AN4308 Datasheet, PDF (7/14 Pages) STMicroelectronics – The STCCxxxx devices also integrate the autodetect feature that supports both DCP

AN4308
Application dependent CTLx controlling options
2.3
CTLx pins controlled by signals SUSPEND and
AC_ADAPTER
In this case, the charging modes are enabled only when the system is powered from AC
adapter.
Table 6. SUSPEND and AC_ADAPTER control truth table
Power state
CTL1 = CTL2 = SUSPEND CTL3 = AC_ADAPTER
Mode
S0
1
S0
1
S3/S4/S5
0
S3/S4/S5
0
0
SDP
1
CDP
1
DCP auto
0
OFF
The drawback of this solution is that it doesn't support remote wakeup in the S3.
Another way may be to use a GPIO from EC to control the CTL2.
Table 7. SUSPEND, AC_ADAPTER and GPIO control truth table
Power state CTL1 = SUSPEND CTL2 = GPIO
CTL3 =
AC_ADAPTER
Mode
S0
1
1
0
SDP
S0
1
1
1
CDP
S3
0
1
0
SDP
S3
0
1
1
LS devices: remote wakeup.
FS, HS devices: DCP auto.
S4/S5
0
0
1
DCP auto
S4/S5
0
0
0
OFF
Or to use 1 GPIO only and the CTL3 pulled-up^(b):
Power state
S0
S3
S4/S5
Table 8. SUSPEND and GPIO control truth table
CTL1 =
SUSPEND
CTL2 = GPIO CTL3 pull-up
Mode
1
1
1
CDP
0
1
1
LS devices: remote wakeup.
FS, HS devices: DCP auto.
0
0
1
DCP auto
The device can be powered on/off using the EN pin.
b. Internal pull-up on the CTL3 is a metal option, not implemented in current versions of STCCxxxx devices.
DocID024781 Rev 1
7/14
14