100 controller, the supported current sensing methods are:
•
Shunt resistor
•
PCB trace
•
Current transformer (isolated topologies)
•
Integrated power stage (IPS) with integrated current sense
The main features and purposes of these methods are summarized in
Table 3
Current sensing methods
Sensing method
Advantages
Disadvantages
Applications
Shunt resistor
•
Most common solution
•
Simple
•
BOM cost
•
Additional power
dissipation
•
All applications
PCB trace
•
No additional bill of
materials (BOM) cost
•
No extra power
dissipation
•
Higher temperature
variation must be
compensated
•
Need for onboard
trimming for accuracy
•
Potential for higher
noise-to-signal ratio;
layout is critical
•
High-current
applications
Current transformer
•
Simple method
•
Additional BOM
•
Primary current
sensing in isolated
converters
Integrated current sense
of IPS
•
Board space saving
•
Integrated power
stage only supports
•
Non-isolated buck
converters
ISEN
IREF
Current sense
AFE
Current
estimator
(CE0)
Current sense ADC
Current sense
processor
(ISP0)
To telemetry, fault
processor, load-line
BISEN
BIREF
Current sense
AFE
Current
estimator
(CE1)
Current sense ADC
Current sense
processor
(ISP1)
To telemetry, fault
processor, load-line
