DS2788E+ Maxim Integrated Products, DS2788E+ Datasheet - Page 11

• Manufacturer Part Number: DS2788E+
• Description: IC FUEL GAUGE W/DSP DRV 14TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of DS2788E+

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-TSSOP
• Product: Fuel Gauges
• Operating Supply Voltage: 2.5 V to 4.5 V
• Supply Current: 70 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: Yes
• Mounting Style: SMD/SMT
• Temperature Monitoring: Yes
• Uvlo Start Threshold: 2.4 V
• Uvlo Stop Threshold: 2.5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The current blanking feature modifies the current mea-
surement result prior to being accumulated in the ACR.
Current blanking occurs conditionally when a current
measurement (raw current + COB) falls in one of two
defined ranges. The first range prevents charge cur-
rents less than 100µV from being accumulated. The
second range prevents discharge currents less than
25µV in magnitude from being accumulated. Charge-
current blanking is always performed, however, dis-
charge-current blanking must be enabled by setting
the NBEN bit in the Control register. See the register
description for additional information.
Figure 9. Fractional/Low Accumulated Current Register (ACRL) Format
Figure 10. Accumulation Bias Register Formats
AB
ACRL
“X”: reserved
MSb
2
11
2
10
2
______________________________________________________________________________________
9
MSB—ADDRESS 12h
±409.6mVh
V
V
SS
6.25μVh
SS
2
- V
- V
8
SNS
SNS
Current Blanking
2
7
MSb
“S”: SIGN BIT(S)
S
2
312.5μAh
±20.48Ah
6
Stand-Alone Fuel-Gauge IC with
20m
20m
2
6
2
5
2
5
LSb
2
ADDRESS 61h
4
ACR RANGE
2
416.7μAh
±27.30Ah
ACR LSb
4
15m
15m
2
The Accumulation Bias (AB) register allows an arbitrary
bias to be introduced into the current-accumulation
process. The AB can be used to account for currents
that do not flow through the sense resistor, estimate
currents too small to measure, estimate battery self-dis-
charge, or correct for static offset of the individual
DS2788 device. The AB register allows a user-pro-
grammed positive or negative constant bias to be
included in the current accumulation process. The
user-programmed two’s complement value, with bit
weighting the same as the Current register, is added to
the ACR once per current conversion cycle. The AB
value is loaded on power-up from EEPROM memory.
Figure 10 shows the format of the AB register.
3
MSb
UNITS: 1.5625μV/R
2
R
R
3
SNS
SNS
2
2
LED Display Drivers
±40.96Ah
2
625μAh
2
10m
10m
2
1
2
1
LSB—ADDRESS 13h
2
LSb
SNS
0
2
0
1.250mAh
Accumulation Bias
±81.92Ah
5m
5m
X
UNITS: 1.526nVhr/R
X
READ ONLY
X
LSb
SNS
X
EE
11