LM2648 National Semiconductor, LM2648 Datasheet - Page 7

• Manufacturer Part Number: LM2648
• Description: Synchronous Step-Down 3-Channel Switching Regulator Controller
• Manufacturer: National Semiconductor

Electrical Characteristics
(Continued)
Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating Range indicates conditions for which the device is
intended to be functional, but does not guarantee specfic performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
The guaranteed specifications apply only for the test conditions. Some performance characteristics may degrade when the device is not operated under the listed
test conditions.
Note 2: The maximum allowable power dissipation is calculated by using P
= (T
- T
)/θ
, where T
is the maximum junction temperature, T
is the
DMAX
JMAX
A
JA
JMAX
A
ambient temperature and θ
is the junction-to-ambient thermal resistance of the specified package. The 1.3W rating results from using 125˚C, 25˚C, and 75˚C/W
JA
, and θ
respectively. A θ
for T
, T
of 75˚C/W represents the worst-case condition of no heat sinking of the 56-pin TSSOP. A thermal shutdown will occur if
JMAX
A
JA
JA
the temperature exceeds the maximum junction temperature of the device. θ
= 26˚C/W.
JC
Note 3: For detailed information on soldering plastic small-outline packages, refer to the Packaging Databook available from National Semiconductor Corporation.
Note 4: For testing purposes, ESD was applied using the human-body model, a 100pF capacitor discharged through a 1.5kΩ resistor.
Note 5: A typical is the center of characterization data measured with low duty cycle pulse tsting at T
= 25˚C. Typicals are not guaranteed.
A
Note 6: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production with T
= T
= 25˚C. All hot and cold limits
A
J
are guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Note 7: All switching controllers are off. The linear regulator VLIN5 remains on.
7
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