Datasheet

LT3686A
3
3686afa
PARAMETER CONDITIONS MIN TYP MAX UNITS
Quiescent Current at Shutdown V
EN/UVLO
< 0.4V
V
EN/UVLO
= 1V
0.1
10
1
15
µA
µA
Quiescent Current Not Switching, SYNC/MODE ≤ 0.4V
Not Switching, SYNC/MODE ≥ 0.8V
1.1
1.2
1.3
1.4
mA
mA
Internal Undervoltage Lockout 3.4 3.6 V
Overvoltage Lockout
●
37 38 39 V
Feedback Voltage V
IN
= 3.6V ↔ 37V
●
0.790
0.785
0.8
0.8
0.810
0.815
V
V
FB Pin Bias Current 60 100 nA
Switching Frequency I
DA
< 1.2A
R
T
= 15.4kΩ, IDA < 1.2A
0.3
1.9 2.1
2.5
2.3
MHz
MHz
Minimum On Time SYNC/MODE > 0.8V, BD < 6V 100 110 ns
Minimum Off Time 150 200 ns
Switch V
CESAT
I
SW
= 1.2A 680 mV
Switch Current Limit (Note 3)
●
1.9
1.85
2.3
2.3
2.6
2.65
A
A
Switch Active Current SW = 10V (Note 4)
SW = 0V (Note 5)
400
20
600
30
µA
µA
BOOST Pin Current I
SW
= 1.2A 20 mA
Minimum Boost Voltage Above Switch I
SW
= 1.2A 2.2 2.4 V
Max BD Pin Active Load Current SYNC/MODE > 0.8V, BD < 6V 30 40 mA
BD Pin Voltage to Disable Active Load
●
6 6.5 7 V
DA Pin Current to Stop OSC
●
1.2 1.7 A
SYNC/MODE High
●
0.8 V
SYNC/MODE Low
●
0.4 V
SYNC/MODE Bias Current 0.2 µA
SS Threshold 0.9 V
SS Source Current V
SS
= 1V 1.3 2 2.7 µA
EN/UVLO Bias Current V
EN/UVLO
= 10V
V
EN/UVLO
= 0V
40
1
µA
µA
EN/UVLO Threshold to Turn Off
●
1.22 1.28 1.34 V
EN/UVLO Hysteresis Current 1.8 2.4 3 µA
Boost Diode Forward Drop I
BD
to I
BOOST
= 200mA 0.85 V
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 10V, V
EN/UVLO
≥ 1.34V.
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 LT3686AE 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
LT3686AI is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT3686AH is guaranteed over the full –40°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes; operating lifetime is derated for junction
temperatures greater than 125°C. (Note 6)
Note 3: Current limit guaranteed by design and/or correlation to static test.
Slope compensation reduces current limit at higher duty cycle.
Note 4: Current flows into pin.
Note 5: Current flows out of pin.
Note 6: 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 specified maximum
operating junction temperature may impair device reliability. See High
Temperature Considerations section. Also see Operation section.
Note 7: Absolute Maximum Voltage at V
IN
and EN/UVLO pins is 60V for
nonrepetitive one second transients, and 55V for continuous operation.