Datasheet

LT3512
3
3512fb
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
= 24V unless otherwise noted.
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 LT3512E 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
LT3512I is guaranteed to meet performance specifications from –40°C to
125°C operating junction temperature range. The LT3512H is guaranteed
PARAMETER CONDITIONS MIN TYP MAX UNITS
T
C
Current into R
REF
R
TC
= 53.6k 9.5 μA
BIAS Pin Voltage Internally Regulated 3 3.1 3.2 V
to meet performance specifications from –40°C to 150°C operating
junction temperature range. The LT3511MP is guaranteed over the full
–55°C to 150°C operating junction range. High junction temperatures
degrade operating lifetimes. Operating lifetime is derated at junction
temperatures greater than 125°C.
Note 3: Current flows out of the R
REF
pin.
Note 4: The SW pin is rated to 150V for transients. Operating waveforms
of the SW pin should keep the pedestal of the flyback waveform below
100V as shown in Figure 5.
Typical perForMance characTerisTics
Switch V
CESAT
Switch Current Limit Quiescent Current vs V
IN
Output Voltage Quiescent Current BIAS Pin Voltage
T
A
= 25°C, unless otherwise noted.
TEMPERATURE (°C)
–50 –25
0
I
Q
(mA)
4
8
0
50
75
3512 G02
2
6
25
100
150125
V
IN
= 24V
V
IN
= 48V
V
IN
= 100V
TEMPERATURE (°C)
–50
2.0
BIAS VOLTAGE (V)
2.5
3.0
3.5
4.0
–25 0 25 50
3512 G03
75 100 150125
V
IN
= 24V, 10mA
V
IN
= 24V, NO LOAD
SWITCH CURRENT (mA)
0
0
SWITCH V
CESAT
VOLTAGE (mV)
800
2000
100 200
300
3512 G04
400
1600
1200
400
500
TEMPERATURE (°C)
–50
CURRENT LIMIT (mA)
700
25
3512 G05
400
200
–25 0 50
100
0
800
600
500
300
75 100 150125
MINIMUM CURRENT LIMIT
MAXIMUM CURRENT LIMIT
VOLTAGE (V)
0
I
Q
(mA)
2
4
3
80
3512 G06
1
0
20
40
60
100
5
TEMPERATURE (°C)
–50
4.75
V
OUT
(V)
4.80
4.90
4.95
5.00
5.25
5.10
0
50
75
3512 G01
4.85
5.15
5.20
5.05
–25 25
100
125
150
V
IN
= 48V