LP38859-1.2EVAL National Semiconductor, LP38859-1.2EVAL Datasheet - Page 2

• Manufacturer Part Number: LP38859-1.2EVAL
• Description: BOARD EVALUATION LP38859-1.2
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LP38859-1.2EVAL

• Channels Per Ic: 1 - Single
• Voltage - Output: 1.2V
• Current - Output: 3A
• Voltage - Input: 3 ~ 5.5V
• Regulator Type: Positive Fixed
• Operating Temperature: -40°C ~ 125°C
• Board Type: Fully Populated
• Utilized Ic / Part: LP38859
• Lead Free Status / RoHS Status: Not applicable / Not applicable

PCB Layout
20193602
Evaluation Board Component and Pin Layout
Power Dissipation
The TO-263 package alone has a junction to ambient ther-
mal resistance (θ
) rating of 60˚C/W. When mounted on the
JA
LP38859S evaluation board the θ
rating is approximately
JA
37˚C/W.
Although there is only approximately 0.28 square inches of
copper area immediately under the tab, the top copper sur-
face area is extended to additional copper area on the
bottom of the board by five thermal vias.
With the 37˚C/W thermal rating the LP38859S evaluation
board will dissipate a maximum of 2.75W with T
= 25˚C.
A
20193606
FIGURE 2. Maximum Power Dissipation vs Ambient
Temperature
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