Datasheet

LTC3646/LTC3646-1
4
36461fa
For more information www.linear.com/LTC3646
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
R
PGOOD
PGOOD Pull-Down Resistance I
PGOOD
= 10mA 63 Ω
PGOOD Leakage V
PGOOD
= V
INTVCC
1.0 µA
t
SS
Internal Soft-Start Time 250 500 µs
V
MODE/SYNC
Mode Threshold Voltage
SYNC Threshold Voltage
Mode V
IH
Mode V
IL
SYNC
IH
SYNC
IL
l
l
l
l
1.2
1.2
0.3
0.3
V
V
V
V
MODE/SYNC Input Current 1
2 µA
Internal ITH Voltage Threshold
l
INTV
CC
– 0.3V V
V
ON
Pin Input Impedance LTC3646
LTC3646-1
520
600
kΩ
kΩ
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 LTC3646 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3646E is guaranteed to meet specifications from
0°C to 85°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
LTC3646I is guaranteed over the –40°C to 125°C operating junction
temperature range and the LTC3646H is guaranteed over the –40°C to
150°C operating junction temperature range. High junction temperatures
derate operating lifetimes; operating lifetime is derated for
junction
temperatures greater than 125°C. 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:
Dynamic supply current is higher due to gate charging being
delivered at the switch frequency.
Note 4: Limits to V
OUT
are a subject to PVIN, SVIN, t
ON(MIN)
, t
OFF(MIN)
,
and frequency constraints. See the Applications Information section for a
further discussion. These items are tested with appropriate combinations
of V
IN
, V
ON
and frequency.
Note 5: R
DS(ON)
is guaranteed by correlation to wafer level measurements.
Note 6: Maximum allowed current draw when used as a regulated output
is 5mA. This supply is only intended to provide additional DC load current
as needed and not to regulate large transient or AC behavior as such
waveforms may impact LTC3646 operation.
Note 7: This IC includes overtemperature protection intended to protect
the device during momentary overload conditions. The maximum junction
temperature may be exceeded when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may result in device degradation or failure.