Application Hints

OPERATING NOTES

The signal source is usually capacitively coupled to the in-

put At higher frequencies a 0001 mF input capacitor is usu-

ally sufficient with larger values used at the lower frequen-

cies If the input signal is likely to be interrupted it may be

desirable to connect a 100 kX resistor between one input

and ground to stabilize the device In the single-ended

mode it is preferable to connect the resistor to the unused

input In the differential mode the resistor can be connected

to either input The addition of the 100 kX pull-down resistor

causes a loss of input sensitivity but prevents circuit oscilla-

tions under no signal (open circuit) conditions In addition in

the single ended mode a capacitor of 0001 mF should be

connected between the unused input and the ground plane

to provide a good high frequency bypass The capacitor

should be made larger for lower frequencies

The input waveform may be sinusoidal but below about 20

MHz the operation of the circuit becomes dependent on the

slew rate of the input rather than amplitude A square wave

input with a slew rate of greater than 20 V ms will permit

correct operation down to lower frequencies provided the

proper input coupling capacitor is provided

Schematic Diagrams

TLF5009 – 4

TLF5009 – 5

Typical Application

TLF5009 – 6

3