Dear Sir or Madame,
I am an engineer at Airbus DS and we are using the THS4513-SP within one in our design. In more detail it is driving an ADC. The ADC applies the CM voltage (1.5V) to the THS4513-SP. The amplifier circuitry is as described in the datasheet. Furthermore the THS4513-SP is supplied with 0V and 3.3V. The amplifier input is fed by a 50ohm source. Nominal the 50ohm source feeds the amplifier with a signal power of -3dBm. Anyway, the application shows that in some cases, power levels of 17dBm could be fed to the amplifier. When I studied the datasheet in order to find out which input power levels can be handled by the amplifier the following information I have found:
ABSOLUTE MAXIMUM RATINGS
| ... | ... | ... |
| VI | Input voltage | ±VS |
| ... | ... | .. |
When I do understand the information correctly, the maximum input power level of the amplifier is as follows:
Assuming a sin-input voltage, the max. allowed sin- input voltage is oscillating between 0V and 3.3V which means in this application:
In_max_V = 1.5V + 1.5V*sin(2*Pi*f*t ) [volts]
Because the input impedance of the amplifier circutry is almost 50ohm, this would result into a maximum input power coming from a 50ohm source of:
In_max_P = 10 + 20*Log(Vpeak) = 10 + 20*Log(1.5V) = 13.522 dBm
Is my understanding correct?
Best Regards,
Daniel Popken
