BQ25120A Datasheet, PDF (19/67 Pages) Texas Instruments – Low IQ Highly Integrated Battery Charge Management Solution for Wearables and IoT

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Feature Description (continued)
/CD
/MR
VIN
Shipmode
I2C
Write
t > t_RESET
t_QUIET
bq25120A
SLUSD08 – MAY 2017
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Figure 16. CD, MR and VIN Sequencing for Ship Mode Entry Through Long MR button press
The end user can enable the device (exit Ship Mode) by connecting an adapter to IN (V_IN > V_BAT + V_SLP) or by
toggling the MR button. Note that in the case where an adapter is connected while the MR is still held low and
immediately after the RESET timer has expired (MR low for t_RESET), the device will not enter Ship Mode, but may
enter it upon adapter removal (Same behavior as setting the EN_SHIPMODE bit when the adapter is present).
This will not be the case if MR has gone high when the adapter is connected or MR continues to be held low for
a period longer than t_WAKE1 after the adapter is connected.
To exit Ship Mode through and MR press the battery voltage must be above the maximum programmable
BUVLO threshold when V_IN is not present. Once MR goes low, the device will start to exit Ship Mode, powering
PMID. The device will not complete the transition from Ship Mode until MR has been held low for at least t_WAKE1.
Only after the transition is complete may the host start I²C communication if the device has not entered High
Impedance Mode.
9.3.2 High Impedance Mode
High Impedance mode is the lowest quiescent current state while operating from the battery. During Hi-Z mode
the SYS output is powered by BAT, the MR input is active, and the LSCTRL input is active. All other circuits are
in a low power or sleep state.The LS/LDO output can be enabled in Hi-Z mode with the LSCTRL input. If the
LS/LDO output has been enabled through I²C prior to entering Hi-Z mode, it will stay enabled. The CD pin is
used to put the device in a high-impedance mode when battery is present and V_IN < V_UVLO. Drive CD high to
enable the device and enter active battery operation when V_IN is not valid. When the HZ_MODE bit is written by
the host, the I²C interface is disabled if only battery is present. To resume I²C, the CD pin must be toggled. If the
supply for the CD pull up glitches or experiences a brownout condition , it is recommended to toggle the /CD pin
to resume I²C communication.. The functionality of the pin is shown in Table 1.
CD, State
L
H
Table 1. CD, State Table
V_IN < V_UVLO
Hi-Z
Active Battery
V_IN > V_UVLO
Charge Enabled
Charge Disabled
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