LTC3554 Datasheet, PDF (9/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

LTC3554
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise specified.
Step-Down Switching Regulator
Short-Circuit Current
vs Temperature
500
Step-Down Switching Regulator
Output Transient (STBY = H)
480
V_OUT2
20mV/DIV
(AC)
460
440
420
400
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3554 G19
Step-Down Switching Regulator
Output Transient (STBY = L)
V_OUT1
100mV/DIV
(AC)
150mA
I_OUT1
5mA
V_OUT1 = 3.3V
200μs/DIV
3554 G27
Step-Down Switching
Regulator Feedback Voltage
vs Output Current
0.820
3.8V
0.815 ^5V
0.810
0.805
0.800
0.795
0.790
0.785
0.780
0.1
1
10
100
OUTPUT CURRENT (mA)
1000
3554 G21
5mA
I_OUT2
10μA
V_OUT2 = 1.2V
50μs/DIV
3554 G26
Step-Down Switching
Regulator Switch Impedance
vs Temperature
1.6 _{BVIN = 3.2V}
1.4
PMOS
1.2
1.0
NMOS
0.8
0.6
0.4
0.2
0
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3554 G20
Step-Down Switching Regulator
Start-Up Waveform
V_OUT2
50mV/DIV
(AC)
V_OUT1
1V/DIV
0V
I_L1
100mA/DIV
0mA
PWR_ON1
V_OUT2 = 1.2V
I_OUT2 = 50mA
R_OUT1 = 22Ω
100μs/DIV
3554 G28
3554p
9