AN646: Si477x Evaluation Board Test Procedure

AN646
S i477 X E VALUATION B OAR D TEST P ROCEDURE
1. Introduction
This document describes the test procedures used in Silicon Laboratories for the Si477x evaluation boards (EVB). It
is also intended to enable customers to exactly replicate Silicon Laboratories' test environment so that variances in
customers' and Silicon Laboratories' measured results can be accurately compared. This document covers AM,
FM, RDS and weather band tests for the Si477x receivers. The pass/fail criteria for each test are provided in the
respective data sheets. The Si477x evaluation boards and software provide a platform to program, test, and
operate the Si477x devices. The system consists of two boards: a baseboard and an RF daughter card. The
baseboard provides all necessary support functions, including a USB-based programming interface, analog audio.
The RF daughter card changes for each device. Refer to the individual EVB User's Guides for detailed explanations
of the EVB hardware and software.
2. FM Tune Testing
This section covers testing the FM specifications for the Si477x receiver. Table 1 provides a summary of FM tests and
equipment.
Table 1. FM Tuner Test Equipment
Test
Equipment
Sensitivity
AM Suppression
Audio Output Voltage
Audio THD
Audio SNR
Stereo Separation
Audio Output L/R Imbalance
Audio SINAD
Stereo Pilot Rejection
Rohde & Schwarz UPV Audio Analyzer
Rohde & Schwarz SMB + Stereo/RDS Signal Generator #1
USB Power Supply*
Image Rejection
Adjacent/Alternate Channel Rejection
IP3
Equipment above plus:
Rohde & Schwarz SMB Signal Generator #2
Mini Circuits ZFRSC-42-S+ 0-4.2GHz Combiner
Note: The user has the option of powering up the EVB through USB, L2 (external 9V), or J1/J2 (two Agilent E3646A power
supplies).
Rev. 0.1 12/11
Copyright © 2011 by Silicon Laboratories
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R&S SMB Generator #1
R&S SMB Generator #2
PC with
USB
USB
Quark Baseboard
Si477x Daughterboard
Antenna (J1)
J64 L/R_LINE_OUT
J55 Head Phone Out
c
v
9V PS USB
POWER_SELECT (SW1)
9V L2
G VD VA G G VIO2 VIO1 G
Power #2
Ch1
Combiner
Ch2
R&S UPV Audio Analyzer
Power #1
AG E3646A
Power Supply1
AG E3646A
Power Supply2
Figure 1. Si477x FM Tuner Measurement Setup
Typically for the single tuner the baseboard is powered using USB power. When the switch is set to the USB, the
tuner voltage is set by default to VA = 5 V VD = VIO1 = VIO2 = 3.3 V. For higher current requirements (typically
when the daughter card has more than one tuner), the switch can be set to 9 V, and a 9 V adapter can be
connected to the 9 V L2 socket of the baseboard. To use any voltage other than the default, two external power
supplies can be connected to the Power#1 and #2 connectors. If the external power supply is used, the jumpers
J57, J58, J59, and J60 should be set to the TERM side. For details, refer to the EVB user’s guide.
2.1. FM Tuner Testing Calibration
During testing power combiner and cable losses must be calibrated and factored into each measurement. The
calibration is performed by setting the Generator#1 at 98 MHz and 0 dBm and measuring the RF power at the DUT.
The calibration factor is either programmed as an offset to the generator or manually compensated during
measurement. All the levels specified in this document are the levels that should be set at the DUT.
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2.2. FM Tuner Configuration
The FM tuner is set to following common configuration. The user can run the FM tests by configuring the FM
frequency and using the power up defaults (by just booting up the tuner using GUI). However, the following setups
enhance the measurement speed, and can be used if the user is running automated tests.
"Appendix A—Setting properties using the Audio GUI" on page 42 describes the methods for setting the property
values using the Audio GUI.
