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2015-08-0009

PT0514-4

08/24/15

15

PI5USB2544

USB Charging Port Controller and Detection Power Switch

Device Operation

Please refer to the simplified device state diagram below. Power-on-reset (POR) holds device in initial state while output is held

in discharge mode. Any POR event will take the device back to initial state. After POR clears, device goes to the next state

depending on the CTL1, CTL2, CTL3 and ILIM_SEL lines as shown Figure 5.

Figure 5, PI5USB2544 Charging States

Output Discharge

To allow a charging port to renegotiate current with a portable device, PI5USB2544 uses the OUT discharge function. It

proceeds by turning off the power switch while discharging OUT, then turning back on the power switch to reassert the OUT

voltage. This discharge function is automatically applied as shown in device state diagram.

DCP Forced (DCP

Shorted or Divider-1A)

Sample

CTL Pins

Reset

Discharge

SDP1

CDP

SDP2

SDP2

(1110)

DCH

Not SDP1

CDP

(1111)

SDP1

(111x/

010x)

CDP

(1111)

SDP2

(1110)

DCH

Done

DCP_Shorted

Divider-1A

DCH/SDP/CDP

DCP Auto (DCP Shorted

/DCP-1.2V

/ Divider-1A/2A)

DCP_Shorted

/Divider-1A

DCP_Auto

DCH/SDP/CDP

Note:

1)

All shaded boxed are device charging modes.

2)

See below table for CTL settings corresponding to flow

line conditions

Device Control Pins

Flow Line Condition

CTL1 CTL2CTL3ILIM_SEL

DCH(Discharge)

0

0

0

x

CDP

1

1

1

1

SDP2(No Discharge

from/to CDP)

1

1

1

0

SDP1(Discharge

from/to any charging

state including CDP)

1

1

0

x

0

1

0

x

DCP_Short

1

0

0

x

DCP/Divider-1A

1

0

1

x

DCP_Auto

0

1

1

x

0

0

1

x

DCP_Auto

Not SDP2

or CDP