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LT3697
4
3697f
PARAMETER CONDITIONS MIN TYP MAX UNITS
Switching Frequency R
T
= 22.1k
R
T
= 63.4k
R
T
= 453k
l
l
l
1.8
0.9
250
2
1
300
2.25
1.12
350
MHz
MHz
KHZ
Foldback Frequency R
T
= 63.4k, V
SYS
= 0V 240 kHz
Minimum Switch On-Time I
SW
= 0.9A 100 160 ns
Minimum Switch Off-Time I
SW
= 0.9A 140 210 ns
Switch Current Limit (Note 8)
l
4.3 5.3 6.7 A
Switch V
CESAT
I
SW
= 2A 220 mV
SW Leakage Current V
EN
= 0.3V, V
BST
= 5V, V
SW
= 0V 0.1 1 µA
Minimum BST Voltage (Note 9) I
SW
= 2A 1.6 2.2 V
BST Current I
SW
= 2A 35 65 mA
EN Input Voltage High
l
2.5 V
EN Input Voltage Low
l
0.3 V
EN Current V
EN
= 2.5V 1 2 μA
SENSE Voltage to Trigger F LT Percentage of Nominal Sense Voltage 97 99.5 100 %
F LT Blanking 0.5 1.5 4 ms
F LT Leakage V
F LT
= 5V 0.1 1 μA
F LT Sink Current V
F LT
= 0.3V
l
100 180 μA
SYNC Threshold
l
0.4 0.7 1 V
SYNC Current V
SYNC
= 5V 0.1 μA
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: Absolute maximum voltage at V
IN
and EN is 60V for nonrepetitive
1 second transients, and 35V for continuous operation.
Note 3: The
LT3697E 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
LT3697I is guaranteed over the full –40°C to 125°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 4:
Note that the maximum ambient temperature consistent with
these specifications is determined by specific operating conditions in
conjunction with board layout, the rated package thermal impedance and
other environmental factors.
Note 5: This IC includes overtemperature protection that is intended
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
EN
= 12V unless otherwise noted. (Notes 3, 6)
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.
Note 6: Polarity specification for current into a pin is positive and out of
a pin is negative. All voltages are referenced to GND unless otherwise
specified. MAX and MIN refer to absolute
values.
Note 7:
SENSE Voltage is defined as the differential voltage applied across
the sense amplifier inputs, or V
ISP
– V
ISN
. SENSE voltage and V
SENSE
are
synonymous.
Note 8: Switch current limit is guaranteed by design and/or correlation to
static test. Slope compensation reduces switch current limit at higher duty
cycles.
Note 9: Boost voltage is the minimum voltage across the boost capacitor
needed to guarantee full saturation of the switch.
