LT3518
ELECTRICAL CHARACTERISTICS
PARAMETER
Minimum V
IN
Operating Voltage
Maximum V
IN
Operating Voltage
Current Sense Voltage (V
ISP
– V
ISN
)
10% Scale Current Sense Voltage (V
ISP
– V
ISN
)
Current Sense Voltage Line Regulation
V
IN
Supply Current
Continuous Operation (Note 3)
V
CTRL
= 2V, V
ISP
= 24V, V
C
= 1V
V
CTRL
= 2V, V
ISP
= 0V, V
C
= 1V
V
CTRL
= 100mV, V
ISP
= 24V, V
C
= 1V
2V < V
ISP
< 45V
PWM > 1.5V, V
C
= 0V
PWM = 0V
SHDN
= 0V
R
T
= 16.7k
R
T
= 4.03k
R
T
= 91.5k
SS = 0.5V, Out of Pin
V
SYNC
= 2V
1.5
R
T
= 91.5k (250kHz)
SYNC = 300kHz Clock Signal, R
T
= 91.5k
R
T
= 16.7k (1MHz)
R
T
= 4.03k (2.5MHz)
I
SW
= 1.5A
V
SW
= 45V, PWM = 0V
Current Out of Pin, V
CTRL
= 0.1V
20
550
1000
PWM = 0, V
C
= 1V
Current Out of Pin, V
FB
= 0.5V
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 2) V
IN
= 5V,
SHDN
= 5V, PWM = 5V unless otherwise noted.
CONDITIONS
MIN
30
96
100
100
9
0.03
6
4.5
0.1
0.85
2.25
220
6
1.0
2.5
250
1
9
60
0.4
95
94
85
2.3
97
96
90
74
2.8
400
2
100
3.5
12
10
1
1.15
2.7
270
103
TYP
MAX
3
UNITS
V
V
mV
mV
mV
%/V
mA
mA
μA
MHz
MHz
kHz
V
μA
μA
V
V
%
%
%
%
A
mV
μA
nA
μS
kΩ
20
100
1.04
300
20
1.5
0.4
60
1.5
0.4
60
1.5
0.4
TGEN = 5V
I
REF
= –100μA
l
Switching Frequency
R
T
Voltage
Soft-Start Pin Current
SYNC Pull-Down Current (Into the Pin)
SYNC Input Low
SYNC Input High
Maximum Duty Cycle
l
Switch Current Limit
Switch V
CESAT
Switch Leakage Current
CTRL Input Bias Current
Error Amplifier Transconductance
V
C
Output Impedance
V
C
Idle Input Bias Current
FB Pin Input Bias Current
FB Pin Threshold
ISP , ISN Idle Input Bias Current
ISP , ISN Full-Scale Input Bias Current
SHDN
Voltage High
SHDN
Voltage Low
SHDN
Pin Bias Current
PWM Input High Voltage
PWM Input Low Voltage
PWM Pin Bias Current
TGEN Input High Voltage
TGEN Input Low Voltage
TGEN Pin Bias Current
V
REF
Pin Voltage
PWM = 0V
ISP Tied to ISN, V
ISP
= 24V, V
CTRL
= 2V
–20
0.98
0
20
1.01
nA
nA
V
nA
μA
V
V
μA
V
V
μA
V
V
μA
V
3518fb
100
120
100
1.96
2
200
2.04
3
LINER [ LINEAR TECHNOLOGY ]
