STM8L1/L2 motherboard

UM0629

8/26

Doc ID 15312 Rev 2

2

STM8L1/L2 motherboard

This motherboard is designed to work with an STM8L1 daughterboard.

2.1

Power supply

The motherboard is designed to be powered by a 5 V DC power supply and to be protected

from a wrong power plug-in event by PolyZen Inc. (auto rearmable fuse) U13. It is possible

to configure the evaluation board to provide 5 V power to the daughterboard through the

daughterboard connector.

●

The motherboard is powered by a 5 V DC power adapter connected to CN10, the

power jack on the board (PSU on silk screen for power supply unit).

●

5 V DC power is provided to the daughterboard through an extension connector and

can be set by jumper JP12 (DTB for daughterboard on silk-screen).

●

MCU_VDD can be selected by setting jumper JP11 and is connected to the

daughterboard directly through the daughterboard connector.

The power supply is configured by setting the jumpers JP11 and JP12 as described in

Table 1.

The LED LD6 is lit when the motherboard is powered correctly. JP3 is no longer used.

Table 1.

Power related jumpers

Jumper

Description

Setting

JP12

5 V power from power supply jack (CN10) is connected to the motherboard

when JP12 is set as shown to the right:

(default setting).

5 V power from power supply jack (CN10) is connected to the daughterboard

when JP12 is set as shown to the right:

In this case the motherboard and daughterboard are powered by a 5 V power

supply.

JP11

MCU_VDD is powered by a fixed 3.3 V power supply when JP11 is set as

shown to the right:

(default setting).

MCU_VDD is powered by a variable power supply from 1.8 V to 3.3 V,

adjusted by potentiometer RV4 (bottom left of the board), when JP11 is set as

shown to the right:

1

1