P r o d u c t I n n o v a t i o n F r o m



PA13U

PA13 • PA13A

POWER RATING

Notallvendorsusethesamemethodtoratethepowerhan-

dlingcapabilityofaPowerOpAmp.APEXratestheinternal

dissipation,whichisconsistentwithratingmethodsusedby

transistormanufacturersandgivesconservativeresults.Rat-

ingdeliveredpowerishighlyapplicationdependentandthere-

forecanbemisleading.Forexample,the135Winternaldis-

sipationratingofthePA13couldbeexpressedasanoutput

ratingof260Wforaudio(sinewave)oras440Wifusinga

singleendedDCload.Pleasenotethatallvendorsratemaxi-

mumpowerusinganinfiniteheatsink.

THERMAL STAbILITY

APEXhaseliminatedthetendencyofclassA/Boutputstages

toward thermal runaway and thus has vastly increased am-

plifierreliability.Thisfeature,notfoundinmostotherPower

OpAmps,waspioneeredbyAPEXin1981usingthermistors

whichassureanegativetemperaturecoefficientinthequies-

centcurrent.Thereliabilitybenefitsofthisaddedcircuitryfar

outweightheslightincreaseincomponentcount.

TYPICAL APPLICATION

4. +V

to–V

5. Ratingappliesiftheoutputcurrentalternatesbetweenbothoutputtransistorsataratefasterthan

60Hz.

6. Fulltemperaturerangespecificationsareguaranteedbutnot100%tested.