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This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.

PA19U REV H FEBRUARY 1998 © 1998 Apex Microtechnology Corp.

protect against short-term fault conditions that result in high

power dissipation within the amplifier. If the conditions that

cause thermal shutdown are not removed, the amplifier will

oscillate in and out of shutdown. This will result in high peak

power stresses, destroy signal integrity, and reduce the reli-

ability of the device.

STABILITY

Due to its large bandwidth, the PA19 is more likely to oscil-

late than lower bandwidth power operational amplifiers. To

prevent oscillations a reasonable phrase margin must be

maintained by:

1. Selection of the proper phase compensation capacitor.

Use the values given in the table under external connec-

tions and interpolate if necessary. The phase margin can

be increased by using a larger capacitor at the expense of

slew rate. Total physical length (pins of the PA19, capaci-

tor leads plus printed circuit traces) should be limited to a

maximum of 3.5 inches.

2. Keep the external sumpoint stray capacitance to ground

at a minimum and the sumpoint load resistance (input and

feedback resistors in parallel) below 500Ω. Larger sumpoint

load resistances can be used with increased phase com-

pensation and/or by bypassing the feedback resistor.

3. Connect the case to any AC ground potential.

OPERATING

CONSIDERATIONS

PA19 • PA19A