User`s manual

Output Circuitry Description

Refer to Figure 10-6. The output circuitry consists of an output amplifier,

attenuator, offset circuitry, and filter. The following describes the different

parts of the circuitry.

Attenuator The attenuator provides 30 dB attenuation in .01 dB steps for the output

voltage. The AFG automatically sets the attenuator to the appropriate value

dependent on the output amplitude selected by the user. The DC volts

function does not use the attenuator. For this function, the output of the

output DAC is directly output, through the output amplifier, to the

“Output” connector.

Filter The AFG provides a 250 kHz low-pass filter, 10 MHz low-pass filter, or no

filter. The filters are used to filter the high frequency components, such as

clock signals, of the output DAC’s output signal.

Output Amplifier The output amplifier provides the necessary current to drive output loads of

Ω and 75Ω loads applied to the “Output” connector. For matched loads,

the output amplitude are from -5.12 V to +5.11875 V. In addition, the

amplifier can also be set for open circuit or infinite loads applied to the

“Output” connector. For open circuit outputs, the amplitude range is twice

the matched load values.

Offset Circuitry This circuitry offsets the output amplifier to provide an offset voltage.

Figure 10-6. AFG Output Circuitry

Chapter 10 Block Diagram Description 451