908E626 Datasheet, PDF (32/38 Pages) Freescale Semiconductor, Inc – Integrated Stepper Motor Driver with Embedded MCU and LIN Serial Communication

TYPICAL APPLICATIONS
FACTORY TRIMMING AND CALIBRATION
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:VSUP3)
Its recommended to place a high-quality ceramic
decoupling capacitor close to the VSUP terminals to improve
EMC/EMI behaviour.
LIN terminal
For DPI (Direct Power Injection) and ESD (Electro Static
Discharge) its recommended to place a high-quality ceramic
decoupling capacitor near the LIN terminal. An additional
varistor will further increase the immunity against ESD. A
ferrit 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 its important
to take special care on the layout. The MCU digital and
analog supplies should be tied to the same potential via
seperate traces and connected to the voltage regulator
output.
Figure 17 and Figure 18 show the recommendations on
schematics and layout level and Table 8 incidates
recommended external components and layout
considerations.
VSUP
D1
+
C1
C2
L1
LIN
V1
C5
VSUP1
VSUP2
VSUP3
LIN
VDD
VSS
VREFH
VDDA
EVDD
C3
C4
MM908E625
EVSS
VSSA
GND1
VREFL
GND2
Figure 17. EMC/EMI recommendations
908E626
32
Analog Integrated Circuit Device Data
Freescale Semiconductor