DS2790G+T&R Maxim Integrated Products, DS2790G+T&R Datasheet - Page 31

• Manufacturer Part Number: DS2790G+T&R
• Description: IC FUEL GAUGE BATT 28-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2790G+T&R

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 11. Current Register Format
Figure 12. Average Current Register Format
Current Offset Correction
Continuous offset cancellation is performed automatically to correct for offsets in the current measurement system.
Individual values reported by the Current register have a maximum offset of ±0.5 bits (±7.8125µV). Individual
values reported in the Average Current register have a maximum offset of ±4 bits (±7.8125µV).
Current Accumulation
The DS2790 measures current for coulomb-counting purposes, with an accuracy of ±2% ±3.9µV over a range of
±64mV. Using a 15mΩ sense resistor, current accumulation is performed over a range of ±4.26A while measuring
standby currents with an accuracy of ±195µA. Current measurements are internally summed, or accumulated, with
the results displayed in the Accumulated Current Register (ACR). The accuracy of the ACR is dependent on both
the current measurement and the accumulation timebase. The 16-bit ACR has a range of ±204.8mVh with a
resolution of 6.25µVh. Accumulation of charge current above the maximum register value is reported at the
maximum value; conversely, accumulation of discharge current below the minimum register value is reported at the
minimum value. Read and write access is allowed to the ACR.
Figure 13. Accumulated Current Register Format
The lower 32 bits of ACR resolution (bits 2
6008h respectively. Note that since the lower bits are from separate address words it cannot be guaranteed that
they will contain data from the same measurement as the main ACR register at the time of reading. However, two
consecutive reads from addresses 6006h–6008h that contain the same data esures that all data is from the same
measurement. When the ACR register is written, the lower ACR bits are automatically cleared.
12-bit + sign resolution (13-bit), 88ms update interval
15-bit + sign resolution (16-bit), 2.8s update interval
MSb
“S”: sign bit(s)
MSb
“S”: sign bit(s)
“S”: sign bit(s)
MSb
S
S
S
2
2
2
11
14
14
2
2
2
10
13
13
2
2
2
12
12
9
2
2
2
11
11
8
2
2
2
10
10
7
-1
Word Address 6004h
Word Address 6009h
Word Address 6006h
to 2
2
2
2
6
9
9
-32
) can be read by firmware from address locations 6007h and
31 of 41
2
2
2
5
8
8
2
2
2
4
7
7
2
2
2
3
6
6
2
2
2
2
5
5
2
2
2
1
4
4
2
2
2
Units: 2
Units: 2
Units: 2
0
3
3
2
2
X
0
0
2
2
0
= 15.625μV/R
= 1.953μV/R
= 6.25μVh/R
2
2
X
1
1
LSb
LSb
LSb
2
2
X
0
SNS
0
SNS
sns