PA98 查看數據表（PDF） - Cirrus Logic

零件编号

产品描述 (功能)

生产厂家

PA98

High Voltage Power Operational Amplifiers

Cirrus Logic 

PA98 • PA98A

OPERATING

CONSIDERATIONS

INTERNAL POWER DISSIPATION AND HEATSINK SELECTION

With the unique combination of high voltage and speed

of the PA98, traditional formulas for heatsink selection will

falsely lower the apparent power handling capability of this

amplifier. To more accurately predict operating temperatures

use Power Design1 revision 10 or higher, or use the following

procedure:

Find internal dissipation (PD) resulting from driving the

load. Use Power Design or refer to Apex Applications Note

1, General Operating Considertaions, paragraph 7. Find total

quiescent power (PDQ) by multiplying 0.025A by VSS (total

supply voltage). Find output stage quiescent power (PDQOUT)

by multiplying 0.001 by VSS.

Calculate a heatsink rating which will maintain the case at

85°C or lower.

Tc - Ta

RØSA =

-0.1°C/W

PD + PDQ

Where: TC = maximum case temperature allowed

TA = maximum ambient temperature encountered

Calculate a heatsink rating which will maintain output transistor

junctions at 150°C or lower.

RØSA =

TJ - Ta - (PD + PDQOUT) *RØJC

PD + PDQ

-0.1°C/W

Where: TJ = maximum junction temperature allowed.

RØJC= AC or DC thermal resistance from the specifica-

tion table.

Use the larger heatsink of these two calculations.

Power Design is an Excel spreadsheet available free from

www.apexmicrotech.com

AThPisEXdatMaIsChReeOt ThEasCHbeNenOcLaOreGfuYllyCOchRecPkOedRAanTdIOisNbe•lieTvEedLEtoPHbeOrNeliEab(l5e,2h0ow)e6ve9r,0n-o8r6e0sp0on•sibFiAlitXy (is5a2ss0u)me8d8f8or-3po3s2si9ble•inOaRccDuEraRciSes(o5r2o0m)iss6io9n0s.-8Al6l s0p1ec•ificEaMtioAnIsLarpersoudbljeictt@toacpheaxngmeiwcirtohoteutchno.tciocem.

PA98U REV I DECEMBER 2004 © 2004 Apex Microtechnology Corp.

5

Share Link: