BQ77910A Datasheet, PDF (42/52 Pages) Texas Instruments – Multi-Cell Lithium-Ion/Polymer Precision Protector

bq77910A
SLUSAV6 – FEBRUARY 2012
UVT[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
UV Trip Level
(Volts)
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
UVT[3:0]
1000
1001
1010
1011
1100
1101
1110
1111
UV Trip Level
(Volts)
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
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UV Detection Configuration #2 (UV_CFG2, Address 0x05)
Bit
7
Number
Bit Name
UV_REC
If 0
Recover from UV fault when all cell voltages increase above
V_UV threshold+hyst. CHG FET enabled immediately if
charger detected
If 1
Recover from UV fault only when all cell voltages increase
above V_UV threshold+hyst AND load is removed.
6
UV_REC_DLY
Part does NOT enter SHUTDOWN mode from
the UV fault state
Part does enter SHUTDOWN mode if any cell
voltage remains <V_UV+hyst for >8 seconds in
the UV fault state
5
4
3
2
1
0
UVH1 UVH0 RSVD10 UVD2 UVD1 UVD0
1 of 4 possible
values, see
table below
NOT
USED
NOT
USED
1 of 8 possible values,
binary spacing, see
following table.
UV Hysteresis Level
The UV hysteresis is set using UVH[1:0] bits. Four possible values are available as shown; however, the
maximum recovery level is set to 3.5 V in the case of a combination of high UV trip point plus high UV hysteresis
values.
UVH[1:0]
00
01
10
11
Hysteresis (Volts)
0.4
0.8
1.2
1.6
Recovery Voltage (Combination of UVT + UVH settings)
UV Trip Level
0.4 V
Hysteresis
0.8 V
1.2 V
1.4
1.8
2.2
2.6
1.5
1.9
2.3
2.7
1.6
2.0
2.4
2.8
1.7
2.1
2.5
2.9
1.8
2.2
2.6
3.0
1.9
2.3
2.7
3.1
2.0
2.4
2.8
3.2
2.1
2.5
2.9
3.3
2.2
2.6
3.0
3.4
2.3
2.7
3.1
3.5
2.4
2.8
3.2
3.5
2.5
2.9
3.3
3.5
2.6
3.0
3.4
3.5
2.7
3.1
3.5
3.5
2.8
3.2
3.5
3.5
2.9
3.3
3.5
3.5
1.6 V
3.0
3.1
3.2
3.3
3.4
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
42
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