LT3580
3
3580fg
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. The LT3580H is guaranteed over the full –40°C to
ELECTRICAL CHARACTERISTICS
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)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Operating Voltage Range
l
2.5 32 V
Positive Feedback Voltage
l
1.195 1.215 1.230 V
Negative Feedback Voltage
l
0 5 12 mV
Positive FB Pin Bias Current V
FB
= Positive Feedback Voltage, Current Into Pin
l
81 83.3 85 μA
Negative FB Pin Bias Current V
FB
= Negative Feedback Voltage, Current Out of Pin
(LT3580E, LT3580I, LT3580MP)
(LT3580H)
l
l
81
81
83.3
83.3
85.5
86
μA
μA
Error Amplifier Transconductance
230 μmhos
Error Amplifier Voltage Gain 70 V/V
Quiescent Current V
SHDN
= 2.5V, Not Switching 1 1.5 mA
Quiescent Current in Shutdown V
SHDN
= 0V 0 1 μA
Reference Line Regulation 2.5V ≤ V
IN
≤ 32V 0.01 0.05 %/V
Switching Frequency, f
OSC
R
T
= 45.3k (LT3580E, LT3580I, LT3580H)
R
T
= 45.3k (LT3580MP)
R
T
= 464k (LT3580E, LT3580I, LT3580H)
R
T
= 464k (LT3580MP)
l
l
l
l
1.8
1.8
180
180
2
2
200
200
2.2
2.25
220
225
MHz
MHz
kHz
kHz
Switching Frequency in Foldback Compared to Normal f
OSC
1/4 Ratio
Switching Frequency Set Range SYNCing or Free Running
l
200 2500 kHz
SYNC High Level for Synchronization
l
1.3 V
SYNC Low Level for Synchronization
l
0.4 V
SYNC Clock Pulse Duty Cycle V
SYNC
= 0V to 2V 35 65 %
Recommended Minimum SYNC Ratio f
SYNC
/f
OSC
3/4
Minimum Off-Time 60 ns
Minimum On-Time 100 ns
Switch Current Limit Minimum Duty Cycle (Note3) (LT3580E, LT3580I, LT3580H)
Minimum Duty Cycle (Note3) (LT3580MP)
Maximum Duty Cycle (Notes 3, 4) (LT3580E, LT3580I,
LT3580MP)
Maximum Duty Cycle (Notes 3, 4) (LT3580H)
l
l
l
l
2.2
2.15
1.6
1.55
2.5
2.2
1.9
1.9
2.8
2.8
2.6
2.6
A
A
A
A
Switch V
CESAT
I
SW
= 1.5A 300 mV
Switch Leakage Current V
SW
= 5V 0.01 1 μA
Soft-Start Charging Current V
SS
= 0.5V
l
468 μA
SHDN Minimum Input
Voltage High
Active Mode, SHDN Rising (LT3580E, LT3580I)
Active Mode, SHDN Rising (LT3580H, LT3580MP)
Active Mode, SHDN Falling (LT3580E, LT3580I)
Active Mode, SHDN Falling (LT3580H, LT3580MP)
l
l
l
l
1.27
1.25
1.24
1.22
1.32
1.32
1.29
1.29
1.38
1.4
1.33
1.35
V
V
V
V
SHDN Input Voltage Low Shutdown Mode
l
0.3 V
SHDN Pin Bias Current V
SHDN
= 3V
V
SHDN
= 1.3V
V
SHDN
= 0V
9.7
40
11.6
0
60
13.4
0.1
μA
μA
μA
150°C operating junction temperature range. The LT3580MP is guaranteed
over the full –55°C to 125°C operating junction temperature range.
Operating lifetime is derated at junction temperatures greater than 125°C.
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 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
