PAC5220 Datasheet, PDF (23/73 Pages) Active-Semi, Inc – Power Application Controller

PAC5220
Power Application Controller
Figure 10-5. Linear Regulators
PAC5220
VP
V (12V typical)
P
REGO
VSYS
VCCIO
VCC33
VCC18
VSS
VSSA
V & V (5V)
SYS
CCIO
(1)
4.7µF
1µF 1µF
(1) _{5V I/O connection shown.}
Connect instead to a 4.7µF
capacitor for 3.3V I/O.
10.3.3. Power Up Sequence
The MMPM follows a typical power up sequence as in the Figure 10-6 below. A typical sequence begins with
input power supply being applied, followed by the safe start up and start up durations to bring the switching
supply output VP to 9V, before the linear regulators are enabled. When all the supplies are ready, the internal
clocks become available, and the microcontroller starts executing from the program memory. During
initialization, the microcontroller can reconfigure the switching supply to a different VP regulation voltage such as
12V and to an appropriate switching frequency and switching mode. The total loading on the switching supply
must be kept below 25% of the maximum output current until after the reconfiguration of the switching supply is
complete. For AC input supply applications, the start up sequence includes an additional charging time for V HM
depending on the start-up resistor and capacitor values.
Figure 10-6. Power Up Sequence
V or V
IN
HM
V
P
V and V
SYS
CCIO
V
CC33
V
CC18
14.8V
Internal clocks
Power on reset
Safe start up
Start up
6ms
Regulators Power-on-
enabled reset delay
1ms
Reconfiguration by firmware
4.3V
4V
V (9V start up default)
P
76%
Microcontroller
reset
Microcontroller
initializing
System operation
V or V
IN
HM
V (12V)
P
V and V (5V)
SYS
CCIO
V (3.3V)
CC33
V (1.8V)
CC18
Microcontroller
executing
10.3.4. Hibernate Mode
The IC can go into an ultra-low power hibernate mode via the microcontroller firmware or via the optional push
button (PBTN, see Push Button description in Configurable Analog Front End). In hibernate mode, only a
minimal amount (typically 18µA) of current is used by VHM, and the MMSS controller and all internal regulators
- 23 -
Rev 1.0‒February 25, 2014