DS2777G+ Maxim Integrated Products, DS2777G+ Datasheet - Page 19

• Manufacturer Part Number: DS2777G+
• Description: IC FUEL GAUGE LI+ 2CELL 14-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2777G+

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4 V ~ 9.2 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 13. Top-Level Algorithm Diagram
The full curve defines how the full point of a given cell
depends on temperature for a given charge termina-
tion. The application’s charge termination method
should be used to determine the table values. The
DS2775–DS2778 reconstruct the full line from cell char-
acteristic table values to determine the full capacity of
the battery at each temperature. Reconstruction occurs
in one-degree temperature increments.
Protector and Optional SHA-1 Authentication
2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
VOLTAGE
TEMPERATURE
CURRENT
ACCUMULATED
CURRENT (ACR) (RW)
AVERAGE CURRENT
AGING CAPACITY (AC)
(2 BYTES EE)
AGE SCALAR (AS)
(1 BYTE EE)
SENSE-RESISTOR PRIME (RSNSP)
(1 BYTE EE)
CHARGE VOLTAGE (VCHG)
(1 BYTE EE)
MINIMUM CHARGE CURRENT (IMIN)
(1 BYTE EE)
ACTIVE-EMPTY VOLTAGE (VAE)
(1 BYTE EE)
ACTIVE-EMPTY CURRENT (IAE)
(1 BYTE EE)
CELL MODEL PARAMETERS
______________________________________________________________________________________
(EEPROM)
(R)
(R)
(R)
(R)
AVAILABLE CAPACITY CALCULATION
Full
ACR HOUSEKEEPING
CAPACITY LOOKUP
LEARN FUNCTION
AGE ESTIMATOR
The active-empty curve defines the variation of the
active-empty point over temperature. The active-empty
point is defined as the minimum voltage required for
system operation at a discharge rate based on a high-
level load current (one that is sustained during a high-
power operating mode). This load current is
programmed as the active-empty current (IAE), and
should be a 3.5s average value to correspond to values
FULL
ACTIVE EMPTY
STANDBY EMPTY SE(T)
REMAINING ACTIVE-ABSOLUTE
CAPACITY (RAAC) mAh
REMAINING STANDBY-ABSOLUTE
CAPACITY (RSAC) mAh
REMAINING ACTIVE-RELATIVE
CAPACITY (RARC) %
REMAINING STANDBY-RELATIVE
CAPACITY (RSRC) %
CYCLE COUNTER (EEPROM)
USER MEMORY (EEPROM)
16 BYTES
FULL(T)
AE(T)
Active Empty
(R)
(R)
(R)
(R)
(R)
(R)
(R)
19