Datasheet

ADP5062 Data Sheet
Rev. B | Page 22 of 44
Figure 30. Sink Phase
Figure 31. Trickle Charge
Battery (ISO_Bx) Short Detection
A battery short occurs under a damaged battery condition or
when the battery protection circuitry is enabled.
On commencing trickle charging, the ADP5062 charger moni-
tors the battery voltage. If this battery voltage does not exceed
V
BAT_SHR
within the specified timeout period, t
BAT_SHR
, a fault is
declared and the charger is stopped by turning the battery
isolation FET off, but the system voltage is maintained at
V
ISO_STRK
by the linear regulator.
After source phase, if the ISO_Bx or BAT_SNS level remains
below V
BATH
, either the battery voltage is low or the battery node
is shorted. Because the battery voltage is low, trickle charging mode
is initiated (see Figure 31). If the BAT_SNS level remains below
V
BAT_SHR
after t
BAT_SHR
has elapsed, the ADP5062 assumes that the
battery node is shorted.
The trickle charge branch is active during the battery short
scenario, and trickle charge current to the battery is main-
tained until the 60-minute trickle charge mode timer expires.
BATTERY PACK TEMPERATURE SENSING
Battery Thermistor Input
The ADP5062 charger features battery pack temperature sensing
that precludes charging when the battery pack temperature is
outside the specified range. The THR pin provides an on and
off switching current source that should be connected directly
to the battery pack thermistor terminal. The activation interval
of the THR current source is 167 ms.
The battery pack temperature sensing can be controlled by
I
2
C, using the conditions shown in Table 13. Note that the
I
2
C register default setting for EN_THR (Register Address 0x07)
is 0 = temperature sensing off.
Table 13. THR Input Function
Conditions
THR Function VINx V
ISO_Bx
Open or V
IN
= 0 V to 4.0 V <2.5 V Off
Open or V
IN
= 0 V to 4.0 V >2.5 V Off, controlled by I
2
C
4.0 V to 6.7 V Don't care Always on
If the battery pack thermistor is not connected directly to the
THR pin, a 10 kΩ (tolerance ±20%) dummy resistor must be
connected between the THR input and GND. Leaving the THR
pin open results in a false detection of the battery temperature
being <0°C and charging is disabled.
The ADP5062 charger monitors the voltage in the THR pin and
suspends charging when the current is outside the range of less
than 0°C or greater than 60°C.
The ADP5062 charger is designed for use with an NTC thermistor
in the battery pack with a nominal room temperature value of
either 10 kΩ at 25°C or 100 kΩ at 25°C, which is selected by
factory programming.
The ADP5062 charger is designed for use with an NTC thermistor
in the battery pack with a temperature coefficient curve (beta).
Factory programming supports eight beta values covering a
range from 3150 to 4400 (see Table 43).
OPEN
ISO_Bx
SINK PHASE
LOGIC
STATUS
OPEN
OR
SHORT
t
BAT_OK
V
BATL
I
SINK
ISO_Bx
OPEN
OPEN
LOGIC
STATUS
SOURCE PHASE
t
BAT_OK
V
BATH
I
SOURCE
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I
SOURCE
SHORT
SINK PHASE
SOURCE PHASE
TRICKLE CHARGE
ISO_Bx
SHORT
ISO_Bx
SHORT
ISO_Bx
LOGIC
STATUS
OPEN
OR
SHORT
t
BAT_OK
LOGIC
STATUS
SHORT
OR
LOW
BATTERY
t
BAT_OK
LOGIC
STATUS
SHORT
t
BAT_SHR
V
BATL
V
BATH
V
BAT_SHR
I
TRK_DEAD
I
SINK
10806-031