Figure 97. Comparator Output Blanking - STMicroelectronics STM32WL5 Series Reference Manual

RM0453
21.3.7 Comparator output blanking function
The purpose of the blanking function is to prevent the current regulation to trip upon short
current spikes at the beginning of the PWM period (typically the recovery current in power
switches anti parallel diodes). It uses a blanking window defined with a timer output
compare signal. Refer to the register description for selectable blanking signals. The
blanking signal gates the internal comparator output such as to clean the comp_out from
spurious pulses due to current spikes, as depicted in the figure below.
Inverting input
(represents current limit)
Non-inverting input
(represents current)
(before blanking gate)
(blanking window)
(COMP output)
21.3.8 COMP power and speed modes
COMP1 and COMP2 power consumption versus propagation delay can be adjusted to have
the optimum trade-off for a given application.
PWRMODE[1:0] bits in COMPx_CSR registers can be programmed as follows:
00: High speed/full power
01: Medium speed/medium power
10: Medium speed/medium power
11: Very-low speed/ultra-low-power

Figure 97. Comparator output blanking

PWM
cmp_out
cmp_blk
comp_out
cmp_out
cmp_blk
Blanking gate
RM0453 Rev 5
Comparator (COMP)
current
spike
spurious
pulse
comp_out (to I/Os, TIM_BK ...)
MS30964V2
625/1450
631