Cfg_S0_S1 - Analog Devices LINEAR LT8491 Manual

LT8491
2
I C REGISTER DESCRIPTIONS
This register is used to set V
dition. V is a percentage of the Stage 2 voltage V
S0_UV
via the CFG_CHRG_MISC→TC_ENABLE bit, V
CFG_S0_UV is an 8-bit unsigned integer, representing a percentage of V
follows:
⎡
CFG_S0_UV = 200 •
⎢
⎣
Example: Presume that V
⎡
CFG_S0_UV = 200 •
⎣ ⎢
= 200 •[50%]
= 100 (decimal)
= 0x64 (hexadecimal)
Therefore, writing CFG_S0_UV to 0x64 configures V
percentage than CFG_UV_S0 to achieve threshold hysteresis and avoid oscillating between stages. A 4%, or more,
difference is recommended
Note: CFG_UV_S0 and CFG_S0_UV allow the charger to start even if there is a battery protection circuit in between
the V terminal and the battery. Setting both registers to 0x00 ensures that the charger can start and will not enter
BAT
fault, even if the initial V
BAT
Related Data Sheet Sections: Charging Faults, Battery Charging Algorithm, HW Config: V
Temp. Compensation

CFG_S0_S1

2
I C REG
ADDRESS BIT(S) UNITS
0x3E [7:0] 200 • (% of V
This register is used to set V
current charging. V
S0_S1
is enabled, via the CFG_CHRG_MISC→TC_ENABLE bit, V
CFG_S0_S1 is an 8-bit unsigned integer, representing a percentage of V
follows:
⎡ V
CFG_S0_S1= 200 •
⎢
⎣
48
, the falling V
S0_UV BAT
S0_UV
V ⎤
S0 _UV
•100%
⎥
V
⎦
S2
is set to 14.2V and we wish to configure V
S2
7.1V
⎤
•100%
⎦ ⎥
14.2V
voltage is 0.
FORMAT EXAMPLES
) Unsigned 70% = 0x8C
S2
Integer 55.5% = 0x6F
, the rising V threshold to exit Stage 0 trickle charging and enter Stage 1 constant-
S0_S1 BAT
is a percentage of the Stage 2 voltage V
⎤
S0 _ S1
•100%
⎥
V
⎦
S2
For more information
threshold to exit Stage 0 charging and enter the low V
. Therefore, if Stage 2 temperature compensation is enabled,
S2
will vary with temperature in proportion to V
S2
S0_UV
to be 50% of V . Be sure to set CFG_S0_UV to a lower V
S0_UV S2
MIN VALUE MAX VALUE DESCRIPTION
0% = 0x00 90% = 0xB4 Configure V
0.5% per bit.
. Therefore, if Stage 2 temperature compensation
S2
will vary with temperature in proportion to V
S0_S1
S2
www.analog.com
.
S2
between 0% to 90% and is calculated as
= 7.1V. Set CFG_S0_UV as follows:
in Stage 2 (V
BAT
voltage as percentage of V
S0_S1
between 0% - 90% and is calculated as
fault con-
BAT
S2
), Configure
S2
. Precision of
S2
.
S2
Rev. 0