Datasheet

3
LTC3445
3445fa
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC1
= V
CC2
= 3.6V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
S
Additional Input DC Bias Current For Buck (Note 4)
Active Mode V
OUT
= 90%, I
LOAD
= 0A 220 µA
Sleep Mode V
OUT
= 103%, I
LOAD
= 0A 6 µA
f
OSC
Nominal Oscillator Frequency V
OUT
= 100% ● 1.2 1.5 1.8 MHz
V
OUT
= 0V 300 kHz
R
PFET
R
DS(ON)
of P-Channel FET I
SW
= 100mA 0.45 Ω
R
NFET
R
DS(ON)
of N-Channel FET I
SW
= –100mA 0.325 Ω
I
LSW
SW Leakage V
RUN
= 0V, V
SW
= 0V or 5V, V
CC1
= 5V 1 µA
LDO1
I
S
Additional DC Bias for LDO1 23 30 µA
V
OUT
Regulated Output Voltage 2.5V < V
IN
< 5.5V, 1mA < I
LOAD
< 50mA 0.582 V
CC2
–V
0.3
Line Regulation ∆V
CC2
= 2.5V to 5.5V, I
LOAD
= 1mA, V
OUT
= 1.2V 1 5 mV
Load Regulation V
CC2
= 2.5V, ∆I
LOAD
= 1mA to 50mA, V
OUT
= 1.2V 15 mV
Dropout Voltage I
LOAD
= 50mA 0.3 V
V
FB
LDO Feedback Voltage I
LOAD
= 0mA ● 0.582 0.6 0.618 V
LDO2
I
S
Additional DC Bias for LDO2 23 30 µA
V
OUT
Regulated Output Voltage 2.5V < V
IN
< 5.5V, 1mA < I
LOAD
< 50mA 0.582 V
CC2
–V
0.3
Line Regulation ∆V
CC2
= 2.5V to 5.5V, I
LOAD
= 1mA, V
OUT
= 1.2V 1 5 mV
Load Regulation V
CC2
= 2.5V, ∆I
LOAD
= 1mA to 50mA, V
OUT
= 1.2V 15 mV
Dropout Voltage I
LOAD
= 50mA 0.3 V
V
FB
LDO Feedback Voltage I
LOAD
= 0mA ● 0.582 0.6 0.618 V
PowerPath Controller
V
TRACK
Tracked Input Voltage 3V
CC1
–V
0.2
V
TRACK
– Tracked Output Voltage at V
CC
BATT 3V < V
TRACK
< V
CC1
– 0.2V –0.2 0 0.2 V
V
CC
BATT
V
BACKUP
Backup Battery Voltage 2 5.5 V
I
BACKUP
Backup Battery Bias Current V
CC1
= V
TRACK
= 0V, V
BACKUP
= 2.5V 4 6.5 µA
V
CC
BATT V
CC
BATT Output V
TRACK
= 0V, V
CC1
= 4V, I
VCCBAT
= 8mA 2.85 3 3.1 V
I
VCCBATT
Max V
CC
BATT Output Current V
CC1
= 2.5V 8 mA
BATTFAULT V
CC1
High Level (Good) Where BATTFAULT Goes High 2.65 2.8 2.9 V
V
CC1
Low Level (Bad) Where BATTFAULT Goes Low 2.4 2.5 2.6 V
Hysteresis V
CC1
= 0V to 4.2V, 4.2 to 0V 0.3 V
I
2
C Interface
f
I2C(MAX)
Maximum I
2
C Operating Frequency (Note 5) 400 kHz
t
BUF
Bus Free Time Between Stop and Start (Note 5) 1.3 µs
Condition
t
HD(RSTA)
Hold Time After (Repeated) (Note 5) 600 ns
Start Condition