Keysight U8903B, Service Manual

Page: 78 / 165

4 Performance Verification for Digital Generator and Digital Analyzer
78 Keysight U8903B Service Guide
Unbalanced input sampling rate accuracy verification
This test measures the sampling rate accuracy on the unbalanced digital audio input of the
U8903B using the Keysight 53132A/53220A frequency counter and its own digital audio
unbalanced generator to ensure that it is within the published specification.
1 Connect 53132A/53220A Frequency Counter input channel 1 to the U8903B
unbalanced digital output channel using the SPDIF or 75
Ω
impedance cable as shown
in Figure 4-7 .
Figure 4-7 Keysight 53132A/53220A to U8903B unbalanced digital output for unbalanced input sampling
rate accuracy verification
2 Configure the Keysight 53132A/53220A frequency counter as follows:
– Preset the equipment
– Channel 1 and channel 2 input impedance: 50
Ω
– Frequency measurement start arming source: Immediate
– Frequency measurement stop arming source: Timer
– Frequency arming and measurement gate time: 0.5 s
3 Configure the U8903B digital output channel to be tested as follows:
– Preset the U8903B
– Digital output type: Unbalanced
– Digital output voltage: 2.5 V
– Digital output sampling rate: 48 kHz
– Digital output AES audio resolution: 24 bits
– AES output: ON
– Optical output state: OFF
– Digital output function: SINE waveform
– SINE waveform frequency: 1 kHz
Table 4-9 Unbalanced input sampling rate accuracy specification
Unbalanced input sampling rate accuracy specification Equipment used
±
5 ppm Frequency counter
SPDIF or 75 Ω
impedance cable
53132A/53220A
frequency counter
U8903B
unbalanced
digital output