AAT4685 Datasheet, PDF (12/17 Pages) Skyworks Solutions Inc. – thermal shutdown protection

System Flowchart
Power ON
All functions OFF
UVLO : ON
V(IN) > UVLO ^N
Y
OVP : ON
Standby
DATA SHEET
AAT4685
Over-Voltage Protection Switch with OCP and BOVP
EN = L
N
Y
Reset :
Timers reset
Counters reset
FLT = HiZ
BOVP, TSD : ON
FLT= H iZ
N
Y
Wait tDGL
(8ms)
OCP : ON
Any State:
If V(IN) < UVLO go to “Power ON”
If EN = H go to “Standby”
Turn On OVP
switch,
FLT = HiZ
VIN > OVP
Y
N
FLT state
Turn Off OVP
swtch,
FLT = L
V(IN) < OVP ^Y
N
Wait tOVP_REC
(8ms)
VBAT > BOVP ^Y
N
FLT state
Blanking Time ^Y
180μs
N
Turn Off OVP
switch,
FLT = L,
Incr BOVP counter
count <15 ? ^Y
N
VBAT < BOVP ^Y
N
I > I_OCP
Y
N
Limit
Current
EN = H
Y
N
Goto
Standby
FLT state
Blanking Time ^Y
180μs
N
Turn Off OVP
switch,
FLT = L,
Incr OCP counter
Y
count <15 ?
N
Wait tOCP_REC
(64ms)
TJ > TSHDN
Y
N
FLT state
Turn Off OVP
swtch,
FLT = HiZ
TJ < TSHDN -15 ^Y
N
EN = H
Y
N
Goto
Standby
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
12
201960A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • May 16, 2012