mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 259

• Manufacturer Part Number: mfr4300
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

Appendix C
Printed Circuit Board Layout Recommendations
The PCB must be laid out carefully to ensure proper operation of the voltage regulator and the CC. The
following rules must be observed:
Figure C-1
Table C-1
Freescale Semiconductor
•
•
•
•
•
•
•
Every supply pair must be decoupled by a ceramic capacitor connected as near as possible to the
corresponding pins (Cd).
The central point of the ground star should be the VSSR pin.
Low-ohmic low-inductance connections should be used between VSSX and VSSR.
VSSOSC must be directly connected to VSSR.
Traces of VSSOSC, EXTAL and XTAL must be kept as short as possible. Occupied board area for
C1, C2, C3 and Q should be as small as possible.
Other signals or supply lines should not be routed under the area occupied by C1, C2, C3, and Q
and the connection area of the CC.
The central power input should be fed in at the VDDA/VSSA pins.
provides suggested values for the external components.
Component
shows a recommended PCB layout (64-pin LQFP) for standard Pierce oscillator mode, while
Cload
C1
C2
C3
C4
Cd
R
R
Q
B
S
Table C-1. Suggested External Component Values
VDDR, VDDX filter cap
VDDOSC filter cap
VDD2_5 filter cap
OSC resistance
OSC resistance
VDDA filter cap
OSC load cap
OSC load cap
Purpose
Quartz
MFR4300 Data Sheet, Rev. 3
ceramic X7R/tantalum
NDK NX8045GA
ceramic X7R
ceramic X7R
ceramic X7R
ceramic X7R
ceramic X7R
Type
Printed Circuit Board Layout Recommendations
0 : (i.e. short-circuit)
100– 220nF
100– 220nF
100– 220nF
100– 220nF
40 MHz
Value
1 M:
2pF
2pF
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