Datasheet

LT3517
4
3517fg
For more information www.linear.com/LT3517
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.
TYPICAL PERFORMANCE CHARACTERISTICS
V
ISP
– V
ISN
Threshold vs V
CTRL
Switch Current Limit
vs Duty Cycle
Oscillator Frequency vs R
T
V
CTRL
(V)
0
0
V
ISP
– V
ISN
THRESHOLD (mV)
20
40
60
80
0.4 0.8
1.2
1.6
3518 G01
100
120
0.2 0.6
1.0
1.4
V
IN
= 5V
V
ISP
= 24V
VC = 1V
T
A
= 25°C
R
T
(kΩ)
1
100
OSCILLATOR FREQUENCY (kHz)
1000
10000
10 100
3518 G03
T
A
= 25°C
DUTY CYCLE (%)
0
0
SWITCH CURRENT LIMIT (A)
0.5
1.0
1.5
2.0
20 40 60 80
3517 G02
100
T
A
= 25°C
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT3517E is guaranteed to meet performance specifications
from 0°C to 125°C operating junction temperature range. Specifications
over the –40°C to 125°C operating junction temperature range are
assured by design, characterization and correlation with statistical
process controls. The LT3517I is guaranteed over the full –40°C to 125°C
operating junction temperature range. The LT3517H is guaranteed over
the full –40°C to 150°C operating junction temperature range. Operating
lifetime is derated at junction temperatures greater than 125°C.
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
TGEN Input High Voltage 1.5 V
TGEN Input Low Voltage 0.4 V
TGEN Pin Bias Current TGEN = 5V 100 200 µA
V
REF
Pin Voltage I
REF
= –100µA
●
1.96 2 2.04 V
V
REF
Pin Voltage Line Regulation 3V < V
IN
< 40V 0.03 %/V
Gate Turn-On Delay C
LOAD
= 1nF Between ISP and TG 200 ns
Gate Turn-Off Delay C
LOAD
= 1nF Between ISP and TG 200 ns
Top Gate Drive V
GS
(V
ISP
– V
TG
) V
ISP
= 24V, TGEN = 5V
PWM = 0V
7
0 0.3
V
V
Note 3: Absolute maximum voltage at V
IN
, SHDN, PWM and TGEN pins
is 40V for nonrepetitive 1 second transients and 30V for continuous
operation.
Note 4: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum operating junction temperature
when overtemperature protection is active. Continuous operation above
the specified maximum operating junction temperature may impair device
reliability.