Datasheet

ADP5062 Data Sheet
Rev. B | Page 20 of 44
Safety Timer
While in charger mode, if the watchdog timer expires, the
ADP5062 charger initiates the safety timer, t
SAFE
(see the
Watchdog Timer section). If the processor has programmed
charging parameters by the time the charger initiates the safety
timer, the I
LIM
is set to the default value. Charging continues for
a period of t
SAFE
, and then the charger switches off and sets the
CHARGER_STATUS [2:0] bits.
Charge Complete
The ADP5062 charger monitors the charging current while
in constant voltage fast charge mode. If the current falls
below I
END
and remains below I
END
for t
END
, charging stops
and the CHDONE flag is set. If the charging current falls below
I
END
for less than t
END
and then rises above I
END
again, the t
END
timer resets.
Recharge
After the detection of charge complete, and the cessation of
charging, the ADP5062 charger monitors the BAT_SNS pin as
the battery discharges through normal use. If the BAT_SNS pin
voltage falls to V
RCH
, the charger reactivates charging. Under most
circumstances, triggering the recharge threshold results in the
charger starting directly into fast charge constant voltage mode.
The recharge function can be disabled in the I
2
C, but a status bit
(Register Address 0x0C, Bit 3) informs the system that a recharge
cycle is required.
IC Enable/Disable
The ADP5062 IC can be disabled by the DIG_IO2 digital input
pin (if factory programmed to do so) or by the I
2
C registers. All
internal control circuits are disabled when the IC is disabled. Dis-
abling the IC1 option can also control the states of the LDO FET
and the battery isolation FET.
It is critical to note that during the disable IC1 mode, a high
voltage at VINx passes to the internal supply voltage because all
of the internal control circuits are disabled. The VINx supply
voltage must fulfill the following condition:
V
ISO_Bx
< VINx < 5.5 V
Battery Charging Enable/Disable
The ADP5062 charging function can be disabled by setting the
I
2
C EN_CHG bit to low. The LDO to the system still operates
under this circumstance and can be set in I
2
C to the default or
I
2
C programmed system voltage from 4.3 V to 5.0 V (see Table 26
for details).
The ADP5062 charging function can also be controlled via one
of the external DIG_IOx pins (if factory programmed to do so).
Any change in the I
2
C EN_CHG bit takes precedence over the pin
setting.
Battery Voltage Limit to Prevent Charging
The battery monitor of the ADP5062 charger can be configured
to monitor battery voltage and prevent charging when the battery
voltage is higher than V
CHG_VLIM
(typically 3.7 V) during charging
start-up (enabled by EN_CHG or DIG_IO3). This function can
prevent unnecessary charging of a half discharged battery and,
as such, can extend the lifetime of the Li-Ion battery cell. Charging
starts automatically when the battery voltage drops below V
CHG_VLIM
and continues through full charge cycle until the battery voltage
reaches V
TRM
(typically 4.2 V).
By default, the charging voltage limit is disabled and it can be
enabled from I
2
C Register Address 0x08, Bit 5 (EN_CHG_VLIM).
SYS_EN Output
The ADP5062 features a SYS_EN open-drain FET to enable the
system until the battery is at the minimum required level for
guaranteed system start-up. When there are minimum battery
voltage and/or minimum battery charge level requirements, the
operation of SYS_EN can be set by I
2
C programming. The SYS_EN
operation can be factory programmed to four different operating
conditions as described in
Table 11.
Table 11. SYS_EN Mode Descriptions
SYS_EN Mode
Selection
Description
00
SYS_EN is activated when LDO is active and
system voltage is available.
01
SYS_EN is activated by the ISO_Bx voltage, the
battery charging mode.
10
SYS_EN is activated and the isolation FET is
disabled when the battery drops below V
WEAK
.
This option is active when VINx = 0 V and the
battery monitor is activated from Register 0x07,
Bit 5 (EN_BMON).
11
SYS_EN is active in LDO mode when the
charger is
disabled.
SYS_EN is active in charging mode when V
ISO_Bx
≥
V
WEAK
.
Indicator LED Output (ILED)
The ILED is an open-drain output for an indicator LED connec-
tion. Optionally, the ILED output can be used as a status output
for a microcontroller. Indicator LED modes are listed in Table 12.
Table 12. Indicator LED Operation Modes
ADP5062 Mode ILED Mode On/Off Time
IC Off Off
LDO Mode Off Off
LDO Mode On Off
Charge Mode Continuously on
Timer Error (t
TRK
, t
CHG
, t
SAFE
) Blinking 167 ms/833 ms
Overtemperature (T
SD
) Blinking 1 sec/1 sec