Datasheet

LTC3523/LTC3523-2
4
3523fb
TYPICAL PERFORMANCE CHARACTERISTICS
Normalized FBx Reference vs
Temperature
Inrush Current Control for the
Step-Up Converter
Inrush Current Control for the
Step-Down Converter
Load Transient Response Step-Up
Load Transient Response
Step-Down
Current Limit vs Temperature
R
DS(ON)
vs Input Voltage for the
Step-Down Converter
Normalized Oscillator Frequency
vs Temperature
TEMPERATURE (°C)
–45 –25 –5
NORMALIZED FBx VOLTAGE (V)
1.00000
1.00125
75
3523 G01
0.99875
0.99500
0.99750
0.99625
15 35 55
TEMPERATURE (°C)
–45 –25 –5
NORMALIZED FREQUENCY (Hz)
1.00
1.05
75
3523 G02
0.95
15 35 55
V
OUT_BCK
1V/DIV
I
L_BCK
200mA/DIV
200μs/DIV
3523 G04
V
OUT
= 1.2V
V
IN
= 2.4V
C
OUT
= 10μF
L1 = 4.7μH
SHDN2
2V/DIV
OUTPUT
RIPPLE
20mV/DIV
LOAD
CURRENT
20mA/DIV
500μs/DIV
3523 G05
V
OUT
= 3.3V
V
IN
= 2.4V
C
OUT
= 10μF
L1 = 4.7μH
20mA TO 70mA STEP
OUTPUT
RIPPLE
20mV/DIV
LOAD
CURRENT
20mA/DIV
500μs/DIV
3523 G06
V
OUT
= 1.2V
V
IN
= 2.4V
C
OUT
= 47μF
L1 = 4.7μH
C
F
= 68pF
10mA TO 30mA STEP
R
DS(ON)
vs Output Voltage for the
Step-Up Converter
TEMPERATURE (°C)
–45
CURRENT LIMIT (A)
0.8
1.0
1.2
35 75
3523 G07
0.6
0.4
–25 –5 15
55
0.2
0
BOOST CURRENT
LIMIT
BUCK CURRENT
LIMIT
INPUT VOLTAGE (V)
1
R
DS(ON)
(Ω)
0.40
0.60
5
3523 G08
0.20
0
2
3
4
1.5
2.5
3.5
4.5
0.80
0.30
0.50
0.10
0.70
PMOS
NMOS
OUTPUT VOLTAGE (V)
1
0
R
DS(0N)
(Ω)
0.05
0.15
0.20
0.25
0.50
0.35
2
3
3.5
3532 G09
0.10
0.40
0.45
0.30
1.5 2.5
4
4.5
5
PMOS
NMOS
(T
A
= 25°C unless otherwise noted)
V
OUT_BST
2V/DIV
I
L_BST
200mA/DIV
SHDN1
2V/DIV
200μs/DIV
3523 G03
V
OUT
= 3.3V
V
IN
= 2.4V
C
OUT
= 10μF
L1 = 4.7μH