GENERAL
CONSIDERATIONS
PA60
THERMAL CONSIDERATIONS
The PA60EU has a large exposed copper heat tab to which
the monolithic is directly attached. The PA60EU may require
a thermal washer, which is electrically insulating since the tab
is directly tied to -VS. This can result in a thermal impedance
RCS of up to 1˚C/W or greater.
The PA60DK has a large exposed integrated copper heatslug
to which the monolithic is directly attached. The solder connec-
tion of the heatslug to a minimum of 1 square inch foil area of
the printed circuit board will result in thermal performance of
25°C/W junction to air rating of the PA60DK. Solder connec-
tion to an area of 1 to 2 square inches of foil is required for
minimal power applications
Where the PA60DK is used in higher power applications,
it is necessary to use surface mount techniques of heatsink-
ing. Surface mount techniques include the use of a surface
mount fan in combination with a surface mount heatsink on
the backside of the FR4/ PC board with through hole thermal
vias. Other highly thermal conductive substrate board materials
are available for maximum heat sinking.
GENERAL
Please read Application Note 1 "General Operating Consider-
ations" which covers stability, supplies, heatsinking, mounting,
SOA interpretation, and specification interpretation. Visit www.
apexmicrotech.com for design tools that help automate tasks
such as calculations for stability, internal power dissipation,
heatsink selection; Apex's complete Application Notes library;
Technical Seminar Workbook; and Evaluation Kits.
STABILITY CONSIDERATIONS
All monolithic power op amps use output stage topologies
that present special stability problems. This is primarily due to
non-complementary (both devices are NPN) output stages with
a mismatch in gain and phase response for different polarities
of output current. It is difficult for the op amp manufacturer to
optimize compensation for all operating conditions.
MOUNTING PRECAUTIONS
1. Always use a heat sink. Even unloaded the PA60DK and
PA60EU can dissipate up to .4 watts.
2. Avoid bending the leads. Such action can lead to internal
damage.
3. Always fasten the tab of the EU package to the heat sink
before the leads are soldered to fixed terminals.
4. Strain relief must be provided if there is any probability of
axial stress to the leads.
SAFE OPERATING AREA (SOA)
The SOA curves combine the effect of all limits for this power
op amp. For a given application, the direction and magnitude
of the output current should be calculated or measured and
checked against the SOA curves. This is simple for resistive
loads but more complex for reactive and EMF generating
loads. The following guidelines may save extensive analyti-
cal efforts.
This data sheet has been carefully checked and is believed to be reliable,
SHANNON ROAD •
is assumed
ARIZONA 85741
omissions. All specifications are subject
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APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH
however, no responsibility
TUCSON,
for possible inaccuracies
•
or
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to change without notice.
4
PA60U REV F MARCH 2006 © 2006 Apex Microtechnology Corp.
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