DS2764 High-Precision Li+ Battery Monitor With 2-Wire Interface
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ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE
(2.5V V
DD
5.5V, T
A
= -20C to +70C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SCL Clock Frequency
f
SCL
(Note 12) 0 100 KHz
Bus Free Time Between a STOP
and START Condition
t
BUF
4.7 µs
Hold Time (Repeated)
START Condition
t
HD:STA
(Note 13) 4.0 µs
Low Period of SCL Clock
t
LOW
4.7 µs
High Period of SCL Clock
t
HIGH
4.0 µs
Setup Time for a Repeated
START Condition
t
SU:STA
4.7 µs
Data Hold Time
t
HD:DAT
(Note 14, 15) 0 5.0 µs
Data Setup Time
t
SU:DAT
(Note 14) 250 ns
Rise Time of both SDA and
SCL Signals
t
R
1000 ns
Fall Time of both SDA and
SCL Signals
t
F
300 ns
Setup Time for STOP
Condition
t
SU:STO
4.0 µs
Spike pulse widths suppressed by
input filter
t
SP
(Note 16) 0 50 ns
Capacitive Load for each Bus
Line
C
B
(Note 17) 400 pF
SCL, SDA Input Capacitance C
BIN
60 pF
EEPROM RELIABILITY SPECIFICATION
(2.5V V
DD
5.5V, T
A
= -20C to +70C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Copy to EEPROM Time t
EEC
2 10 ms
EEPROM Copy Endurance N
EEC
(Note 11) 25,000 cycles
Note 1: All voltages are referenced to V
SS
.
Note 2: See the Selector Guide section to determine the corresponding part number for each V
OV
value.
Note 3: Internal current-sense resistor configuration.
Note 4: External current-sense resistor configuration.
Note 5: Self-heating due to output pin loading and sense resistor power dissipation can alter the reading from ambient conditions.
Note 6: Compensation of the internal sense resistor value for initial tolerance and temperature coefficient of -20°C to +70°C can reduce
the maximum reportable magnitude to 1.9A.
Note 7: Current offset error null to ±1 LSB typically requires 3.5s in-system calibration by user.
Note 8: Current gain error specification applies to gain error in converting the voltage difference at IS1 and IS2, and excludes any error
remaining after the DS2764 compensates for the internal sense resistor’s temperature coefficient of 3700ppm/C to an accuracy
of 500ppm/C. The DS2764 does not compensate for external sense resistor characteristics, and any error terms arising from
the use of an external sense resistor should be taken into account when calculating total current measurement error.
Note 9: Accuracy at time of shipment from Dallas Semiconductor is 3% max. Board mounting processes may cause the current gain
error to widen to as much as 10% for devices with the internal sense resistor option. Contact factory for on-board recalibration
procedure devices with the internal sense resistor option to improve accuracy.
Note 10: Typical value for t
ERR1
is specified at 3.6V and +25°C, max value is specified for 0°C to +50°C. Max value for t
ERR2
is specified
for -20°C to +70°C.
Note 11:
Four-year data retention at +70C.
Note 12:
Timing must be fast enough to prevent the DS2764 from entering sleep mode due to bus low for period >
t
SLEEP
Note 13: f
SCL
must meet the minimum clock low time plus the rise/fall times.
