Datasheet

SYSTEM SEQUENCING AND TPS65820 OPERATING MODES
LOADPOWERUP DEFAULTSIN
I2CREGISTERS
CONNECT AC , USBORBAT PIN TO
OUT PIN
DISABLEPOWERGOODFAULT
DETECTION
INT PIN = HIGHIMPEDANCE
POR_FLAG= HI
OFF
ANY
STATE
V(AC) > V
UVLO
OR
V(USB) > V
UVLO
OR
V(BAT) > V
UVLO
V(OUT) < V
UVLO
PGOODFAULT : A NON- MASKEDBIT OF THE
POWER _GOODI2CREGISTER TOGGLES
FROMLO TOHI
STANDBY ON : SM1 ANDSM2 SET INSTANDBY
MODEBY GPIOORI 2CCOMMAND
STANDBY OFF : SM1 ANDSM2 EXIT STANDBY
MODEBY GPIOOR
I2CCOMMAND
RESETTIMER : VALUESET BY CAPACITOR
CONNECTED TO TRSTPWONPIN
I2CSOFT_RESETBIT LOCATEDIN
SOFT_RESET REGISTER, BIT B0
POWERUP
SYS_IN INITIAL DEGLITCH
TIMER T
INSYS
EXPIRED
V < V
THERMAL FAULT
I2C SOFT_RESET REGISTER
BIT SLEEP_MODE = HI
(SELF - CLEARED)
AND
OR
OR
(SYS_IN) (LOW_SYS)
FOR 5 msec
PGOOD
FAULT
POWER
CYCLE
AND
SLEEP NOT SET BY
THERMAL FAULT
PROCESSOR
STANDBY STATE
RESPWRON = HI
PGFORSM1&SM2
ismasked
ENABLESTATE
RESPWRON=LO,
RESET I2CENGINE
- UP TIMER
SEQUENCESTATE
START INTEGRATED
SUPPLY START - UP SEQUENCE
RESPWRON
= LO
POWERGOOD
CHECKSTATE
RESPWRON=HI
ENABLEPOWERGOODCOMPARATORS
INT PINMODESET BY INTERRUPT
CONTROLLER
=HI
RESETSTATE
RESPWRON=LO
START SYSTEMRESET PULSE TIMER
WHENHOT_RESET=HI
RESET
TIMEREXPIRES
V(SYS_IN) > AND
V(OUT) > V
NOPGOOD
FAULT
STANDBY
ON
STANDBY
OFF
PGOOD
FAULT
RESPWRON=LO
V(HOT_RESET)=LO
OR
I2CSOFT_RESET
REGISTERBIT
SOFT_RST = HI
V(HOT_RESET)=HI OR
I2CSOFT_RESET
REGISTERBIT
SOFT_RESET = LO
(SELFCLEARED)
V(HOT_RESET)=LO
OR
I2CSOFT_RESET
REGISTERBIT
SOFT_RST= HI
UVLO
V
(LOW_SYS)
POWERUP DEFAULTSLOADED
IN ALL I2CREGISTERS
(ExceptINT_ACKn)
POWERDOWNRAILS,
WAIT 5msec
START BOOT
SLEEP STATE
ONLY RTC_LDOISON
POWERPATH ACTIVE
RESPWRON = 0
REGISTERCONTENTSNOT RESET
INTERRUPT CLEARED
RESET I2CENGINE
ENABLEI2CENGINE
RESET I2CENGINE
RESET I2CENGINE
RESET I2CENGINE
NORMAL MODE
RESPWRON
HOTPLUGDEGLITCH
START SYS_IN
INITIAL DEGLITCH TIMER
T
INSYS
TPS65820
www.ti.com .............................................................................................................................................................. SLVS663B – MAY 2006 – REVISED APRIL 2008
The TPS65820 has a state machine that controls the device power up and power down sequencing. The main
operating modes are shown in the state diagram below:
Figure 28. TPS65820 State Diagram
POWER-UP – If the AC, USB and BAT pin voltages are below the internal UVLO threshold V
UVLO
(2.5 V typ) all
IC blocks are disabled and the TPS65820 is not operational, with all functions OFF. When an external power
source or battery with voltage greater than the V
UVLO
voltage threshold is applied to AC/USB or BAT pins the
internal TPS65820 references are powered up, biasing internal circuits. When all the main internal supply rails
are active the TPS65820 I
2
C registers are set to the power-up default values, shown in Table 3 :
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