LTC3553-2_15 Datasheet, PDF (8/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger, Always-On LDO and Buck Regulator

LTC3553-2
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise specified.
V_FLOAT Load Regulation
4.204
4.202
V_BUS = 5V
HPWR = H
4.200
4.198
4.196
4.194
4.192
0
50 100 150 200 250 300 350 400 450
I_BAT (mA)
35532 G10
Forward Voltage
vs Ideal Diode Current
300
250
V_BUS = 5V
200
150
V_BUS = 0V
100
50
0
0 200 400 600 800 1000 1200
I_BAT (mA)
35532 G13
Switching from 100mA Mode to
500mA Mode
Battery Regulation (Float)
Voltage vs Temperature
4.250
V_BUS = 5V
I_BAT = 2mA
4.225
4.200
4.175
4.150
–75 –50 –25 0 25 50 75 100 125
TEMPERATURE (°C)
35532 G11
V_BUS Connect Waveform
V_BUS
5V
V_OUT
3.8V
LDO (3.3V)
BUCK (1.2V)
0V
V_BAT = 3.8V
I_LDO = 100mA
I_BUCK = 100mA
HPWR = HIGH
SUSP = LOW
STBY = LOW
20μs/DIV
35532 G14
Switching from Suspend Mode to
500mA Mode
5V
HPWR
0
I_BUS
0.5A/DIV
0A
I_BAT
0.5A/DIV 0A
V_BAT = 3.75V
I_OUT = 50mA
R_PROG = 2k
SUSP = LOW
1ms/DIV
5V
SUSP
0
5V
V_{OUT 0}
I_BUS
0.5A/DIV
0A
I_BAT
0.5A/DIV
0A
35532 G16
V_BAT = 3.75V
I_OUT = 50mA
R_PROG = 2k
HPWR = HIGH
1ms/DIV
35532 G17
8
Battery Charge Current
vs Battery Voltage
500
V_BUS = 5V
HPWR = H
400 ^{RPROG = 1.87k}
300
200
100
0
2
2.4 2.8 3.2 3.6 4 4.4
V_BAT (V)
35532 G12
V_BUS Disconnect Waveform
V_BUS
5V
V_OUT
3.8V
0V
V_OUT
LDO (3.3V)
BUCK (1.2V)
V_BUS
V_BAT = 3.8V
I_LDO = 100mA
I_BUCK = 100mA
HPWR = HIGH
SUSP = LOW
STBY = LOW
100μs/DIV
Oscillator Frequency
vs Temperature
1.30
2.7V
3.8V
1.25
5.5V
1.20
35532 G15
1.15
1.10
1.05
1.00
0.95
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
35532 G18
35532f