Datasheet

LT3517
3
3517fg
For more information www.linear.com/LT3517
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum V
IN
Operating Voltage 3 V
Maximum V
IN
Operating Voltage Continuous Operation (Note 3) 30 V
Current Sense Voltage (V
ISP
– V
ISN
) V
CTRL
= 2V, V
ISP
= 24V, VC = 1V
V
CTRL
= 2V, V
ISP
= 0V, VC = 1V
●
96 100
100
103 mV
mV
10% Scale Current Sense Voltage (V
ISP
– V
ISN
) V
CTRL
= 100mV, V
ISP
= 24V, VC = 1V 9 mV
Current Sense Voltage Line Regulation 2V < V
ISP
< 45V 0.03 %/V
V
IN
Supply Current PWM > 1.5V, VC = 0V
PWM = 0V
SHDN = 0V
6
4.5
0.1
10
1
mA
mA
µA
Switching Frequency R
T
= 16.7k
R
T
= 4.03k
R
T
= 91.5k
●
0.85
2.25
220
1
2.5
250
1.15
2.7
270
MHz
MHz
kHz
RT Voltage 1 V
Soft-Start Pin Current SS = 0.5V, Out of Pin 6 9 12 µA
SYNC Pull-Down Current (Into the Pin) V
SYNC
= 2V 60 µA
SYNC Input Low 0.4 V
SYNC Input High 1.5 V
Maximum Duty Cycle R
T
= 91.5k (250kHz)
SYNC = 300kHz Clock Signal, R
T
= 91.5k
R
T
= 16.7k (1MHz)
R
T
= 4.03k (2.5MHz)
●
95
94
85
97
96
90
74
%
%
%
%
Switch Current Limit 1.5 1.9 2.3 A
Switch V
CESAT
I
SW
= 1A 300 mV
Switch Leakage Current V
SW
= 45V, PWM = 0V 2 µA
CTRL Input Bias Current Current Out of Pin, V
CTRL
= 0.1V 20 100 nA
Error Amplifier Transconductance 550 µS
VC Output Impedance 1000 kΩ
VC Idle Input Bias Current PWM = 0V, VC = 1V –20 0 20 nA
FB Pin Input Bias Current Current Out of Pin, V
FB
= 0.5V 20 100 nA
FB Pin Threshold
●
0.98 1.01 1.04 V
ISP
, ISN Idle Input Bias Current PWM = 0V, ISP = ISN = 24V 300 nA
ISP
, ISN Full-Scale Input Bias Current ISP Tied to ISN, V
ISP
= 24V, V
CTRL
= 2V 20 µA
SHDN Voltage High
●
1.2 V
SHDN Voltage Low –40°C ≤ T
J
≤ 125°C
125°C < T
J
≤ 150°C
0.45
0.40
V
V
SHDN Pin Bias Current 60 100 µA
PWM Input High Voltage
●
1.2 V
PWM Input Low Voltage –40°C ≤ T
J
≤ 125°C
125°C < T
J
≤ 150°C
0.45
0.40
V
V
PWM Pin Bias Current 60 120 µA
The ● 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.