LTC3555 Datasheet, PDF (5/32 Pages) Linear Technology – High Effi ciency USB Power Manager + Triple Step-Down DC/DC

LTC3555/LTC3555-X
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_BUS = 5V, BAT = 3.8V, DV_CC = 3.3V, R_PROG = 1k, R_CLPROG = 3k,
unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP
MAX UNITS
t_{SU_STD}
Stop Condition Time
t_{HD_DAT(OUT)}
Data Hold Time
t_{HD_DAT(IN)}
Input Data Hold Time
t_{SU_DAT}
Data Setup Time
t_LOW
Clock Low Period
t_HIGH
Clock High Period
t_f
Clock Data Fall Time
t_r
Clock Data Rise Time
t_SP
Spike Suppression Time
General Purpose Switching Regulators 1, 2 and 3
0.6
μs
225
ns
0
900
ns
100
ns
1.3
μs
0.6
μs
20
300
ns
20
300
ns
50
ns
V_IN1,2,3
V_OUTUVLO
Input Supply Voltage
V_OUT UVLO—V_OUT Falling
V_OUT UVLO—V_OUT Rising
f_OSC
Oscillator Frequency
I_FB1,2,3
FBx Input Current
D_1,2,3
Maximum Duty Cycle
R_{SW1,2,3_PD}
SWx Pull-Down in Shutdown
General Purpose Switching Regulator 1
V_IN1,2,3 Connected to V_OUT Through Low
Impedance. Switching Regulators are Disabled in
UVLO
V_FB1,2,3 = 0.85V
2.7
5.5
V
2.5
2.6
V
2.8
2.9
V
1.8 2.25
2.7
MHz
–50
50
nA
100
%
10
kΩ
I_VIN1
I_LIMSW1
I_OUT1
Pulse Skip Mode Input Current
Burst Mode Input Current
Forced Burst Mode^® Input Current
LDO Mode Input Current
Shutdown Input Current
PMOS Switch Current Limit
Available Output Current
V_FB1
V_FB1 Servo Voltage
R_P1
PMOS R_DS(ON)
R_N1
NMOS R_DS(ON)
R_{LDO_CL1}
LDO Mode Closed-Loop R_OUT
R_{LDO_OL1}
LDO Mode Open-Loop R_OUT
General Purpose Switching Regulator 2
I_OUT1 = 0μA (Note 6)
I_OUT1 = 0μA (Note 6)
I_OUT1 = 0μA (Note 6)
I_OUT1 = 0μA (Note 6)
I_OUT1 = 0μA, FB1 = 0V
Pulse Skip/Burst Mode Operation
Pulse Skip/Burst Mode Operation (Note 7)
Forced Burst Mode Operation (Note 7)
LDO Mode (Note 7)
(Note 8)
(Note 9)
225
μA
35
60
μA
20
35
μA
20
35
μA
1
μA
600 800
1100
mA
400
mA
60
mA
50
mA
l 0.78 0.80
0.82
V
0.6
Ω
0.7
Ω
0.25
Ω
2.5
Ω
I_VIN2
I_LIMSW2
I_OUT2
Pulse Skip Mode Input Current
Burst Mode Input Current
Forced Burst Mode Input Current
LDO Mode Input Current
Shutdown Input Current
PMOS Switch Current Limit
Available Output Current
I_OUT2 = 0μA (Note 6)
I_OUT2 = 0μA (Note 6)
I_OUT2 = 0μA (Note 6)
I_OUT2 = 0μA (Note 6)
I_OUT2 = 0μA, FB2 = 0V
Pulse Skip/Burst Mode Operation
Pulse Skip/Burst Mode Operation (Note 7)
Forced Burst Mode Operation (Note 7)
LDO Mode (Note 7)
225
μA
35
60
μA
20
35
μA
20
35
μA
1
μA
600 800
1100
mA
400
mA
60
mA
50
mA
Burst Mode is a registered trademark of Linear Technology Corporation.
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