Property
Value
Property Address
Property Value to Set
Frequency
98 MHz
Volume
Maximum
0x0300
0x003F
Stereo Separation RSSI
Limit (max)
Stereo Separation RSSI
Limit (min)
55 dBµv (0x37 8 MSBs)
0x3500
0x3719
Hi-Cut & Hi-Blend
Disabled
See below
Fast Attack and Release
Enabled
See Below
25 dBµv (0x19 8 LSBs)
2.2.1. Disable Hi-Cut and Hi-Blend
The Hi-Cut and Hi-Blend is disabled by setting following properties:
setProperty( 0x3601, 0xB4B4); //FM_HICUT_FAST_RSSI_CUTOFF_FREQ
setProperty( 0x3605, 0xB4B4); //FM_HICUT_SLOW_RSSI_CUTOFF_FREQ
setProperty( 0x3609, 0xB4B4); //FM_HICUT_FAST_MULTIPATH_CUTOFF_FREQ
setProperty( 0x360D, 0xB4B4); //FM_HICUT_SLOW_MULTIPATH_CUTOFF_FREQ
setProperty( 0x3611, 0xB4B4); //FM_HICUT_FAST_USN_CUTOFF_FREQ
setProperty( 0x3615, 0xB4B4); //FM_HICUT_SLOW_USN_CUTOFF_FREQ
setProperty( 0x3701, 0xB4B4); //FM_HIBLEND_FAST_RSSI_CUTOFF_FREQ
setProperty( 0x3705, 0xB4B4); //FM_HIBLEND_SLOW_RSSI_CUTOFF_FREQ
setProperty( 0x3709, 0xB4B4); //FM_HIBLEND_FAST_MULTIPATH_CUTOFF_FREQ
setProperty( 0x370D, 0xB4B4); //FM_HIBLEND_SLOW_MULTIPATH_CUTOFF_FREQ
setProperty( 0x3711, 0xB4B4); //FM_HIBLEND_FAST_USN_CUTOFF_FREQ
setProperty( 0x3715, 0xB4B4); //FM_HIBLEND_SLOW_USN_CUTOFF_FREQ
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2.2.2. Set Fast Attack and Release
The attack and release times for Blend, Hi-cut and Hi-blend based on RSSI, multipath and USN can be sped up by
setting the following properties.
RSSI Based Blend
setProperty( 0x3502, 0x0010);//FM_BLEND_FAST_RSSI_ATTACK_TIME
setProperty( 0x3503, 0x0010);//FM_BLEND_FAST_RSSI_RELEASE_TIME
setProperty( 0x3506, 0x0010);//FM_BLEND_SLOW_RSSI_ATTACK_TIME
setProperty( 0x3507, 0x0010);//FM_BLEND_SLOW_RSSI_RELEASE_TIME
Multipath Based Blend
setProperty( 0x350A, 0x0010);//FM_BLEND_FAST_MULTIPATH_ATTACK_TIME
setProperty( 0x350B, 0x0010);//FM_BLEND_FAST_MULTIPATH_RELEASE_TIME
setProperty( 0x350E, 0x0010);//FM_BLEND_SLOW_MULTIPATH_ATTACK_TIME
setProperty( 0x350F, 0x0010);//FM_BLEND_SLOW_MULTIPATH_RELEASE_TIME
Blend based on USN
setProperty( 0x3512, 0x0010);//FM_BLEND_FAST_USN_ATTACK_TIME
setProperty( 0x3513, 0x0010);//FM_BLEND_FAST_USN_RELEASE_TIME
setProperty( 0x3516, 0x0010);//FM_BLEND_SLOW_USN_ATTACK_TIME
setProperty( 0x3517, 0x0010);//FM_BLEND_SLOW_USN_RELEASE_TIME
Hicut Based on RSSI
setProperty( 0x3602, 0x0010);//FM_HICUT_FAST_RSSI_ATTACK_TIME
setProperty( 0x3603, 0x0010);//FM_HICUT_FAST_RSSI_RELEASE_TIME
setProperty( 0x3606, 0x0010);//FM_HICUT_SLOW_RSSI_ATTACK_TIME
setProperty( 0x3607, 0x0010);//FM_HICUT_SLOW_RSSI_RELEASE_TIME
Hicut Based on Multipath
setProperty( 0x360A, 0x0010);//FM_HICUT_FAST_MULTIPATH_ATTACK_TIME
setProperty( 0x360B, 0x0010);//FM_HICUT_FAST_MULTIPATH_RELEASE_TIME
setProperty( 0x360E, 0x0010);//FM_HICUT_SLOW_MULTIPATH_ATTACK_TIME
setProperty( 0x360F, 0x0010);//FM_HICUT_SLOW_MULTIPATH_RELEASE_TIME
Hicut based on USN
setProperty( 0x3612, 0x0010);//FM_HICUT_FAST_USN_ATTACK_TIME
setProperty( 0x3613, 0x0010);//FM_HICUT_FAST_USN_RELEASE_TIME
setProperty( 0x3616, 0x0010);//FM_HICUT_SLOW_USN_ATTACK_TIME
