Datasheet

LTC4070
5
4070fc
Typical perForMance characTerisTics
Hot Plug Transient, C
C
= 330µF,
R
IN
= 81Ω
Step Response with 800mAHr
Battery, R
IN
= 81Ω
V
OH
LBO/HBO vs I
SOURCE
V
OL
LBO/HBO vs I
SINK
Power Spectral Density
T
A
= 25°C, unless otherwise noted.
I
SOURCE
(mA)
V
CC
– V
OH
(V)
2.5
1.5
2.0
1.0
0.5
0
1.50.5 1.0
0
2.0
4070 G10
2.5 3.0
LBO
V
CC
= 3.1V
HBO
V
CC
= V
F
– 25m
I
SINK
(mA)
V
OL
(V)
2.5
1.5
2.0
1.0
0.5
0
42
0
6
4070 G11
8 10
V
CC
= 3.7V
4ms/DIV
4070 G13
CH1 = V
IN
(2V/DIV)
CH2 = V
CC
(2V/DIV)
CH3 = V
HBO
(2V/DIV)
CH4 = I
IN
(10mA/DIV)
400ns/DIV
CH1 = V
IN
(2V/DIV)
CH2 = V
CC
(2V/DIV)
CH3 = V
HBO
(2V/DIV)
CH4 = I
IN
(10mA/DIV)
4070 G14
FREQUENCY (Hz)
PSD (µV
RMS
/√Hz)
35
25
30
20
15
10
5
0
101 100
0
1000 10000
4070 G12
100000
C
C
= 10µF, I
CC
= 1mA, 1Hz Res
Bandwidth, Noise = 1.0452mV
RMS
from 10Hz to 100kHz
pin FuncTions
NTCBIAS (Pin 1): NTC Bias Pin. Connect a resistor from
NTCBIAS to NTC, and a thermistor from NTC to GND. Float
NTCBIAS when not in use. Minimize parasitic capacitance
on this pin.
NTC (Pin 2): Input to the Negative Temperature Coefficient
Thermistor Monitoring Circuit. The NTC pin connects to
a negative temperature coefficient thermistor which is
typically co-packaged with the battery to determine the
temperature of the battery. If the battery temperature is too
high, the float voltage is reduced. Connect a low drift bias
resistor from NTCBIAS to NTC and a thermistor from NTC
to GND. When not in use, connect NTC to V
CC
. Minimize
parasitic capacitance on this pin.
ADJ (Pin 3): Float Voltage Adjust Pin. Connect ADJ to GND
to program 4.0V float voltage. Disconnect ADJ to program
4.1V float voltage. Connect ADJ to V
CC
to program 4.2V
float voltage. The float voltage is also adjusted by the NTC
thermistor.