LTC3805
4
3805fg
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 LTC3805 is tested under pulsed conditions such that T
J
≈ T
A
.
The LTC3805E is guaranteed to meet specifications from 0°C to 85°C.
Specifications over the –40°C to 85°C operating junction temperature
range are assured by design, characterization and correlation with
statistical process controls. The LTC3805I is guaranteed over the –40°C to
125°C operating junction temperature range, the LTC3805H is guaranteed
over the full –40°C to 150°C operating junction temperature range, and
the LTC3805MP is tested and guaranteed over the full –55°C to 150°C
operating temperature range. High junction temperatures degrade
operating lifetimes. Operating lifetime is derated at junction temperatures
greater than 125°C. Note that the maximum ambient temperature
consistant with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
T
J
= T
A
+ (P
D
• 45°C/W)
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: The LTC3805 is tested in a feedback loop that servos V
FB
to the
output of the error amplifier while maintaining I
TH
at the midpoint of the
current limit range.
Note 6: Peak current sense voltage is reduced dependent on duty cycle
and an optional external resistor in series with the SENSE pin. For
details, refer to Programmable Slope Compensation in the Applications
Information section.
Note 7: Guaranteed by design.
Note 8: Overcurrent threshold voltage is reduced dependent on an
optional external resistor in series with the OC pin. For details, refer to
Programmable Overcurrent in the Applications Information section.
