AN569

Rev. 0.3

3

3. FM Testing Procedure

3.1. FM Tuning Frequency Range

3.1.1. Description

The test checks the lowest possible tuning frequency and the highest possible tuning frequency of Si4831/35/36/

20/24/25 FM receiver.

3.1.2. Conditions/Procedure

1. Connect test equipment as shown in Figure 1.

2. Configure the tuner in standard configuration.

3. Configure the audio analyzer:

a. Select Analyze.

b. Set Function = THD+N/SINAD.

i. Set Measurement Mode = SINAD.

ii. Set Unit = dB.

iii. Set Filter = A-weighting.

iv. Set Frequency Limit Low = 300 Hz.

v. Set Frequency Limit High = 15000 Hz.

4. Configure generator:

a. Set RF level = 0 dBμV.

b. Select FM Modulation.

i. Set FM Deviation = 22.5 kHz.

ii. Set source = LFGEN.

iii. Set LFGEN frequency = 1 kHz.

c. Enable modulation.

d. Enable carrier.

5. Slide band switch to select FM1 band for testing.

6. Turn tuning wheel to the lowest possible position.

7. Adjust signal generator RF (by 10 kHz step), until the measured SINAD reaches maximum level. Record

this RF frequency as the lowest tuning frequency Fmin.

8. Repeat for highest tuning frequency point Fmax.

9. Repeat for other FM band testing.

3.1.3. Pass Criteria

The FM tuning frequency range should be the FM band frequency range. Refer to the Si4831/35/36/20/24/25

DEMO Board User's Guide.