Datasheet

LTC1760
7
1760fa
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IH_MODE
MODE Input High Voltage (V
IH
)V
VCC2
= 4.85V
l
V
VCC2
• 0.7 V
MODE Input Current (I
IH
) MODE = V
VCC2
• 0.7V, V
VCC2
= 4.85V
l
–1 1 μA
MODE Input Current (I
IL
) MODE = V
VCC2
• 0.3V, V
VCC2
= 4.85V
l
–1 1 μA
Charger Timing
t
TIMEOUT
Timeout for Wake-Up Charging and
Controlled Charging
l
140 175 210 sec
t
QUERY
Sampling Rate Used by the LTC1760 to
Update Charging Parameters
1 sec
SMBus Timing
SCL Serial-Clock High Period(t
HIGH
) At I
PULLUP
= 350μA, C
LOAD
= 150pF (Note 8)
l
4μs
SCL Serial-Clock Low Period (t
LOW
) At I
PULLUP
= 350μA, C
LOAD
= 150pF (Note 8)
l
4.7 μs
SDA/SCL Rise Time (t
r
)C
LOAD
= 150pF, RPU = 9.31k (Note 8)
l
1000 ns
SDA/SCL Fall Time (t
f
)C
LOAD
= 150pF, RPU = 9.31k (Note 8)
l
300 ns
SMBus Accelerator Trip Voltage Range
l
0.8 1.42 V
Start-Condition Setup Time (t
SU:STA
)
l
4.7 μs
Start-Condition Hold Time (t
HD:STA
)
l
4μs
SDA to SCL Rising-Edge
Setup Time (t
SU:DAT
)
l
250 ns
SDA to SCL Falling-Edge Hold Time,
Slave Clocking in Data (t
HD:DAT
)
l
300 ns
t
TIMEOUT_
SMB
The LTC1760 will Release the SMBus
and Terminate the Current Master or
Slave Command if the Command is not
Completed Before this Time
l
25 35 ms
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
junction temperature range, otherwise specifi cations are at T
A
= 25°C (Note 6). V
DCIN
= 20V, V
BAT1
= 12V, V
BAT2
= 12V, V
VDDS
= 3.3V,
V
VCC2
= 5.2V unless otherwise noted.
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Battery voltage must be adequate to drive gates of PowerPath
P-channel FET switches. This does not affect charging voltage of the
battery, which can be zero volts during wake-up charging.
Note 3: DCIN, BAT1, BAT2 are held at 12V and GDCI, GB1I, GB2I are
forced to 10.5V. SCP is set at 12V to measure source current at GDCI,
GB1I and GB2I. SCP is set at 11.9V to measure sink current at GDCI, GB1I
and GB2I.
Note 4: Extrapolated from testing with C
L
= 50pF.
Note 5: Accuracy dependent upon external sense resistor and
compensation components.
Note 6: The LTC1760 is tested under pulsed load conditions such that T
J
≈
T
A
. The LTC1760C is guaranteed to meet specifications from 0°C to 70°C
junction temperature. Specifications over the –40°C to 85°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC1760I is guaranteed
over the –40°C to 125°C operating junction temperature range.
Note 7: Charger servos to the value reported by a Voltage() query. This is
the internal cell voltage measured by the battery electronics and may be
lower than the terminal voltage. Refer to “Operation Section 3.7” for more
information.
Note 8: C
LOAD
is the combined capacitance on the host’s SMBus
connection and the selected battery’s SMBus connection.
Note 9: C
LOAD_MAX
is the maximum allowed combined capacitance on
THxA, THxB and the battery’s SafetySignalx connections.
Note 10: Does not include current supplied by V
CC
to V
CC2
(I
VCC2_AC1
or
I
VCC2_AC0
)
Note 11: Measured with thermistors not present, R
VLIMIT
and R
ILIMIT
removed and SMBALERT = 1. See Applications Information section:
“Calculating IC Operating Current” for example on how to calculate total IC
operating current.
Note 12: Requested currents below 44mV/R
SENSE
may not servo correctly
due to charger offsets. The charging current for requested currents below
4mV/R
SENSE
will be between 4mV/R
SENSE
and (Requested Current – 8mA).
Refer to Applications Information: “Setting Charger Output Current Limit”
for values of R
SENSE
.
Note 13: This limit is greater than the absolute maximum for the charger.
Therefore, there is no effective limitation for the voltage when this option
is selected.
Note 14: Does not apply to Wake-Up Mode.