LT3580
ELECTRICAL CHARACTERISTICS
PARAMETER
Operating Voltage Range
Positive Feedback Voltage
Negative Feedback Voltage
Positive FB Pin Bias Current
Negative FB Pin Bias Current
Error Amplifier Transconductance
Error Amplifier Voltage Gain
Quiescent Current
Quiescent Current in Shutdown
Reference Line Regulation
Switching Frequency, f
OSC
Switching Frequency in Foldback
Switching Frequency Set Range
SYNC High Level for Synchronization
SYNC Low Level for Synchronization
SYNC Clock Pulse Duty Cycle
Recommended Minimum SYNC Ratio f
SYNC
/f
OSC
Minimum Off-Time
Minimum On-Time
Switch Current Limit
Switch V
CESAT
Switch Leakage Current
Soft-Start Charging Current
SHDN
Minimum Input
Voltage High
SHDN
Input Voltage Low
SHDN
Pin Bias Current
Minimum Duty Cycle (Note 3)
Maximum Duty Cycle (Notes 3, 4)
I
SW
= 1.5A
V
SW
= 5V
V
SS
= 0.5V
Active Mode,
SHDN
Rising
Active Mode,
SHDN
Falling
Shutdown Mode
V
SHDN
= 3V
V
SHDN
= 1.3V
V
SHDN
= 0V
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V, V
SHDN
= V
IN
unless otherwise noted. (Note 2)
CONDITIONS
l
l
l
l
l
MIN
2.5
1.195
0
81
81
TYP
1.215
5
83.3
83.3
230
70
MAX
32
1.230
12
85
85.5
UNITS
V
V
mV
μA
μA
μmhos
V/V
V
FB
= Positive Feedback Voltage, Current Into Pin
V
FB
= Negative Feedback Voltage, Current Out of Pin
V
SHDN
= 2.5V, Not Switching
V
SHDN
= 0V
2.5V ≤ V
IN
≤ 32V
R
T
= 45.3k
R
T
= 464k
Compared to Normal f
OSC
SYNCing or Free Running
l
l
l
l
l
1
0
0.01
1.8
180
200
1.3
2
200
1/4
1.5
1
0.05
2.2
220
2500
0.4
mA
μA
%/V
MHz
kHz
Ratio
kHz
V
V
%
nS
nS
V
SYNC
= 0V to 2V
35
3/4
60
100
2.2
1.6
2.5
1.9
300
0.01
4
1.27
1.24
6
1.32
1.29
40
11.6
0
65
2.8
2.6
1
8
1.38
1.33
0.3
60
13.4
0.1
A
A
mV
μA
μA
V
V
V
μA
μA
μA
9.7
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 LT3580E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3580I is guaranteed over the full –40°C to 125°C operating junction
temperature range.
Note 3:
Current limit guaranteed by design and/or correlation to static test.
Note 4:
Current limit measured at equivalent switching frequency of
2.5MHz.
Note 5:
This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is
active. Continuous operation above the specified maximum operating
junction temperature may impair device reliability.
3580fc
3
LINER [ LINEAR TECHNOLOGY ]
