DS2764 High-Precision Li+ Battery Monitor With 2-Wire Interface

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ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE

(2.5V

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

SCL Clock Frequency

fSCL

(Note 12)

0

100

KHz

Bus Free Time Between a STOP

and START Condition

tBUF

4.7

µs

Hold Time (Repeated)

START Condition

tHD:STA

(Note 13)

4.0

µs

Low Period of SCL Clock

tLOW

4.7

µs

High Period of SCL Clock

tHIGH

4.0

µs

Setup Time for a Repeated

START Condition

tSU:STA

4.7

µs

Data Hold Time

tHD:DAT

(Note 14, 15)

0

5.0

µs

Data Setup Time

tSU:DAT

(Note 14)

250

ns

Rise Time of both SDA and

SCL Signals

tR

1000

ns

Fall Time of both SDA and

SCL Signals

tF

300

ns

Setup Time for STOP

Condition

tSU:STO

4.0

µs

Spike pulse widths suppressed by

input filter

tSP

(Note 16)

0

50

ns

Capacitive Load for each Bus

Line

CB

(Note 17)

400

pF

SCL, SDA Input Capacitance

60

pF

EEPROM RELIABILITY SPECIFICATION

(2.5V

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Copy to EEPROM Time

2

10

ms

EEPROM Copy Endurance

(Note 11)

25,000

cycles

Note 1:

Note 2:

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. Flip-chip board mounting processes may cause the

current gain error to widen to as much as 10% for flip chip devices with the internal sense resistor option. Contact factory for

on-board recalibration procedure for flip chip devices with the internal sense resistor option to improve accuracy.

Note 10:

for -20°C to +70°C.

Note 11:

Four-year data retention at +70

°C.

Note 12:

Timing must be fast enough to prevent the DS2764 from entering sleep mode due to bus low for period >

Note 13: