MAX17043G+T Maxim Integrated Products, MAX17043G+T Datasheet - Page 8

• Manufacturer Part Number: MAX17043G+T
• Description: IC 2-WIRE FG MODEL GAUGE LO BATT
• Manufacturer: Maxim Integrated Products
• Series: ModelGauge™r

Specifications of MAX17043G+T

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 2.5 V ~ 4.5 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 90-2771G+BTR

Compact, Low-Cost 1S/2S Fuel Gauges
with Low-Battery Alert
Battery voltage is measured at the CELL pin input with
respect to GND over a 0 to 5.00V range for the
MAX17043 and 0 to 10.00V for the MAX17044 with reso-
lutions of 1.25mV and 2.50mV, respectively. The A/D
calculates the average cell voltage for a period of
125ms after IC POR and then for a period of 500ms for
every cycle afterwards. The VCELL register requires
500ms to update after exiting Sleep mode. The result is
placed in the VCELL register at the end of each conver-
sion period. Figure 3 shows the VCELL register format.
The SOC register is a read-only register that displays
the state of charge of the cell as calculated by the
ModelGauge algorithm. The result is displayed as a
percentage of the cell’s full capacity. This register
automatically adapts to variation in battery size since
the MAX17043/MAX17044 naturally recognize relative
SOC. Units of % can be directly determined by observ-
ing only the high byte of the SOC register. The low byte
provides additional resolution in units 1/256%. The
reported SOC also includes residual capacity, which
might not be available to the actual application because
of early termination voltage requirements. When SOC()
= 0, typical applications have no remaining capacity.
The first update occurs 125ms after POR of the IC.
Subsequent updates occur at variable intervals
depending on application conditions. ModelGauge cal-
culations outside the register are clamped at minimum
and maximum register limits. Figure 4 shows the SOC
register format.
Figure 3. VCELL Register Format
Figure 4. SOC Register Format
8
MSB
MSB
2
2
_______________________________________________________________________________________
11
7
2
2
10
6
0: BITS ALWAYS READ LOGIC 0
2
2
9
5
MSB—ADDRESS 02h
MSB—ADDRESS 04h
2
2
8
4
VCELL Register
2
2
7
3
SOC Register
2
2
6
2
2
2
5
1
LSB
LSB
2
2
4
0
The MODE register allows the host processor to send
special commands to the IC (Table 2). Valid MODE reg-
ister write values are listed as follows. All other MODE
register values are reserved.
The VERSION register is a read-only register that con-
tains a value indicating the production version of the
MAX17043/MAX17044.
The CONFIG register compensates the ModelGauge
algorithm, controls the alert interrupt feature, and forces
the IC into Sleep mode through software. The format of
CONFIG is shown in Figure 5.
CONFIG is an 8-bit value that can be adjusted to opti-
mize IC performance for different lithium chemistries or
different operating temperatures. Contact Maxim for
instructions for optimization. The power-up default
value for CONFIG is 97h.
Table 2. MODE Register Commands
MSB
MSB
2
2
VALUE
-1
3
4000h
2
2
-2
2
UNITS: 1.25mV FOR MAX17043
COMMAND
Quick-Start
2
2
2.50mV FOR MAX17044
-3
1
LSB—ADDRESS 03h
LSB—ADDRESS 05h
2
2
-4
0
VERSION Register
CONFIG Register
See the Quick-Start
description section.
2
0
MODE Register
-5
DESCRIPTION
2
0
-6
UNITS: 1.0%
2
0
-7
CONFIG
LSB
LSB
2
0
-8