NCP3902
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8
Table 5. ACRONYMS AND DEFINITIONS
Label Description
Loss of Power Both USBIN and OUT below the UVLO threshold
Application of Power USBIN and/or OUT above the UVLO threshold
Enable EN_N pin is low, debounced for Tilen
Disable EN_N pin is high, debounced for Tihen
Valid VBUS USBIN above the UVLO threshold debounced for Tdebusb, the voltage at OUT is a don’t care
Invalid VBUS Inverted signal of ‘Valid VBUS’
Valid VOUT OUT above the UVLO threshold debounced for Tdebout and no ’Valid VBUS’
Invalid VOUT Inverted signal of ‘Valid VOUT’
VOUT Discharged OUT below the UVLO threshold, no debounce
OTG Enable FLAG_N pin is forced low by the system while FLAG_N was pulled high by the device, debounced for Tilfl
OTG Disable FLAG_N pin is released by the system and FLAG_N is pulled up by the device, debounced for Tihfl
Out of Temp Die temperature exceeds thermal shutdown threshold
In Temp Die temperature falls below thermal shutdown threshold
Tinit Power up and initialization duration
Tdis Discharge duration
OFF Device is not powered
INIT EN_N don’t care, Switch open, RX_N and FLAG_N low.
Startup of the device including analog and digital blocks and reading of OTP fuses. Duration Tinit.
TSD SLAVE EN_N don’t care, Switch open, RX_N high, FLAG_N low
Entered from any slave state at Out of Temp condition
TSD AUTO EN_N low, Switch open, RX_N high, FLAG_N low
Entered from any autonomous state at Out of Temp condition
AUTO READY EN_N low, Switch open, RX_N and FLAG_N low.
Autonomous mode is detected during INIT state. Can also be entered from AUTO DISCH (if invalid VBUS).
AUTO DISCH EN_N low, Switch open, RX_N high, FLAG_N low.
A ‘Valid VBUS’ is detected, discharge load activated on OUT and USBIN, minimum duration Tdis. The
‘VOUT Discharged’ condition must be met before exiting for AUTO ON (verification done for safety reasons)
AUTO ON EN_N low, Switch closed, RX_N high, FLAG_N low.
Under normal conditions this state is only exited upon loss of power (eg. USB removal).
OTG READY EN_N low, Switch open, RX_N low, FLAG_N high.
A ‘Valid VOUT’ is detected.
OTG ON EN_N low, Switch closed, RX_N high, FLAG_N forced low by the system.
An ‘OTG enable’ condition is detected
OTG DISCH EN_N low, Switch open, RX_N high, FLAG_N high (no longer forced low by the system).
Discharge load activated on OUT and USBIN, duration Tdis, exited for OTG READY
SLAVE READY EN_N high, Switch open, RX_N and FLAG_N low.
Slave mode is detected during INIT state. Can also be entered from certain autonomous states if EN_N was
initially low upon exiting the INIT state.
OTG SLAVE READY EN_N high, Switch open, RX_N low, FLAG_N high.
A ‘Valid VOUT’ is detected.
SLAVE ON EN_N low, Switch closed, RX_N high, FLAG_N low.
Exit While in one of the autonomous states, EN_N is made high leading to an Exit to a slave state. The mapping
of the states is as follows:
AUTO READY, AUTO DISCH ³ SLAVE READY
AUTO ON, OTG ON, OTG DISCH ³ SLAVE READY
OTG READY ³ OTG SLAVE READY
9. Overvoltage detection does not have a direct influence on the state machine, it will only open the switch
