LTC3899_15 Datasheet, PDF (6/38 Pages) Linear Technology – 60V Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

LTC3899
Electrical Characteristics
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Ratings for extended periods may affect device reliability and
lifetime.
Note 2: The LTC3899 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3899E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3899I is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC3899H is guaranteed over the –40°C to 150°C operating junction
temperature range, and the LTC3899MP is tested and guaranteed over
the –55°C to 150°C operating junction temperature range. High junction
temperatures degrade operating lifetimes; operating lifetime is derated
for junction temperatures greater than125°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. The junction
temperature (T_J, in °C) is calculated from the ambient temperature
(T_A, in °C) and power dissipation (P_D, in Watts) according to the formula:
T_J = T_A + (P_D • θ_JA)
where θ_JA = 34°C/W for the QFN package and where θ_JA = 25°C/W for the
TSSOP package.
Note 3: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. The maximum
rated junction temperature will be exceeded when this protection is active.
Continuous operation above the specified absolute maximum operating
junction temperature may impair device reliability or permanently damage
the device.
Note 4: The LTC3899 is tested in a feedback loop that servos V_ITH1,2,3 to a
specified voltage and measures the resultant V_FB1,2,3. The specification at
85°C is not tested in production and is assured by design, characterization
and correlation to production testing at other temperatures (125°C for
the LTC3899E and LTC3899I, 150°C for the LTC3899H and LTC3899MP).
For the LTC3899I and LTC3899H, the specification at 0°C is not tested in
production and is assured by design, characterization and correlation to
production testing at –40°C. For the LTC3899MP, the specification at 0°C
is not tested in production and is assured by design, characterization and
correlation to production testing at –55°C.
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications information.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels
Note 7: The minimum on-time condition is specified for an inductor
peak-to-peak ripple current >40% of I_MAX (See Minimum On-Time
Considerations in the Applications Information section).
Note 8: Do not apply a voltage or current source to these pins. They must be
connected to capacitive loads only, otherwise permanent damage may occur.
3899f
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For more information www.linear.com/LTC3899