Datasheet
LT3500
3
3500fc
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
J
= 25°C. V
VIN
= 15V, V
RT/SYNC
= 2V, unless otherwise specifi ed.
PARAMETER CONDITIONS MIN TYP MAX UNITS
SHDN Threshold
l
710 760 780 mV
SHDN Source Current V
SHDN
= 0.62V 1.5 2.5 3.5 µA
SHDN Current Hysterisis 1.25 2 3.25 µA
Minimum Input Voltage (Note 3) V
FB
= 0V
l
2.4 2.8 V
Supply Shutdown Current V
SHDN
= 0V
l
12 30 µA
Supply Quiescent Current V
FB
= 0.9V 2.5 3.5 mA
FB Voltage V
VC
= 1V
V
VC
= 0.8V to 1.6V, V
IN
= 3V to 40V
l
l
0.784
0.776
0.8
0.8
0.816
0.824
V
V
FB Bias Current V
FB
= 0.8V, V
VC
= 1V 50 150 nA
Error Amplifi er g
m
V
VC
= 1V, I
VC
= ±10µA 150 250 350 µmho
Error Amplifi er Source Current V
FB
= 0.6V, V
VC
= 1V 12 16 20 µA
Error Amplifi er Sink Current V
FB
= 1V, V
VC
= 1V 14 18 22 µA
Error Amplifi er High Clamp V
FB
= 0.6V 1.8 2.0 2.2 V
Error Amplifi er Switching Threshold V
FB
= 0.6V 0.6 0.8 1.0 V
SS Source Current V
SS
= 0.4V, V
FB
= 0.9V 2.25 2.75 3.75 µA
SS Sink Current V
FB
= 0V, V
SS
= 2V 300 600 900 µA
SS POR Sink Current (Note 4) V
FB
= 0V, V
SS
= 2V, Cycle SHDN 400 600 800 µA
SS POR Threshold 50 100 150 mV
SS to FB Offset (V
SS
– V
FB
)V
VC
= V
FS
, V
SS
= 0.4V 70 100 120 mV
PG/PG Leakage V
FB
= 0.9V, V
PG
/V
PG
= 40V 0.1 1 µA
PG/PG Threshold (Rising) V
PG
= 0.4V 0.685 0.708 0.730 V
PG/PG Hysteresis (Falling) V
PG
= 0.4V 20 30 40 mV
PG Sink Current V
PG
= 0.4V, V
FB
= 0.7V 250 500 750 µA
PG Sink Current V
PG
= 0.4V, V
FB
= 0.9V 500 800 1100 µA
R
T
/SYNC Reference Voltage V
FB
= 0.9V, R
RT/SYNC
= 15k 0.75 0.850 0.975 V
Switching Frequency R
RT/SYNC
= 90.9k
R
RT/SYNC
= 90.9k
R
RT/SYNC
= 15k
l
450
425
2
500
500
2.4
550
625
2.8
kHz
kHz
MHz
SYNC Frequency Range
l
250 2500 kHz
Minimum Switch On Time V
FB
= 0.7V, R
RT/SYNC
= 90.9k 140 ns
Minimum Switch Off Time V
FB
= 0.7V, R
RT/SYNC
= 90.9k 120 ns
Switch Leakage Current V
SW
= 0V 1 10 µA
Switch Saturation Voltage I
SW
= 2A, V
BST
= 18V, V
FB
= 0.7V 450 mV
Switch Peak Current DD Package V
BST
= 18V, V
FB
= 0.7V
l
2.3
2.1
2.8
2.8
3.5
3.5
A
A
Switch Peak Current MSE Package V
BST
= 18V, V
FB
= 0.7V
l
2.3
2.1
2.9
2.9
3.5
3.7
A
A
Boost Current I
SW
= 2A, V
BST
= 20V, V
FB
= 0.7V 20 30 45 mA
Minimum Boost Voltage (Note 5) I
SW
= 2A, V
FB
= 0.7V 2.2 3 V
ELECTRICAL CHARACTERISTICS