setProperty( 0x3617, 0x0010);//FM_HICUT_SLOW_USN_RELEASE_TIME
Hiblend based on RSSI
setProperty( 0x3702, 0x0010);//FM_HIBLEND_FAST_RSSI_ATTACK_TIME
setProperty( 0x3703, 0x0010);//FM_HIBLEND_FAST_RSSI_RELEASE_TIME
setProperty( 0x3706, 0x0010);//FM_HIBLEND_SLOW_RSSI_ATTACK_TIME
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setProperty( 0x3707, 0x0010);//FM_HIBLEND_SLOW_RSSI_RELEASE_TIME
Hiblend based on Multipath
setProperty( 0x370A, 0x0010);//FM_HIBLEND_FAST_MULTIPATH_ATTACK_TIME
setProperty( 0x370B, 0x0010);//FM_HIBLEND_FAST_MULTIPATH_RELEASE_TIME
setProperty( 0x370E, 0x0010);//FM_HIBLEND_SLOW_MULTIPATH_ATTACK_TIME
setProperty( 0x370F, 0x0010);//FM_HIBLEND_SLOW_MULTIPATH_RELEASE_TIME
Hiblend based on USN
setProperty( 0x3712, 0x0010);//FM_HIBLEND_FAST_USN_ATTACK_TIME
setProperty( 0x3713, 0x0010);//FM_HIBLEND_FAST_USN_RELEASE_TIME
setProperty( 0x3716, 0x0010);//FM_HIBLEND_SLOW_USN_ATTACK_TIME
setProperty( 0x3717, 0x0010);//FM_HIBLEND_SLOW_USN_RELEASE_TIME
setProperty( 0x2203, 0x0001);// AM_CHBW_SQ_WIDENING_TIME
setProperty( 0x2204, 0x0001); //AM_CHBW_SQ_NARROWING_TIME
setProperty( 0x2208, 0x0001); //AM_CHBW_ASSI_WIDENING_TIME
setProperty( 0x2209, 0x0001); //AM_CHBW_ASSI_NARROWING_TIME
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2.3. Analyzer Configuration
The analyzer is configured in analog mode for the tests. The following configuration is common for all tests:

Instrument: Analog
 Bandwidth: 22 kHz
 Pre Filter: OFF
 Channel Coupling: AC
2.4. FM Test Procedures
The following procedures measure analog audio output.
2.4.1. Sensitivity
Sensitivity of a receiver is a measure of its ability to receive weak signals and produce an audio frequency output of
usable magnitude and acceptable quality. Sensitivity may be defined with respect to many different characteristics
of the output signal. For the purposes of our testing, sensitivity is the minimum RF level required to produce an
audio output with a specified signal-to-noise and distortion ratio (SINAD), of 26 dB.
1. Configure the audio analyzer:
a. Function: THD+N/SINAD
b. Measurement Mode = SINAD
c. Fundamental = 1000 Hz Fixed
d. Filter = OFF
e. Frequency Limit Low = 30 Hz
f.
Frequency Limit High = 15000 Hz
g. Function Setting = Off (for quick measurement) or Average (for accurate measurement)
h. Set Unit = dB.
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Select FM Modulation.
c. Set FM Deviation = 22.5 kHz.
d. Set Source = LFGEN (Internal). Set LFGEN frequency = 1 kHz.
e. Enable modulation. Enable carrier.
3. Disable generator #2.
4. Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 26 dB.
5. Sensitivity (dBµV) = VRF0.
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2.4.2. THD
The total harmonic distortion, or THD, is a measurement of the harmonic distortion present at the audio output and
is defined as the ratio of the sum of the powers of all harmonic components calculated in RMS fashion to the power
of the fundamental. The THD measurement is performed for both mono and the stereo signals for both normal
(60 dBµV) and strong signal (120 dBµV).
