![](http://datasheet.mmic.net.cn/390000/SYM53C1010-33_datasheet_16836324/SYM53C1010-33_119.png)
Power and Ground Signals
3-25
3.7 Power and Ground Signals
Table 3.21
describes the Power and Ground Signals group.
Table 3.21
Power and Ground Signals
Name
1
Bump
Type Strength Description
V
SS_IO
C3, C21, D4, D12,
D20, K10–14, L10–14,
M4, M10–14, M20,
N10–14, P10–14, Y4,
Y12, Y20, AA3, AA21.
D7, D10, D14, D17,
G4, G20, K4, K20, P4,
P20, U4, U20, Y7,
Y10, Y14, Y17.
B22, B23, D3, E4,
Y13, AB3, AB18,
AB23, AC1.
A22, D2, D21, F3,
Y15, AB2, AA22,
AB19, AC2, AC21.
B2, C20
G
N/A
Ground for PCI bus drivers/receivers, SCSI
bus drivers, local memory interface drivers,
and other I/O pins.
V
DD_IO
P
N/A
Power for PCI bus drivers/receivers, SCSI
bus drivers/receivers, local memory interface
drivers/receivers, and other I/O pins.
V
DD
_CORE
P
N/A
Power for core logic.
V
SS
_CORE
G
N/A
Ground for core logic.
V
DD
_A
2
P
N/A
Power for analog cells (clock quadrupler and
DIFFSENS logic).
Ground for analog cells (clock quadrupler
and DIFFSENS logic).
Power for SCSI Function A RBIAS circuit.
Power for SCSI Function B RBIAS circuit.
Used to connect an external resistor to
generate the LVD Link pad bias current. The
resistor value should be 10 k
. Connect the
other end of the resistor to V
DD
.
These pins are reserved or have no internal
connection.
V
SS
_A
2
B20, C2
G
N/A
V
DD
_Bias
V
DD
_Bias2
RBIAS
M22
A11
M21
P
P
I
N/A
N/A
N/A
NC
A1, A13, A23, B1, B3,
B13, B16, B21, D16,
P22, P23, U22, U23,
AB22.
N/A
N/A
1. The I/O driver pad rows and digital core have isolated power supplies as indicated by the “I/O” and
“CORE” extensions on their respective V
SS
and V
DD
names. Connect the power and ground pins
directly to the primary power and ground planes of the circuit board. Apply bypass capacitors of
0.01
μ
F between adjacent V
SS
and V
DD
pairs wherever possible. Do not connect bypass capacitors
between V
SS
and V
DD
pairs that cross power and ground bus boundaries.
2. To reduce signal noise that can affect FSN functionality, place a ferrite bead in series with the V
DD
-A
and V
SS
-A pins. The recommended rating of the bead is 150 Ohms at 100 MHz.