Datasheet

LT3592
3
3592fc
ELECTRICAL CHARACTERISTICS
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 LT3592E is guaranteed to meet performance specifi cations
from 0°C to 125°C junction temperature. Specifi cations over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3592I is guaranteed over the full –40°C to 125°C operating junction
temperature range. The operating lifetime is derated at junction
temperatures greater than 125°C.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage
l
3.25 3.6 V
Input Quiescent Current in Shutdown Not Switching
V
SHDN
= 0.3V
2
0.1
3
2
mA
µA
CAP to OUT Voltage 0.4 CAP to OUT
BRIGHT = 1.4V
BRIGHT = 0.3V
l
l
190
18
200
20
210
22
mV
mV
DA Pin Current to Stop OSC –0.8 –1 –1.2 A
Switching Frequency R
T
= 357k
R
T
= 140k
R
T
= 48.7k
350
800
1.9
400
900
2.2
450
1000
2.5
kHz
kHz
MHz
Maximum Duty Cycle R
T
= 140k 90 94 %
SHDN Input High Voltage 2.3 V
SHDN Input Low Voltage 0.3 V
BRIGHT Input High Voltage 1.4 V
BRIGHT Input Low Voltage 0.3 V
Switch Current Limit (Note 4)
l
0.85 1.25 1.5 A
Switch V
CESAT
I
SW
= 500mA 300 mV
Boost Pin Current I
SW
= 500mA 20 30 mA
Switch Leakage Current 110 µA
Minimum Boost Voltage (V
BOOST
– V
IN
)V
OUT
= 4V 1.8 2.5 V
Boost Diode Forward Voltage I
DIO
= 50mA 800 mV
V
FB
Voltage OUT = CAP = 4V, Bright = 12V
l
1.185 1.21 1.235 V
V
FB
Input Leakage Current V
FB
= 1.21V
l
–250 250 nA
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 12V, V
BOOST
= 16V, V
OUT
= 4V unless otherwise noted. (Note 2)
Note 3: 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 specifi ed maximum operating junction temperature may result in
device degradation or failure.
Note 4: Switch Current Measurements are performed when the outputs
are not switching. Slope compensation reduces current limit at higher duty
cycles.