1. Configure the audio analyzer:
a. Function= THD
b. Measurement Mode= All di
c. Fundamental= 1000 Hz Fixed
d. Equalizer= OFF
e. Function Setting = Off (for quick measurement) or Average (for accurate measurement)
f.
Select Unit = %.
2. For mono measurement: Configure generator #1
a. Set carrier frequency = 98.0 MHz.
b. Select FM Modulation.
c. Set FM Deviation = 75 kHz.
d. Set RF level = 60 dBµV. (120 dBµV for strong signal)
e. Set source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
f.
Enable modulation. Enable carrier.
OR
1. For stereo measurement: Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV (120 dBµV for strong signal).
b. Select Stereo Modulation.
c. Deviation=67.5 kHz.
d. Pilot Deviation=6.75 kHz.
e. Mode= L=1 R=0.
f.
Source = LFGEN. Set LFGEN frequency = 1 kHz.
g. Pre-emphasis = OFF.
h. Enable modulation. Enable carrier.
2. Disable generator #2.
3. Record THD (%).
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2.4.3. SNR
The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio frequency output voltage
due to the signal to that due to random noise. The SNR measurement is performed for both mono and the stereo
signal. In the mono SNR test is performed for both normal (60 dBµV) and strong signal (120 dBµV).
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = Level Noise.
c. Set Units = dB.
d. Fundamental = 1000 Hz fixed.
e. Set Frequency Limit Low = 30 Hz.
f.
Set Frequency Limit Upper = 15000 Hz.
g. Function Setting = Off (for quick measurement) or Average (for accurate measurement).
2. For mono measurement: Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV (120 dBµV for strong signal test).
b. Select FM Modulation.
c. Set FM Deviation = 22.5 kHz. Set source = LFGEN (internal).
d. Set LFGEN frequency = 1 kHz.
e. Enable modulation. Enable carrier.
f.
Disable generator #2.
OR
1. For stereo measurement: Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV.
b. Select Stereo Modulation.
c. Deviation = 67.5 kHz.
d. Pilot Deviation = 6.75 kHz.
e. Mode= L=1 R=0.
f.
Source = LFGEN. Set LFGEN frequency = 1 kHz.
g. Pre-emphasis = OFF
h. Enable modulation. Enable carrier.
2. Record SNR (dB) = Input RMS(dBV) – Level Noise (dBV).
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2.4.4. SINAD
Signal to noise and distortion (SINAD) is similar to signal to noise ratio, but includes distortion and is a ratio of
"signal plus noise plus distortion" to "noise plus distortion." To make the SINAD measurement, a signal modulated
with an audio tone is entered into the receiver. A measurement of the whole signal, i.e., the signal plus noise plus
distortion, is made by the audio analyzer. The audio tone is then removed by the analyzer and the remaining noise
and distortion is measured. SINAD test is performed for both mono and stereo signals. Mono SINAD test is
performed for normal (60 dBµV) and strong signals (120 dBµV).
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Fundamental: 1000 Hz Fixed.
d. Filter = OFF.
e. Frequency Limit Low = 30 Hz.
f.
Frequency Limit High = 150 Hz.
g. Function Setting: Off (for quick measurement) or Average (for accurate measurement).
h. Select Unit = dB.
2. For mono measurement: Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV (120 dBµV for strong signal).
b. Select FM Modulation.
c. Set FM Deviation = 22.5 kHz.
d. Set Source = LFGEN (internal).
e. Set LFGEN frequency = 1 kHz.
OR
1. For stereo measurement: Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV.
b. Select Stereo Modulation.
c. Set Deviation = 67.5 kHz.
d. Pilot Deviation = 6.75 kHz.
e. Mode = L=1 R=0
f.
Set source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
g. Enable modulation. Enable carrier.
2. Enable modulation. Enable carrier.
3. Disable generator #2.
4. Record SINAD (dB).
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2.4.5. AM Suppression
AM suppression of an FM receiver represents the ability of the receiver to reject AM of the input signal. AM might
be a result of fading multi-path signals, aircraft flutter, AM at the transmitter, and AM introduced in the receiver by
pass-band limitations and mistuning. AM suppression is measured as a ratio of voltage measured with an FM
modulated signal to that of an AM modulated signal.
