Comparator; Table 12. Configuration Elements Related To Opamp1; Table 13. Configuration Elements Related To Comp2 - ST STM32L4R9I-EVAL User Manual

Hardware layout and configuration
The R108 resistor in series with PA0 is beneficial for reducing the output offset.
Table 12
OpAmp1 function.
Element
SB39
SB38
R214
R216
SB40
R215
R221
6.18.2

Comparator

STM32L4R9AII6 provides two onboard comparators, one of which, Comp2, is made
accessible on STM32L4R9I-EVAL. Comp2 has its non-inverting input and its output routed
to I/O ports PB4 and PB5, respectively. The input is accessible on the terminal 3 of the JP5
jumper header. On top of the possibility of routing either the potentiometer or LDR to PB4,
an external source is connectible to it, using the terminal 3 of JP5.
The PB5 output of the comparator is accessible on test point TP6. Refer to the schematic
diagram.
Table 13
Comp2 function.
Element
R200
SB22
36/72
shows the configuration elements and their settings allowing them to access the

Table 12. Configuration elements related to OpAmp1

Setting
SB38 open
SB39 closed
R214 out
SB38 open
SB39 closed
R214 in
SB38 closed
SB39 open
R214 out
R216 in
SB40 open
R216 out
SB40 closed
R215 in
R221 out
R215 out
R221 in
shows the configuration elements and their settings allowing them to access the

Table 13. Configuration elements related to Comp2

Setting
R200 out
SB22 closed
R200 in
SB22 open
OpAmp1_INP is routed to pin PA0 of STM32L4R9AII6.
Default setting.
PA0 port of STM32L4R9AII6 is routed to MFX_IRQ_OUT or
motor control signal.
PA0 port of STM32L4R9AII6 is routed to the motor-control signal.
Default setting.
OpAmp1_INM is routed to pin PA1 of STM32L4R9AII6.
PA1 port of STM32L4R9AII6 is routed to the motor-control signal.
OpAmp1_VOUT is routed to pin PA3 of STM32L4R9AII6.
Default setting.
OpAmp1_VOUT is not routed to pin PA3 of STM32L4R9AII6. PA3
port of STM32L4R9AII6 is routed to OctoSPI1_CLK.
Default setting.
Comp2_INP is routed to pin PB4 of STM32L4R9AII6.
PB4 port of STM32L4R9AII6 is routed to the TRST signal.
UM2248 Rev 4
Configuration
Configuration
UM2248