Datasheet

LTC3577/LTC3577-1
6
3577fa
ELECTRICAL CHARACTERISTICS
I
2
C Interface. The l denotes the specifi cations which apply over the full
operating temperature range, otherwise specifi cations are at T
A
= 25°C. DV
CC
= 3.3V, V
OUT
= 3.8V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DV
CC
Input Supply Voltage 1.6 5.5 V
I
DVCC
DV
CC
Supply Current SCL = 400kHz
SCL = SDA = 0kHz
1
0.4
µA
µA
V
DVCC,UVLO
DV
CC
UVLO 1.0 V
V
IH
Input HIGH Voltage 50 70 %DV
CC
V
IL
Input LOW Voltage 30 50 %DV
CC
I
IH
Input HIGH Leakage Current SDA = SCL = DV
CC
= 5.5V –1 1 µA
I
IL
Input LOW Leakage Current SDA = SCL = 0V, DV
CC
= 5.5V –1 1 µA
V
OL
SDA Output LOW Voltage I
SDA
= 3mA 0.4 V
Timing Characteristics (Note 8) (All Values are Referenced to V
IH
and V
IL
)
f
SCL
SCL Clock Frequency 400 kHz
t
LOW
LOW Period of the SCL Clock 1.3 µs
t
HIGH
HIGH Period of the SCL Clock 0.6 µs
t
BUF
Bus Free Time Between Stop and Start Condition 1.3 µs
t
HD,STA
Hold Time After (Repeated) Start Condition 0.6 µs
t
SU,STA
Setup Time for a Repeated Start Condition 0.6 µs
t
SU,STO
Stop Condition Setup Time 0.6 µs
t
HD,DATO
Output Data Hold Time 0 900 ns
t
HD,DATI
Input Data Hold Time 0 ns
t
SU,DAT
Data Setup Time 100 ns
t
SP
Input Spike Suppression Pulse Width 50 ns
Step-Down Switching Regulators. The l denotes the specifi cations which apply over the full operating temperature range,
otherwise specifi cations 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
Low Impedance. Switching Regulators are
Disabled Below V
OUT
UVLO
2.5 2.7
2.8 2.9
V
V
f
OSC
Oscillator Frequency 1.91 2.25 2.59 MHz
800mA Step-Down Switching Regulator 3 (Buck3 – Pushbutton Enabled, Third in Sequence)
I
VIN3Q
Pulse-Skipping Mode Input Current (Note 10) 100 µA
Burst Mode Operation Input Current (Note 10) 17 µA
Shutdown Input Current 0.01 µA
I
LIM3
Peak PMOS Current Limit (Note 7) 1000 1400 1700 mA
V
FB3
Feedback Voltage Pulse-Skipping Mode
Burst Mode Operation
l
l
0.78
0.78
0.8
0.8
0.82
0.824
V
V
I
FB3
FB3 Input Current (Note 10) –0.05 0.05 µA
D3 Max Duty Cycle FB3 = 0V 100 %
R
P3
R
DS(ON)
of PMOS 0.3 Ω
R
N3
R
DS(ON)
of NMOS 0.4 Ω