Rev. 1.0, 02/00, page 1131 of 1141
Appendix E Usage Notes
E.1
Power Supply Rise and Fall Order
Figure E.1 shows the order in which the power supply pins rise when the chip is powered on, and
the order in which they fall when the chip is powered down. If the power supply voltages cannot
rise and fall simultaneously, power supply operations should be carried out in this order.
•
At power-on, wait until the microcomputer section power supply (V
CC
) has risen to the
prescribed voltage, then raise the other analog power supplies.
•
At power-down, drop the analog power supplies first, followed by the microcomputer section
power supply (V
CC
).
When powering up and down, the voltage applied to the pins should not exceed the respective
power supply voltage.
V
CC
, AV
CC
V
CC
AV
CC
SV
CC
OSD
Vin
: Microcomputer section power supply voltage
: A/D converter power supply voltage
: Servo section power supply voltage
: Section power supply voltage
: Pin applied voltage
SV
CC
, OV
CC
V
CC
, AV
CC
SV
CC
Vin
Vin
Figure E.1 Power Supply Rise and Fall Order
In power-down modes (except sleep mode), the analog power supplies can be controlled at the V
SS
level to reduce current dissipation. When the microcomputer section power supply (V
CC
) is
dropped to the backup voltage in a power-down mode, the order shown in figure E.2 should be
followed. Make sure that the voltage applied to the pins does not exceed the respective power
supply voltage.
The A/D converter power supply (AV
CC
) should be set to the same potential as the microcomputer
section power supply (V
CC
). In all power-down modes except sleep mode, AV
CC
is turned off
inside the device. At this time, the AV
CC
current dissipation is defined as AISTOP.