LTC2941
4
2941fb
For more information www.linear.com/LTC2941
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 2)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
SU,DAT(MIN)
Minimum Data Set-Up Time Input
l
100 ns
t
HD,DATI(MIN)
Minimum Data Hold Time Input
l
0 µs
t
HD,DATO
Data Hold Time Output
l
0.3 0.9 µs
t
Of
Data Output Fall Time (Notes 6, 7)
l
20 + 0.1
• C
B
300 ns
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: All currents into pins are positive, all voltages are referenced to
GND unless otherwise specified
Note 3: I
SUPPLY
= I
SENSE
+
+ I
SENSE
Note 4: The equivalent charge of an LSB in the accumulated charge
registers (C, D) depends on the value of R
SENSE
and the setting of the
internal prescaling factor M. It is calculated by:
q
LSB
= 0.085mAh
50m
Ω
R
SENSE
M
128
See Choosing R
SENSE
and Coulomb Counter Prescaler M section for more
information.
1mAh = 3.6A • s = 3.6C (coulomb), 0.085mAh = 306mC.
Note 5: Deviation of q
LSB
from its nominal value.
Note 6: C
B
= capacitance of one bus line in pF (10pF ≤ C
B
≤ 400pF).
Note 7: Guaranteed by design, not subject to test.
Timing Diagram
t
SU, DAT
t
SU, STO
t
SU, STA
t
BUF
t
HD, STA
t
HD, DATO,
t
HD, DATI
t
HD, STA
START
CONDITION
STOP
CONDITION
REPEATED START
CONDITION
START
CONDITION
SDA
SCL
2941 F01
t
of
Figure 1. Definition of Timing on I
2
C Bus
LTC2941
5
2941fb
For more information www.linear.com/LTC2941
Typical perFormance characTerisTics
Total Charge Error
vs Differential Sense Voltage
Total Charge Error
vs Supply Voltage
Total Charge Error vs Temperature
Supply Current vs Supply Voltage
Shutdown Supply Current
vs Supply Voltage
V
SENSE
(mV)
0.1
–1
CHARGE ERROR (%)
0
–2
2
1
1 10 100
2941 G01
–3
3
V
SENSE
+ = 2.7V
V
SENSE
+ = 4.2V
V
SENSE
+
(V)
2.5
CHARGE ERROR (%)
–1.00
–0.50
–0.25
0
1.00
0.25
3.5
4.5
5.0
2941 G02
–0.75
0.50
0.75
3.0
4.0
5.5
6.0
V
SENSE
= –50mV
V
SENSE
= –10mV
TEMPERATURE (°C)
–50
CHARGE ERROR (%)
–1.00
–0.50
–0.25
0
0.50
25
50
2941 G03
–0.75
0.75
1.00
0.25
–25 0
75
100
V
SENSE
= –50mV
V
SENSE
= –10mV
V
SENSE
+
(V)
2.5
SUPPLY
80
90
4.0 5.0
2941 G04
70
60
3.0 3.5
4.5 5.5 6.0
50
40
T
A
= 25°C
T
A
= –40°C
T
A
= 85°C
V
SENSE
+
(V)
2.5
0
I
SHUTDOWN
(µA)
1.0
2.0
3.5
4.5
5.0
2941 G05
0.5
1.5
3.0
4.0
5.5
6.0
T
A
= 25°C
T
A
= –40°C
T
A
= 85°C
LTC2941
6
2941fb
For more information www.linear.com/LTC2941
pin FuncTions
SENSE
+
(Pin 1): Positive Current Sense Input and Power
Supply. Connect to the load/charger side of the sense
resistor. V
SENSE
+
operating range is 2.7V to 5.5V.
GND (Pin 2): Device Ground. Connect directly to the nega-
tive battery terminal.
SCL (Pin 3):
Serial Bus Clock Input.
SDA (Pin 4/Pin 6):
Serial Bus Data Input and Output.
AL/CC (Pin 5/Pin 7): Alert Output or Charge Complete
Input. Configured either as an SMBus alert output or
charge complete input by control register bits B[2:1].
At power-up, the pin defaults to alert mode conforming
to the SMBus alert response protocol. It behaves as an
open-drain logic output that pulls to GND when a value
in the threshold registers is exceeded.
When configured as a charge complete input, connect
to the charge complete output from the battery charger
circuit. A high level at CC sets the value of the accumulated
charge (registers C, D) to FFFFh.
SENSE
(Pin 6/Pin 8): Negative Current Sense Input. Con-
nect SENSE
to the positive battery terminal side of the
sense resistor. The voltage between SENSE
and SENSE
+
must remain within ±50mV in normal operation.
Exposed Pad (Pin 7/Pin 9): Do not connect.
block Diagram
REF CLK
BIDIRECTIONAL
INTEGRATOR
SENSE
INTERNAL
REFERENCE
GENERATOR
ACCUMULATED
CHARGE
REGISTER
PRESCALER
M
STATUS/
CONTROL
REGISTER
INTERNAL
OSCILLATOR
SENSE
+
V
SUPPLY
AL/CC
AL
GND
I
2
C/
SMBus
SCL
CC
SDA
2941 F02
Figure 2. Block Diagram of the LTC2941

LTC2941IDCB#TRMPBF

Mfr. #:
Manufacturer:
Analog Devices / Linear Technology
Description:
Battery Management Bat Gas Gauge w/ I2C Int
Lifecycle:
New from this manufacturer.
Delivery:
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