Testing Conditions

TSH80-TSH81-TSH82

16/23

4

Testing Conditions

4.1

Layout precautions:

To use the TSH8X circuits in the best manner at high frequencies, some precautions have to be

taken for power supplies:

●

First of all, the implementation of a proper ground plane in both sides of the PCB is

mandatory for high speed circuit applications to provide low inductance and low resistance

common return.

●

Power supply bypass capacitors (4.7uF and ceramic 100pF) should be placed as close as

possible to the IC pins in order to improve high frequency bypassing and reduce harmonic

distortion. The power supply capacitors must be incorporated for both the negative and the

positive pins.

●

Proper termination of all inputs and outputs must be in accordance with output termination

resistors; then the amplifier load will be only resistive and the stability of the amplifier will

be improved.

All leads must be wide and as short as possible especially for op amp inputs and outputs

in order to decrease parasitic capacitance and inductance.

●

For lower gain application, attention should be paid not to use large feedback resistance

(>1k

Ω) to reduce time constant with parasitic capacitances.

●

Choose component sizes as small as possible (SMD).

●

Finally, on output, the load capacitance must be negligible to maintain good stability. You

can put a serial resistance the closest to the output pin to minimize its influence.

4.2

Maximum input level:

The input level must not exceed the following values:

●

Negative peak: must be greater than -Vcc+400mV.

●

Positive peak value: must be lower than +Vcc-400mV.

The electrical characteristics show the influence of the load on this parameter.

Figure 31. CCIR330 video line