SAA7144 NXP Semiconductors, SAA7144 Datasheet - Page 56

• Manufacturer Part Number: SAA7144
• Manufacturer: NXP Semiconductors

Specifications of SAA7144

• Package Type: LQFP
• Lead Free Status / RoHS Status: Compliant

Philips Semiconductors
9397 750 14454
Product data sheet
15.1 Recommended printed-circuit board layout
The SAA7144HL consists of analog and digital areas. Due to this special care needs to be
taken for design of layout regarding crosstalk by analog and digital supply interaction.
It is recommended to use four layer Printed-Circuit Board (PCB). Top and bottom layer for
signal wires, one for ground plane and one for supply plane. Split of analog and digital
supply layer areas shows best video performance.
The ground and supply plane need to be close to each other to achieve capacitive
behavior. Due to this size, distance and also material is responsible for layer capacitor
value. Additional decoupling isles are required.
Fig 29. Supply method.
analog supply:
VDD
VSS
ANALOG SUPPLY LAYERS 2a, 3a
100 nF
A
A
A11
A12
A21
A22
A31
A32
A41
A42
layer 3a
direct to plane
layer 2a
Rev. 01 — 21 April 2005
C
L (HF trap)
C
C
C
C
layer
SAA7144HL
3.3 V
GND
DIGITAL SUPPLY LAYERS 2b, 3b
A
VDD
digital supply:
VSS
D
D
Quadruple video input processor
4
R
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
direct to plane
layer 3b
layer 2b
SAA7144HL
C
L (HF trap)
layer
layer:
2a
2b
3a
3b
1
4
signals
VSS
VSS
VDD
VDD
signals
001aab320
3.3 V
GND
A
D
A
D
D
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