LTC3555 Datasheet, PDF (7/32 Pages) Linear Technology – High Effi ciency USB Power Manager + Triple Step-Down DC/DC

LTC3555/LTC3555-X
TYPICAL PERFORMANCE CHARACTERISTICS
Ideal Diode V-I Characteristics
1.0
INTERNAL IDEAL DIODE
WITH SUPPLEMENTAL
0.8
EXTERNAL VISHAY
Si2333 PMOS
0.6
INTERNAL IDEAL
DIODE ONLY
0.4
0.2
0
0
V_BUS = 0V
V_BUS = 5V
0.04 0.08 0.12 0.16 0.20
FORWARD VOLTAGE (V)
3555 G01
USB Limited Battery Charge
Current vs Battery Voltage
700
LTC3555
600
LTC3555-1/
LTC3555-3
500
V_BUS = 5V
R_PROG = 1k
400
R_CLPROG = 3k
300
LTC3555-3
200
100
5x USB SETTING,
0 ^{BATTERY CHARGER SET FOR 1A}
2.7 3.0 3.3 3.6 3.9 4.2
BATTERY VOLTAGE (V)
3555 G04
PowerPath Switching Regulator
Efficiency vs Output Current
100
BAT = 3.8V
1x MODE
90
5x, 10x MODE
80
70
60
50
40
0.01
0.1
OUTPUT CURRENT (A)
1
3555 G07
Ideal Diode Resistance
vs Battery Voltage
0.25
0.20
INTERNAL IDEAL
DIODE
0.15
0.10
INTERNAL IDEAL DIODE
WITH SUPPLEMENTAL
0.05
EXTERNAL VISHAY
Si2333 PMOS
0
2.7 3.0 3.3 3.6 3.9 4.2
BATTERY VOLTAGE (V)
3555 G02
USB Limited Battery Charge
Current vs Battery Voltage
150
LTC3555
125
LTC3555-1/
LTC3555-3
V_BUS = 5V
100
R_PROG = 1k
R_CLPROG = 3k
75
LTC3555-3
50
25
1x USB SETTING,
BATTERY CHARGER SET FOR 1A
0
2.7 3.0
3.3
3.6
3.9
4.2
BATTERY VOLTAGE (V)
3555 G05
Battery Charging Efficiency vs
Battery Voltage with No External
Load (P_BAT/P_BUS)
100
R_CLPROG = 3k
R_PROG = 1k
I_VOUT = 0mA
90
LTC3555-1/
LTC3555-3
80
LTC3555-3
70
60
2.7
1x CHARGING EFFICIENCY
5x CHARGING EFFICIENCY
3.0 3.3 3.6 3.9 4.2
BATTERY VOLTAGE (V)
3555 G08
Output Voltage vs Output Current
(Battery Charger Disabled)
4.50
BAT = 4V
V_BUS = 5V
5x MODE
4.25
4.00
BAT = 3.4V
3.75
3.50
3.25
0
200 400 600 800
OUTPUT CURRENT (mA)
1000
3555 G03
Battery Drain Current
vs Battery Voltage
25
I_VOUT = 0μA
20
V_BUS = 0V
15
10
V_BUS = 5V
5
(SUSPEND MODE)
0
2.7 3.0 3.3 3.6 3.9 4.2
BATTERY VOLTAGE (V)
3555 G06
V_BUS Current vs V_BUS Voltage
(Suspend)
50
BAT = 3.8V
I_VOUT = 0mA
40
30
20
10
0
0
1
2
3
4
5
BUS VOLTAGE (V)
3555 G09
3555fd
7