Datasheet

3
LTC3718
3718fa
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
IN1
= 15V, V
IN2
= 1.5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
RUN/SS(LT)
RUN Pin Latchoff Threshold RUN/SS Pin Falling 3.5 4.2 V
I
RUN/SS(C)
Soft-Start Charge Current V
RUN/SS
= 0V –0.5 –1.2 –3 µA
I
RUN/SS(D)
Soft-Start Discharge Current V
RUN/SS
= 4.5V, V
FB
= 0V 0.8 1.8 3 µA
V
IN(UVLO)
V
IN1
Undervoltage Lockout V
IN
Falling ● 3.4 3.9 V
V
IN
Rising ● 3.5 4.0 V
TG R
UP
TG Driver Pull-Up On Resistance TG High 2 3 Ω
TG R
DOWN
TG Driver Pull-Down On Resistance TG Low 2 3 Ω
BG R
UP
BG Driver Pull-Up On Resistance BG High 3 4 Ω
BG R
DOWN
BG Driver Pull-Down On Resistance BG Low 1 2 Ω
TG t
r
TG Rise Time C
LOAD
= 3300pF 20 ns
TG t
f
TG Fall Time C
LOAD
= 3300pF 20 ns
BG t
r
BG Rise Time C
LOAD
= 3300pF 20 ns
BG t
f
BG Fall Time C
LOAD
= 3300pF 20 ns
Internal V
CC
Regulator
V
INTVCC
Internal V
CC
Voltage 6V < V
IN1
<30V ● 4.7 5 5.3 V
∆V
LDO(LOAD)
Internal V
CC
Load Regulation I
CC
= 0mA to 20mA –0.1 ±2%
PGOOD Output
∆V
FB1H
PGOOD Upper Threshold V
FB1
= Rising 8 10 12 %
∆V
FB1L
PGOOD Lower Threshold V
FB1
= Falling –8 –10 –12 %
∆V
FB1(HYS)
PGOOD Hysterisis V
FB1
= Returning 1 2 %
V
PGL
PGOOD Low Voltage I
PGOOD
= 5mA 0.15 0.4 V
Boost Regulator
V
IN2(MIN)
Minimum Operating Voltage 0.9 1.5 V
V
IN2(MAX)
Maximum Operating Voltage 10 V
I
Q(VIN2)
Input DC Supply Current (V
IN2
)
Normal 3 4.5 mA
Shutdown Supply Current V
SHDN
=0V 0.01 1 µA
V
FB2
V
FB2
Feedback Voltage 0°C < T < 70°C 1.205 1.23 1.255 V
● 1.20 1.23 1.26 V
I
VFB2
V
FB2
Pin Bias Current ● 27 80 nA
∆V
FB2(LINE)
Boost Reference Line Regulation 1.5V < V
IN2
< 10V 0.02 0.2 %/V
f
BOOST
BOOST Switching Frequency 0°C < T < 70°C 1.0 1.4 1.8 MHz
● 0.9 1.4 1.9 MHz
DC
BOOST(MAX)
BOOST Maximum Duty Cycle 82 86 %
I
LIM(BOOST)
BOOST Switch Current Limit (Note 5) 500 800 mA
V
CESAT(BOOST)
BOOST Switch V
CESAT
I
SW
= 300mA 300 350 mV
I
SWLKG(BOOST)
BOOST Switch Leakage Current V
SW
= 5V 0.01 1 µA
V
SHDN(HIGH)
SHDN Input Voltage High 1 V
V
SHDN(LOW)
SHDN Input Voltage Low 0.3 V
I
SHDN
SHDN Pin Bias Current V
SHDN
= 3V 25 50 µA
V
SHDN
= 0V 0.01 0.1 µA