DS2746G+ Maxim Integrated Products, DS2746G+ Datasheet - Page 11

• Manufacturer Part Number: DS2746G+
• Description: IC MON BATTERY 2-WIRE 10-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2746G+

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion); Nickel-Metal Hydride (NiMH)
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-WFDFN Exposed Pad
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: No
• Mounting Style: SMD/SMT
• Temperature Monitoring: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 3. Accumulated Current Range for Various RSNS Values
CURRENT OFFSET BIAS
The Current Offset Bias register (COBR) allows a programmable offset value to be added to raw current
measurements. The result of the raw current measurement plus the COBR value is displayed as the current
measurement result in the CURRENT register, and is used for current accumulation. The COBR value can be used
to correct for a static offset error, or can be used to intentionally skew the current results and therefore the current
accumulation.
Read and write access is allowed to COBR. Whenever the COBR is written, the new value is applied to all
subsequent current measurements. COBR can be programmed in 1.56V steps to any value between +198V and
-200V. The COBR value is stored as a two’s complement value in volatile memory, and must be initialized via the
interface on power-up. Figure 10 describes the COBR address, format, and resolution.
Figure 10. Current Offset Bias Register Format
CURRENT BLANKING
The Current Blanking feature modifies current measurement result prior to being accumulated in the ACR. Current
Blanking occurs conditionally when a current measurement (raw current + COBR) falls in one of two defined
ranges. The first range prevents charge currents less than 100V/R
prevents discharge currents less than 25V/R
always performed, however, discharge current blanking must be enabled by setting the NBEN bit in the
Status/Config register. See the register description for additional information.
ACCUMULATION BIAS
The Accumulation Bias register (ABR) allows a programmable offset value to be added to the current accumulation
process. The new ACR value results from the addition of the Current register value plus ABR plus the previous
ACR value. ABR can be used to intentionally skew the current accumulation to estimate system stand-by currents
that are too small to measure. ABR value is not subject to the Current Blanking thresholds.
Read and write access is allowed to the ABR. Whenever the ABR is written, the new value is applied to all
subsequent current measurements. ABR can be set to any value between +193.75V and -200V in 6.25V steps.
The ABR value is stored as a two’s complement value in volatile memory, and must be initialized via the interface
on power-up. The lower two bits of the ABR register have no effect on the data. Figure 11 describes the ABR
address, format, and resolution.
409.6mVh
V
SS
- V
SNS
20.48Ah
20m
MSb
“S”: sign bit
S
2
ACR RANGE
6
SNS
27.31Ah
2
15m
in magnitude from being accumulated. Charge current blanking is
5
Address 61h
11 of 17
2
4
R
2
SNS
Units: 1.56V/Rsns
3
40.96Ah
10m
2
2
SNS
2
from being accumulated. The second range
1
LSb
2
0
81.92Ah
5m