908E624_12 Datasheet, PDF (30/39 Pages) Freescale Semiconductor, Inc – Integrated Triple High Side Switch Embedded MCU and Lin Serial Communication for 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 found on
the Freescale website: www.freescale.com.
VSUP Pins (VSUP1 and VSUP2)
Its recommended to place a high quality ceramic
decoupling capacitor close to the VSUP pins to improve
EMC/EMI behavior.
LIN Pin
For DPI (Direct Power Injection) and ESD (Electro Static
Discharge) it is recommended to place a high quality ceramic
decoupling capacitor near the LIN pin. 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 Pins (VDD and AGND)
Use a high quality ceramic decoupling capacitor to
stabilize the regulated voltage.
MCU Digital Supply Pins (EVDD and EVSS)
Fast signal transitions on MCU pins 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 pins.
MCU Analog Supply Pins (VREFH, VDDA, VREFL, and
VSSA)
To avoid noise on the analog supply pins 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
908E624
30
Analog Integrated Circuit Device Data
Freescale Semiconductor