DS2778 Maxim Integrated Products, DS2778 Datasheet - Page 28

• Manufacturer Part Number: DS2778
• Description: 2-Cell Stand-Alone Li+ Fuel-Gauge IC
• Manufacturer: Maxim Integrated Products

2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
Protector and Optional SHA-1 Authentication
The 8-bit Overvoltage Threshold register (VOV) sets the overvoltage threshold for the protection circuitry. An over-
voltage condition is detected if either of the voltages on V
the VOV register is 2 x 5V/1024 = 31.25mV. The V
Example:
Table 5. VOV Register Programmability
28
BIT 7
______________________________________________________________________________________
VOV[6:0] BIT FIELD
X
0 0 0 0 0 0 0
0 0 0 0 0 0 1
0 0 0 0 0 1 0
0 0 0 0 0 1 1
0 0 0 0 1 0 0
0 0 0 0 1 0 1
0 0 0 0 1 1 0
0 0 0 0 1 1 1
0 0 0 1 0 0 0
0 0 0 1 0 0 1
0 0 0 1 0 1 0
0 0 0 1 0 1 1
0 0 0 1 1 0 0
0 0 0 1 1 0 1
0 0 0 1 1 1 0
0 0 0 1 1 1 1
...
BIT 6
VOV6
V
OV
= (678 + 2 x Overvoltage_Threshold_Register_Value) x 5V/1024
Overvoltage Threshold register = 1110110b = 118D
BIT 5
VOV5
V
OV
3.311
3.320
3.330
3.340
3.350
3.359
3.369
3.379
3.389
3.398
3.408
3.418
3.428
3.438
3.447
3.457
V
= (678 + 2 x 118) x 5V/1024 = 4.46289V
...
OV
BIT 4
VOV4
OV
set point can be calculated by the following formula.
Overvoltage Threshold Register Format
IN1
or V
BIT 3
VOV3
IN2
VOV[6:0] BIT FIELD
Overvoltage Threshold Register (7Fh)
exceeds the OV threshold for t
1 1 1 0 0 0 0
1 1 1 0 0 0 1
1 1 1 0 0 1 0
1 1 1 0 0 1 1
1 1 1 0 1 0 0
1 1 1 0 1 0 1
1 1 1 0 1 1 0
1 1 1 0 1 1 1
1 1 1 1 0 0 0
1 1 1 1 0 0 1
1 1 1 1 0 1 0
1 1 1 1 0 1 1
1 1 1 1 1 0 0
1 1 1 1 1 0 1
1 1 1 1 1 1 0
1 1 1 1 1 1 1
BIT 2
VOV2
BIT 1
VOV1
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OVD
4.404
4.414
4.424
4.434
4.443
4.453
4.463
4.473
4.482
4.492
4.502
4.512
4.521
4.531
4.541
4.551
V
OV
. The LSB of
BIT 0
VOV0