Configure the audio analyzer:
1. Select Analyze.
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV. Select FM Modulation.
b. Set FM Deviation = 22.5 kHz. Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
c. Enable modulation. Enable carrier.
3. Record the audio level, VAUDIO0.
4. Turn off generator #1 FM modulation.
5. Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV.
b. Select AM Modulation. Set Depth = 30%.
c. Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
d. Enable modulation. Enable carrier.
6. Record the audio level, VAUDIO1.
7. AM Suppression (dB) = VAUDIO0 – VAUDIO1.
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2.4.6. Audio Output Voltage
Audio output voltage is measured as an RMS value under standard operating conditions.
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = VRMS.
d. Set Frequency Mode = FIX: 1 kHz.
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz. Set RF level = 60 dBµV. Select FM Modulation.
b. Set FM Deviation = 22.5 kHz. Set Source = LFGEN (internal).
c. Set LFGEN frequency = 1 kHz.
3. Enable modulation. Enable carrier.
4. Audio level (VRMS) = measured VAUDIO0 from Audio Analyzer.
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2.4.7. Audio L/R Imbalance
The level difference between the two stereo channels is a quality criterion of the tuner because level differences
shift the center for stereo sound impression. Audio L/R imbalance is the ratio of left to right channel output voltage.
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Set RF level = 60 dBµV.
c. Select FM Modulation.
d. Set FM Deviation = 75 kHz.
e. Set RF level = 60 dBµV.
f.
Set Source = LFGEN (internal).
g. Set LFGEN frequency = 1 kHz.
h. Enable modulation. Enable carrier.
3. Left channel audio level (dBV) = VAUDIOL.
4. Right channel audio level (dBV) = VAUDIOR.
5. Audio L/R imbalance (dB) = abs (VAUDIOL - VAUDIOR).
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2.4.8. Audio Stereo Separation
Crosstalk occurs when signal components of a channel are coupled into another audio channel. This reduces
channel separation and thus impairs the stereo effect. Audio stereo separation is the level ratio of the wanted
signal in a channel to the unwanted signal coupled into the other channel. Only the left channel is modulated and
the levels are measured in both channels to obtain the ratio. To suppress the noise components, a selective
measurement is carried out.
1. Configure the audio analyzer:
2. Select Analyze.
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
3. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Set RF level = 60 dBµV.
c. Select Stereo Modulation.
d. Set FM Deviation = 67.5 kHz.
e. Set L = 1, R = 0.
f.
Set Source = LFGEN (internal).
g. Set LFGEN frequency = 1 kHz.
h. Set Pre-emphasis = 75 µs.
i.
Set Pilot = ON.
j.
Set Pilot Deviation = 6.75 kHz.
k. Enable modulation.
l.
Enable carrier.
4. Left channel audio level (dBV) = VAUDIOL.
5. Right channel audio level (dBV) = VAUDIOR.
6. Audio Stereo Separation (dB) = abs (VAUDIOL – VAUDIOR).
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2.4.9. Stereo Pilot Rejection
A pilot tone is transmitted at 19 kHz to identify stereo broadcast transmissions. In order not to disturb instruments
such as amplifiers and recorders connected to the tuner, the pilot tone and its subcarriers must be sufficiently
suppressed in the tuner. Stereo pilot rejection is the quality criterion of a tuner that is measured as the ratio of
wanted audio frequency voltage to pilot frequency voltage according to the equation:
Pilot Rejection = 1 kHz + 20 x log ( pilot/ f) – V19 kHz)
Where f is FM frequency deviation and pilot is pilot frequency deviation.
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
e. Set Filter = OFF
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Set RF level = 60 dBµV.
c. Select Stereo Modulation
d. Set FM Deviation = 67.5 kHz.
e. Set Mode L = R.
f.
Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
g. Set Pre-emphasis = 75 µs.
h. Set Pilot = ON.
i.
Set Pilot Deviation = 6.75 kHz.
j.
Enable modulation. Enable carrier.
