LTC3550-1_15 Datasheet, PDF (7/24 Pages) Linear Technology – Dual Input USB/AC Adapter Li-Ion Battery Charger with 600mA Buck Converter

LTC3550-1
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C, unless otherwise noted.
Undervoltage Lockout Threshold
vs Temperature
4.25
4.20
DCIN UVLO
4.15
4.10
4.05
4.00
USBIN UVLO
3.95
3.90
3.85
–50
–25 0 25 50
TEMPERATURE (°C)
75 100
3550-1 G19
Charge Current During Turn-On
and Turn-Off
I_BAT
500mA/DIV
ENABLE
5V/DIV
V_DCIN = 5V
R_IDC = 1.25k
100µs/DIV
3550-1 G22
Buck Regulator Output Voltage
vs Temperature
1.91
V_CC = 3.6V
1.90 ^{IOUT = 100mA}
1.89
1.88
1.87
1.86
1.85
1.84
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3550-1 G25
Recharge Threshold Voltage
vs Temperature
4.16
4.14
4.12
V_DCIN = V_USBIN = 4.3V
4.10
V_DCIN = V_USBIN = 8V
4.08
4.06
4.04
–50
–25 0 25 50
TEMPERATURE (°C)
75 100
3550-1 G20
Buck Regulator Efficiency vs V_CC
100
95
I_OUT = 100mA
90
I_OUT = 10mA
85
80
I_OUT = 600mA
75
70
2
3
4
V_CC (V)
5
6
35501 G23
Oscillator Frequency
vs Temperature
1.70
V_CC = 3.6V
1.65
1.60
1.55
1.50
1.45
1.40
1.35
1.30
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3550-1 G26
Battery Drain Current
vs Temperature
5
V_BAT = 4.2V
V_DCIN, V_USBIN (NOT CONNECTED)
4
3
2
1
0
–1
–50 –25 0
25 50
TEMPERATURE (°C)
75 100
3550-1 G21
Buck Regulator Efficiency
vs Output Current
100
V_CC = 2.7V
90
V_CC = 4.2V
80
70
V_CC = 3.6V
60
50
0.1
1
10
100
1000
I_LOAD (mA)
35501 G24
Oscillator Frequency vs V_CC
1.8
1.7
1.6
1.5
1.4
1.3
1.2
2
3
4
5
6
V_CC (V)
3550-1 G27
35501f
7