Board layout
UM1615
4/8
DocID024329 Rev 1
3 Board
layout
3.1 Layout
recommendations
The ST8034xx family of devices includes an LDO block to generate V
CC
supply voltage for
the smartcard, which (in contrast to previous ST8024/8024L devices with a charge pump)
does not generate any noise and therefore even the requirements for a printed circuit board
layout and external component selection are not so strict (general PCB layout rules apply).
On the other hand, the LDO requires the input voltage (V
DDP
) to be at least about 100 mV
greater than the desired output voltage (V
CC
). Place the decoupling capacitors as close as
possible to the appropriate pin of the ST8034 device and use sufficiently wide PCB tracks.
Make the data and clock lines as short as possible and use a ground plane.
3.2 Component
placement
Figure 3. Component placement on the PCB