3. Audio 1 kHz level (dBV) = V1 kHz.
4. Configure audio analyzer frequency mode = FIX: 19 kHz.
5. Audio 19 kHz level (dBV) = V19kHz.
6. Pilot Rejection (relative to pilot) (dB) = V1 kHz – V19kHz + 20 x log10 (pilot/ f) = V1kHz – V19kHz – 20.
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2.4.10. IP3
Intermodulation distortion in the detected or decoded audio-frequency signal may be caused by non-linearity in the
radio-frequency, intermediate-frequency, and detector stages of the receiver. A good measure of intermodulation
distortion is IP3. IP3 is the theoretical RF level at which two blockers (VRF1), offset from the desired frequency by
f and 2 f, and their intermodulation product (VRF0) would be of the same amplitude, according to the equation IP3
= VRF1 + ½(VRF1 – VRF0). VRF0 is the 26 dB SINAD sensitivity level at the fundamental frequency. VRF1 is the
blocker level required to produce an inter-modulation product at the same sensitivity level.
In our test:
f1 = 98.4 MHz (blocker #1) f2 = 98.8 MHz (blocker #2)
2 x f1 – f2 = 98.0 MHz (tuner frequency)
1. The IP3 test requires that after configuring the tuner in standard configuration, the tuner should be set at
maximum gain. To achieve maximum gain,
a. Boot the tuner in standard configuration.
b. Turn OFF RF output of the generators.
c. Turn OFF the Tuner AGC.
d. Send the following command.
i. setProperty (0x0710 0x3F)
e. (OR) Turn OFF tuner AGC from the Audio GUI.
i. In the Audio GUI, select WindowProperties menu. This launches the properties window.
ii. In properties Window Select Property Category AM:AGC Properties.
iii. In AGC Properties set AGC State Off.
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2. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Filter = OFF.
d. Frequency Limit Low = 30 Hz, Frequency Limit High = 15000 Hz.
e. Select Unit = dB.
f.
Function Setting = Off (for quick measurement) or Average (for accurate measurement).
3. Configure generator #1:
a. Set carrier frequency = 98.4 MHz.
b. Set RF level = 70 dBµV.
c. Select FM Modulation.
d. Set FM Deviation = 22.5 kHz. Set Source = LFGEN (internal).
e. Set LFGEN frequency = 1 kHz.
f.
Enable modulation. Enable carrier.
4. Configure generator #2:
a. Set carrier frequency = 98.8 MHz.
b. Set RF level = 70 dBµV.
c. Disable modulation. Enable carrier.
5. Simultaneously adjust the generator #1 and generator #2 RF level, VRF1, until SINAD = 26 dB.
6. IP3 (dBµV) = VRF1 + ½ (VRF1 - VRF0). VRF0 is the level from sensitivity test.
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2.4.11. Image Rejection
Receivers respond to unwanted signals at the intermediate frequency, at the image frequency, and at harmonics of
the signal frequency and other frequencies associated with harmonics of the local oscillator frequency.
To understand the concept of image frequency, refer to Figure 2.
Figure 2. Image Frequency Spectra
1. The image injection side can be positive or negative depending on the frequency of tuner. For the frequency
mentioned in this test routine, the injection side is negative (image rejection at negative 256 kHz). If the user
needs to use other frequency value, they can read the image injection side from the chip and decide whether to
use positive or negative image offset (refer to " Appendix B—Reading Image Offset Side Using the Audio GUI"
on page 44).
2. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
e. Filter = OFF
3. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Set RF level = 60 dBµV.
c. Select FM Modulation.
d. Set FM Deviation = 22.5 kHz.
e. Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
f.
Enable modulation. Enable carrier.
4. Vary the Generator#1 RF level and measure using the analyzer to reach a target sinad level of 26 dB. The
resulting RF level is VRF1.
5. Set the RF level of generator#1 to VRF2 = VRF1 +3 dB
6. Configure generator #2:
a. Set carrier frequency = 97.744 MHz (image at –256 kHz)
b. Select FM Modulation
c. Set FM Deviation = 22.5 kHz.
d. Set Source = LFGEN (internal). Set LFGEN frequency = 400 Hz.
e. Enable generator. Enable carrier.
7. Set generator#2 initially at VRF2. Increase the RF level of the image (generator #2) until SINAD drops back to
26 dB. Call this RF level VRF3.
