1-4
Power Signals
1.2 Power Signals
Table 1-1. Power and Ground Signal Inputs
Power Name
Description
V
DD
Internal Logic Power
V
DD
dedicated for use with the device core. The voltage should be well-regulated and the
input should be provided with an extremely low impedance path to the V
DD
power rail.
V
DDH
Input/Output Power
This source supplies power for the I/O buffers. The user must provide adequate external
decoupling capacitors.
V
CCSYN
System PLL Power
V
CC
dedicated for use with the system Phase Lock Loop (PLL). The voltage should be
well-regulated and the input should be provided with an extremely low impedance path to the
V
CC
power rail.
V
CCSYN1
SC140 PLL Power
V
CC
dedicated for use with the SC140 core PLL. The voltage should be well-regulated and
the input should be provided with an extremely low impedance path to the V
CC
power rail.
GND
System Ground
An isolated ground for the internal processing logic. This connection must be tied externally
to all chip ground connections, except GND
SYN
and GND
SYN1
. The user must provide
adequate external decoupling capacitors.
GND
SYN
System PLL Ground
Ground dedicated for system PLL use. The connection should be provided with an extremely
low-impedance path to ground.
GND
SYN1
SC140 PLL Ground 1
Ground dedicated for SC140 core PLL use. The connection should be provided with an
extremely low-impedance path to ground.