5.2

Power supply filtering

As mentioned in Section 2 Pin and signal description, the power supply of the circuit must be filtered using the

circuit shown in the figure below.

Figure 12. Mandatory filtering capacitors on VPS

TPM

Host device

SPI_MOSI

SPI_RST

VPS

GND

100 nF

10 µF

+

-

SPI_MISO

SPI_CLK

SPI_CS

SPI_PIRQ

1.

10 µF and 100 nF are recommended values. The minimum required capacitor value is 2.1 µF (2 µF in

parallel with 100 nF).

Table 11. Maximum VPS rising slope

Symbol

Parameter

Value

Unit

SVPS

Maximum VPS rising slope

3.3

V/µs

ST33TPHF2XSPI

Power supply filtering

DS14186 - Rev 1

page 18/35