LTC3577-4_15 Datasheet, PDF (7/52 Pages) Linear Technology – Highly Integrated Portable Product PMIC

LTC3577-3/LTC3577-4
ELECTRICAL CHARACTERISTICS Step-Down Switching Regulators. The l denotes the specifications
which apply over the full operating temperature range, otherwise specifications are at T_A = 25°C. V_OUT = V_IN12 = V_IN3 = 3.8V, all
regulators enabled unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
Step-Down Switching Regulators (Buck1, Buck2 and Buck3)
V_IN12, V_IN3 Input Supply Voltage
(Note 9)
l 2.7
5.5
V
V_OUT UVLO
V_OUT Falling
V_OUT Rising
V_IN12 and V_IN3 Connected to V_OUT Through
2.5
2.7
V
Low Impedance. Switching Regulators are
2.8
2.9
V
Disabled Below V_OUT UVLO
f_OSC
Oscillator Frequency
1.91
2.25
2.59
MHz
800mA Step-Down Switching Regulator 3 (Buck3-Enabled via EN3, Disabled in PON and POFF States)
I_VIN3Q
Pulse-Skipping Mode Input Current
Burst Mode Operation Input Current
(Note 10)
(Note 10)
100
μA
20
35
μA
Shutdown Input Current
EN3 = 0
0.01
1
μA
I_LIM3
Peak PMOS Current Limit
V_FB3
Feedback Voltage
(Note 7)
Pulse-Skipping Mode
Burst Mode Operation
1000
1400
1700
mA
l 0.78
0.8
0.82
V
l 0.78
0.8
0.824
V
I_FB3
FB3 Input Current
D3
Max Duty Cycle
(Note 10)
FB3 = 0V
–0.05
100
0.05
μA
%
R_P3
R_DS(ON) of PMOS
R_N3
R_DS(ON) of NMOS
R_{SW3_PD}
SW3 Pull-Down in Shutdown
EN3 = 0
V_IL,EN3
EN3 Input Low Voltage
V_IH,EN3
EN3 Input High Voltage
500mA Step-Down Switching Regulator 2 (Buck2-Pushbutton Enabled, Third in Sequence)
0.3
Ω
0.4
Ω
10
kΩ
0.4
V
1.2
V
I_VIN12Q
Pulse-Skipping Mode Input Current
Burst Mode Operation Input Current
(Note 10)
(Note 10)
100
μA
20
μA
Shutdown Input Current
POFF State
0.01
1
μA
I_LIM2
Peak PMOS Current Limit
V_FB2
Feedback Voltage
(Note 7)
Pulse-Skipping Mode
Burst Mode Operation
650
900
1200
mA
l 0.78
0.8
0.82
V
l 0.78
0.8
0.824
V
I_FB2
FB2 Input Current
D2
Max Duty Cycle
(Note 10)
FB2 = 0V
–0.05
100
0.05
μA
%
R_P2
R_DS(ON) of PMOS
I_SW2 = 100mA
R_N2
R_DS(ON) of NMOS
I_SW2 = –100mA
R_{SW2_PD}
SW2 Pull-Down in Shutdown
POFF State
500mA Step-Down Switching Regulator 1 (Buck1-Pushbutton Enabled, Second in Sequence)
0.6
Ω
0.6
Ω
10
kΩ
I_VIN12Q
Pulse-Skipping Mode Input Current
Burst Mode Operation Input Current
(Note 10)
(Note 10)
100
μA
20
μA
Shutdown Input Current
0.01
1
μA
I_LIM1
Peak PMOS Current Limit
V_FB1
Feedback Voltage
(Note 7)
Pulse-Skipping Mode
Burst Mode Operation
650
900
1200
mA
l 0.78
0.8
0.82
V
l 0.78
0.8
0.824
V
I_FB1
FB1 Input Current
D1
Max Duty Cycle
(Note 10)
FB1 = 0V
–0.05
100
0.05
μA
%
R_P1
R_N1
R_{SW1_PD}
R_DS(ON) of PMOS
R_DS(ON) of NMOS
SW1 Pull-Down in Shutdown
I_SW1 = 100mA
I_SW1 = –100mA
POFF State
0.6
Ω
0.6
Ω
10
kΩ
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