atsam3303b ATMEL Corporation, atsam3303b Datasheet - Page 22

• Manufacturer Part Number: atsam3303b
• Description: Atsam3303b Audio Processing
• Manufacturer: ATMEL Corporation

12. Recommended Board Layout
22
ATSAM3303B
Like all HCMOS high integration ICs, the following simple rules of board layout are mandatory
for reliable operation:
All GND, VC33, VC18 pins should be connected. A GND plane is strongly recommended. The
board GND + VC33 distribution should be in grid form.
Recommended VC18 decoupling is 0.1 µF at each corner of the IC with an additional 10 µF
decoupling close to the crystal. VC33 requires a single 0.1µF decoupling.
The paths between the crystal, the crystal compensation capacitors, the LFT filter R-C-R and the
ATSAM3303B should be short and shielded. The ground return from the compensation capaci-
tors and LFT filter should be the GND plane from ATSAM3303B.
Parallel layout between D0 - D7 and WA0 - WA21/WD0 - WD15 should be avoided. The D0 - D7
bus is an asynchronous type bus. Even on short distances, it can induce pulses on WA0 -
WA21/WD0 - WD15 that can corrupt address and/or data on these buses.
A ground plane should be implemented below the D0 - D7 bus, which is connected to the host
and to the ATSAM3303B GND.
A ground plane should be implemented below the WA0 - WA21/WD0 - WD15 bus, which is con-
nected to the ROM/Flash grounds and to the ATSAM3303B.
A specific AGND ground plane should be provided, which is connected to the GND ground by a
single trace. No digital signals should cross the AGND plane.
Refer to the Codec vendor recommended layout for correct implementation of the analog
section.
• GND, VC33, VC18 Distribution and Decouplings
• Crystal, LFT
• Buses
• Analog Section
6091D–DRMSD–12-Feb-07