Application description

AN2979

4/12

Doc ID 15651 Rev 1

Figure 1.

Capacitor charging curve

The figure below shows the connection of the comparator to the required external

components.

Figure 2.

Comparator connections

1.

Note:

When using the STM8L101-EVAL evaluation board you need to connect the PB0 pin to the

PC4 pin. This way you use the resistor and capacitor already present on the board (no

hardware needed). Pin PC4 is configured as input floating to avoid any conflict.

PWM output

Capacitor charging curve

T(ms)

3.3

2.5

2

1.5

1

0.5

1

2345

678

9

(V)

3

-

+

C=100 nF

PB0/PC4

PA6

PD2

COMP_OUT

R=10 k