W254B Datasheet, PDF (15/16 Pages) SpectraLinear Inc – 133MHz Spread Spectrum FTG for Mobile Pentium® III Platforms

Layout Diagram
+3.3V Supply
VDDQ3
10:
C5 G G C6
FB
0.005 PF
C4
VDDQ3
10 PF
C3
GG
G
1^V
2^G
3
4
G
5
6
7
8^G
G
9^V
10 ^G
11
12 ^G
13 ^G
G
14 ^V
15 ^GG
16
17
18
19
20
21
22
23
24 ^G
W254B
+2.5V Supply
FB
VDDQ2
10 PF 0.005 PF
C1
C2
GG
G 48
47
V ₄₆
G
V ₄₅
G
G ₄₄
43
42
41
G ⁴⁰
39
V ₃₈
G
G ₃₇
36
35
34
33
G 32
V ₃₁
G
G G ₃₀
29
28
27
G ₂₆
25 ^{Core V}
G
FB = Dale ILB1206 - 300 (300:@ 100 MHz)
Ceramic Caps C1, C3 & C5 = 10–22 PF C2 & C4 = 0.005 PF ^{C6 = 0.1 PF}
G = VIA to GND plane layer V =VIA to respective supply plane layer
Note: Each supply plane or strip should have a ferrite bead and capacitors
Rev 1.0, November 20, 2006
Page 15 of 16