LTC3646-1_15 Datasheet, PDF (4/28 Pages) Linear Technology – 40V, 1A Synchronous Step-Down Converter

LTC3646/LTC3646-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.
SYMBOL
R_PGOOD
t_SS
V_MODE/SYNC
PARAMETER
PGOOD Pull-Down Resistance
PGOOD Leakage
Internal Soft-Start Time
Mode Threshold Voltage
SYNC Threshold Voltage
MODE/SYNC Input Current
Internal ITH Voltage Threshold
V_ON Pin Input Impedance
CONDITIONS
I_PGOOD = 10mA
V_PGOOD = V_INTVCC
Mode V_IH
Mode V_IL
SYNC_IH
SYNC_IL
LTC3646
LTC3646-1
MIN
TYP
63
250
l
1.2
l
l
1.2
l
1
l INTV_CC – 0.3V
520
600
MAX UNITS
Ω
1.0
µA
500
µs
V
0.3
V
V
0.3
V
2
µA
V
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.
36461fb
4
For more information www.linear.com/LTC3646