908E624_10 Datasheet, PDF (33/40 Pages) Freescale Semiconductor, Inc – Integrated Triple High Side Switch with Embedded MCU and LIN Serial Communicationfor Relay Drivers

TYPICAL APPLICATIONS
EMC/EMI RECOMMENDATIONS
This paragraph gives some device specific
recommendations to improve EMC/EMI performance.
Further generic design recommendations can be e.g. found
on the Freescale website www.freescale.com.
VSUP Terminals (VSUP1 and VSUP2)
Its recommended to place a high-quality ceramic
decoupling capacitor close to the VSUP terminals to improve
EMC/EMI behavior.
LIN Terminal
For DPI (Direct Power Injection) and ESD (Electro Static
Discharge) it is recommended to place a high-quality ceramic
decoupling capacitor near the LIN terminal. An additional
varistor will further increase the immunity against ESD. A
ferrite in the LIN line will suppress some of the noise induced.
Voltage Regulator Output Terminals (VDD and AGND)
Use a high-quality ceramic decoupling capacitor to
stabilize the regulated voltage.
MCU Digital Supply Terminals (EVDD and EVSS)
Fast signal transitions on MCU terminals place high, short-
duration current demands on the power supply. To prevent
noise problems, take special care to provide power supply
bypassing at the MCU. It is recommended that a high-quality
ceramic decoupling capacitor be placed between these
terminals.
MCU Analog Supply Terminals (VREFH, VDDA and
VREFL, VSSA)
To avoid noise on the analog supply terminals it is
important to take special care on the layout. The MCU digital
and analog supplies should be tied to the same potential via
separate traces and connected to the voltage regulator
output.
Figure 20 and Figure 21 show the recommendations on
schematics and layout level and Table 15 indicates
recommended external components and layout
considerations.
VSUP
D1
+
C1
C2
L1
LIN
V1
C5
VSUP1
VSUP2
VDD
AGND
VREFH
VDDA
LIN
EVDD
C3
C4
VREFL
MM908E624
VSSA
GND
EVSS
Figure 20. EMC/EMI recommendations
Analog Integrated Circuit Device Data
Freescale Semiconductor
908E624
33