Dialog DA9318, User Manual

Page: 8 / 27

UM-PM-022
DA9318 Direct Charging Reference Board
User Manual Revision 1.0 1-Mar-2017
CFR0012
8 of 27
© 2017 Dialog Semiconductor
4.5 Direct Charging Sequence
A sequence diagram for direct charging is depicted in Figure 4 .
NOTE
The DA9318 direct charging reference board communication to the TA is achieved using a Dialog proprietary
secondary-side to primary-side digital link communication protocol. The sequence diagram in
Figure 4 is
provided for information only. Please contact ic-support@diasemi.com for more information.
DA9318 TA
Main
Charger
Read (VBAT)
loop
PC
Power
Monitor
TA
Control
nPG=
’0'
Read VBAT
Configure target VBUS
based on BATT
Write (TARG_VBUS)
TA Control implements first BCS
signaling and then attempts setting
VBUS via QC or AFC signalling
Set (VBUS)
Done
Read (VBUS)
If VBUS rises to the
target value, direct
charging is continued
nCE=
’1'
CP_EN=
’1'
loop
Read (IIN)
Direct charging begins
Read (VBUS)
Write (TARG_VBUS)
Write (TARG_ILIM)
As VBAT rises the output voltage of the
TA is increased. After the target VBAT
is hit the current limit of the TA is step-
wise reduced
Set (VBUS)
loop
Direct charging ends
CP_EN=
’0'
nCE=
’0'
Set (ILIM)
The TA ramps up
the voltage
Write (TARG_ILIM)
Set (ILIM)
The main charger
starts charging
automatically
The main charger
handles the rest of the
charging cycle
Read (VBAT)
Battery connected
Mini USB connected
TA connected
Figure 4: Sequence Diagram for Direct Charging