LTC4100EGPBF LINER [Linear Technology], LTC4100EGPBF Datasheet - Page 24

• Manufacturer Part Number: LTC4100EGPBF
• Description: Smart Battery Charger Controller
• Manufacturer: LINER [Linear Technology]

LTC4100
APPLICATIONS INFORMATION
24
b) I
b1) I
b2) I
sampling that will vary with the presence of DC power
being on or off. DCDIV is detected every 32ms. RTHX
is the value of the safety signal resistance, which will
vary with temperature or battery confi guration.
I
where RTHX > 100k
I
RTHX > 30k
I
I
where RTHX < 3k
*= includes underrange
rate is reduced to every 250ms or less.
I
where RTHX > 100K
I
+ 1/1000 • V
where RTHX > 30K
I
1/500 • V
+ RTHX)
I
1/500 • V
RTHX)
where RTHX < 3k
* includes underrange
THRM
THRM(ON)
THRM(ON)_OVERRANGE
THRM(ON)_COLD
THRM(ON)_NORMAL
THRM(ON)_HOT
THRM(OFF)
THRM(OFF)_OVERRANGE
THRM(OFF)_COLD
THRM(OFF)_NORMAL
THRM(OFF)_HOT
current is due to SafetySignal (thermistor pin)
DD
DD
when DC is on:
when DC is off, the thermistor monitoring
/(54.9k + RTHX) + 1/1000 • V
/(54.9k + RTHX) + 1/500 • V
DD
* = 1/8 • V
* = 1/50 • V
/(54.9k + RTHX)
= 1/8 • V
= 1/50 • V
+ 1/8 • V
= 1/8 • V
= 1/50 • V
+ 1/16 • V
= 1/16 • V
= 1/50 • V
DD
DD
DD
DD
DD
/(54.9k + RTHX)
/(54.9k + RTHX) where
DD
/(1.13k + RTHX)
/(54.9k + RTHX)
DD
/(54.9k + RTHX) +
/(54.9k + RTHX)
DD
DD
/(54.9k + RTHX) +
DD
/(1.13k + RTHX)
/(54.9k + RTHX)
/(54.9k + RTHX)
DD
DD
/(1.13k +
/(1.13k
Complete Examples
1) Battery thermistor = 400Ω, V
2) Battery thermistor = 10kΩ, V
c) I
Battery mode (DC is off), SMBus activity is 10kHz
and a 2% SMBus duty cycle, which represents a
suspended or sleep condition of a notebook.
I
Battery mode and a 10% SMBus duty cycle, which
represents an active notebook at idle.
I
DCIN = ON and a 20% SMBus duty cycle which
represents an active notebook charging.
I
Battery mode (DC is off), SMBus activity is 10kHz
and a 2% SMBus duty cycle:
I
Battery mode and a 10% SMBus duty cycle:
I
DCIN = ON and a 20% SMBus duty cycle:
I
This directly depends on the SMBus frequency, duty
cycle of messages sent on the SMBus and how long
it takes to drive the SMBus to V
I
TOTAL
TOTAL
TOTAL
TOTAL
TOTAL
TOTAL
ACCEL
ACCEL
= I
= I
= I
= I
= I
= I
= I
is the current used by the SMBus accelerators.
+ 5.26μA + 2.44μA = 130μA
+ 5.26μA + 12.2μA = 207μA
+ 215.6μA + 24.4μA = 514μA
+ 2.14μA + 2.44μA = 126μA
+ 2.14μA + 12.2μA = 204μA
+ 37.7μA + 24.4μA = 336μA
Message Duty Cycle •V
RUN
RUN
RUN
RUN
RUN
RUN
PULL-UP
+ I
+ I
+ I
+ I
+ I
+ I
THRM(OFF)
THRM(OFF)
THRM(ON)
THRM(OFF)
THRM(OFF)
THRM(OFF)
• 2 • SMBus Frequency •
+ I
+ I
+ I
+ I
+ I
+ I
ACCEL
ACCEL
ACCEL
ACCEL
ACCEL
ACCEL
DD
DD
DD
DD
= 5.0V
= 5.0V
= 274μA
/2.25V• Rise Time
.
= 121.9μA
= 189.5μA
= 121.9μA
= 189.5μA
= 274μA
4100fb