Datasheet

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6 Enable Function
ON/OFF control is provided by supplying a logic level signal to the Enable pin. A minimum V
EN
value of
1.2V is typically required at this pin to enable the LDO output. The LDO output will be shutdown when the
V
EN
value is typically 0.6V or less. The V
EN
threshold incorporates approximately 100 mV of hysteresis.
In applications where the LP38512MR-ADJ is operated continuously the Enable pin can be connected
directly to V
IN
. The Enable pin has no default bias and must not be left floating. The Enable pin must be
actively driven to the appropriate voltage level.
Figure 3. V
OUT
vs V
EN
Figure 4. Enable Thresholds
7 Power Dissipation
The PSOP-8 package alone has a junction to ambient thermal resistance (θ
JA
) rating of 168°C/W when
mounted to the minimum land area (EIA/JESD51-3). When mounted on the LP38512MR-ADJ Evaluation
Board the θ
JA
rating is approximately 40°C/W.
The exposed DAP is soldered to the copper area immediately under the package. The top copper surface
area is extended to additional copper area on the bottom of the board by five thermal vias placed inside
the DAP land area.
With the 40°C/W thermal rating the LP38512MR-ADJ evaluation board will dissipate a maximum of 2.5W
with T
A
= 25°C.
Figure 5. Maximum Power Dissipation vs Ambient Temperature
3
SNVA351B–March 2009–Revised April 2013 AN-1859 LP38512MR-ADJ Evaluation Board
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