Texas Instruments BQ25123, Manual

Page: 24 / 72

IN (COLD) (HOT)
(COLD) (HOT)
(LO)
IN IN
(HOT) (COLD)
(HOT) (COLD)
1 1
V x R x R x
V V
R =
V V
R x 1 R x 1
V V
æ ö
ç ÷ -
ç ÷
è ø
æ ö æ ö
ç ÷ ç ÷ - - -
ç ÷ ç ÷
è ø è ø (1)
IN
(COLD)
(HI)
(LO) (COLD)
V
1
V
R =
1 1
+
R R
æ ö
ç ÷ -
ç ÷
è ø
æ ö
ç ÷
ç ÷
è ø
(2)
Where
• R
(HOT)
= the NTC resistance at the hot temperature
• R
(COLD)
= the NTC resistance at the cold temperature
The warm and cool thresholds are not independently programmable. The cool and warm NTC resistances for a
selected resistor devider are calculated using
Equation 3 and Equation 4 .
( )
( )
( )
( )
( )
( )
COOL%
COOL% COOL%
(LO) (HI)
(COOL)
(LO) (LO) (HI)
R x R x V
R =
R R x V R x V
- -
(3)
( )
( )
( )
( )
( )
( )
(LO) (HI)
WARM%
(WARM)
(LO) (LO) (HI)
WARM% WARM%
R x R x V
R =
R R x V R x V
- -
(4)
BQ25123
SLUSCZ6A – JANUARY 2018 – REVISED MAY 2021
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