LTC3552 Datasheet, PDF (7/24 Pages) Linear Technology – Standalone Linear Li-Ion Battery Charger and Dual Synchronous Buck Converter

LTC3552
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C Unless Otherwise Specified.
Switching Regulator
Reference Voltage
vs Temperature
0.615
V_CC = 3.6V
0.610
0.605
0.600
0.595
0.590
0.585
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3552 G20
R_DS(ON) vs V_CC
500
450
400
MAIN
SWITCH
350
300
SYNCHRONOUS
250
SWITCH
200
12
3
4
5
V_CC (V)
6
7
3552 G21
R_DS(ON) vs Junction Temperature
550
V_CC = 2.7V
500
450
V_CC = 4.2V ^{VCC = 3.6V}
400
350
300
250
200
150
MAIN SWITCH
100
SYNCHRONOUS SWITCH
–50 –25 0 25 50 75 100 125 150
JUNCTION TEMPERATURE (°C)
3552 G22
Efficiency vs Load Current
100
95
90 Burst Mode OPERATION
85
80
75
70
65
60
1
PULSE-SKIPPING MODE
V_CC = 3.6V, V_OUT = 1.8V
NO LOAD ON OTHER
REGULATOR; REGULATOR 1;
CIRCUIT OF FIGURE 2
10
100
LOAD CURRENT (mA)
1000
3552 G23
Load Regulation
2.0
1.5
Burst Mode OPERATION
1.0
0.5
0
PULSE-SKIPPING MODE
–0.5
–1.0
–1.5
–2.0
1
V_CC = 3.6V, V_OUT = 1.8V
NO LOAD ON OTHER REGULATOR
REGULATOR 1; CIRCUIT OF FIGURE 2
10
100
LOAD CURRENT (mA)
1000
3552 G24
Line Regulation
0.5
0.4
V_OUT = 1.8V
I_OUT = 200mA
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
2
3
4
5
6
V_CC (V)
3552 G25
Efficiency vs Load Current
100
V_CC = 3.6V ^VCC ^{= 2.7V}
90
V_CC = 4.2V
80
70
60
V_OUT = 2.5V, REGULATOR 1
50 Burst Mode OPERATION, MODE/SYNC = 3.6V
NO LOAD ON OTHER REGULATOR
CIRCUIT OF FIGURE 2
40
1
10
100
1000
LOAD CURRENT (mA)
3552 G26
Efficiency vs Load Current
100
95
90
V_CC = 3.6V
V_CC = 2.7V
85
80
V_CC = 4.2V
75
70 _{VOUT = 1.5V, REGULATOR 1}
65
Burst Mode OPERATION, MODE/SYNC = 3.6V
NO LOAD ON OTHER REGULATOR
60 ^{CIRCUIT OF FIGURE 2}
1
10
100
1000
LOAD CURRENT (mA)
3552 G27
Efficiency vs Load Current
100
95
90
85 ^{VCC = 2.7V}
V_CC = 3.6V
80
75 ^{VCC = 4.2V}
70 _{VOUT = 1.2V, REGULATOR 1}
65
Burst Mode OPERATION, MODE/SYNC = 3.6V
NO LOAD ON OTHER REGULATOR
60 ^{CIRCUIT OF FIGURE 2}
1
10
100
1000
LOAD CURRENT (mA)
3552 G28
3552f
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