Data Sheet

LT3652
4
3652fe
For more information www.linear.com/LT3652
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
TIMER
Full Charge Cycle Timeout 3 hr
Precondition Timeout 22.5 min
Timer Accuracy
l
–10 10 %
f
O
Operating Frequency 1 MHz
DC Duty Cycle Range Continuous Operation
l
15 90 %
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 20V, Boost – SW = 4V, SHDN = 2V, V
FB
= 3.3V, C
TIMER
= 0.68µF.
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 LT3652EDD 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
LT3652IDD specifications are guaranteed over the full –40°C to 125°C
operating junction temperature range. 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 3: V
IN
minimum voltages below the start threshold are only
supported if (V
BOOST
-V
SW
) > 2V.
Note 4: This parameter is valid for programmed output battery float
voltages ≤ 4.2V. V
IN
operating range minimum is 0.75V above the
programmed output battery float voltage (V
BAT(FLT)
+ 0.75V). V
IN
Start
Voltage is 3.3V above the programmed output battery float voltage
(V
BAT(FLT)
+ 3.3V).
Note 5: Output battery float voltage (V
BAT(FLT)
) programming resistor
divider equivalent resistance = 250k compensates for input bias current.
Note 6: All V
FB
voltages measured through 250k series resistance.
Note 7: V
SENSE(DC)
is reduced by thermal foldback as junction temperature
approaches 125°C.
ELECTRICAL CHARACTERISTICS