8. Image rejection (dB) = VRF3 – VRF2.
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2.4.12. Adjacent/Alternate Channel Rejection
Rejection is a measure of the performance of a radio receiver to respond only to the tuned transmission (such as a
radio station) and reject other signals nearby, such as another broadcast on an adjacent channel. The adjacent/
alternate channel rejection tests are performed at –100 , –200, and –400 kHz offsets.
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Filter = OFF.
d. Frequency Limit Low = 30 Hz.
e. Frequency Limit High = 15000 Hz.
f.
Set Frequency Mode = FIX: 1 kHz.
g. Function Setting = Off (for quick measurement) or Average (for accurate measurement).
h. Select Unit = dB.
2. Configure generator #1:
a. Set carrier frequency = 98.0 MHz.
b. Set RF level VRF0 = 40 dBµV.
c. Select FM Modulation.
d. Set FM Deviation = 22.5 kHz. Set source = LFGEN (internal).
e. Set LFGEN frequency = 1 kHz.
f.
Enable modulation. Enable carrier.
3. Configure generator #2:
a. Set carrier frequency = 97.9 or 97.8 MHz (adjacent channel) or Set carrier frequency = 97.8 or 97.6 MHz
(alternate channel).
b. Select FM Modulation.
c. Set FM Deviation = 22.5 kHz.
d. Source = LFGEN. Set LFGEN frequency = 400 Hz.
e. Enable modulation. Enable carrier.
4. Adjust generator #2 RF level, VRF1, until the SINAD level is 26 dB.
5. Rejection (dB) = VRF1 – VRF0.
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3. AM Tuner Testing
This section covers testing the AM specs for the Si477x receiver. Table 2 provides a summary of tests and
equipment.
Table 2. AM Tuner Test Equipment
Test
Equipment
Sensitivity
Audio Output Voltage
Audio THD
Audio SNR
Audio SINAD
Rohde & Schwarz UPV Audio Analyzer
Rohde & Schwarz SMB Generator #1
USB Power Supply*
Image Rejection
Adjacent/Alternate Channel Rejection
IP2
IP3
Equipment above plus:
Rohde & Schwarz SMB Signal Generator #2
Rohde & Schwarz Signal Generator #3 (required for IP2/IP3 tests)
Mini Circuits ZSC-3-2 0-30MHz or equivalent 3 to 1 combiner
(required for IP2/IP3) OR
Mini Circuits ZFRSC-42-S+ 0-4.2GHz or 2 to 1 Combiner (if not
running the IP2/IP3 tests)
*Note: The user has the option of powering up the EVB through USB, L2 (external 9V), or J1/J2 (two Agilent E3646A
power supplies).
R&S SMB Generator #3
(Required for IP2/IP3 tests)
PC with
USB
R&S SMB Generator #1
R&S SMB Generator #2
USB
Quark Baseboard
Si477x Daughterboard
Antenna (J33)
J64 L/R_LINE_OUT
J55 Head Phone Out
9V PS USB
POWER_SELECT (SW1)
9V L2
G VD VA G G VIO2 VIO1 G
Power #2
Ch1
Power Combiner
Ch2
R&S UPV Audio Analyzer
Power #1
AG E3646A
Power Supply1
AG E3646A
Power Supply2
Figure 3. Si477x AM Tuner Measurement Setup
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3.1. AM Tuner Testing Calibration
During testing power combiner and cable losses must be calibrated and factored into each measurement. The
calibration is performed by setting the Generator#1 at 1 MHz and 0 dBm and measuring the RF power at the DUT.
The calibration factor is either programmed as an offset to the generator or manually compensated during
measurement. All the levels specified in this document are the levels that should be set at the DUT.
3.2. AM Tuner Configuration
The AM tuner is set to following common configuration. It is not necessary to set the following properties during AM
testing. The user can run the AM tests by configuring the AM frequency and using the power up defaults (by just
booting up the tuner using GUI). However, the following setups enhance the measurement speed, and can be used
if the user is running automated tests.
Appendix A describes the methods for setting the property values using the Audio GUI.
20
Property
Value
Property Address
Property Value to Set
Input Frequency
1000 kHz
Volume
63 (max)
0x0300
0x003F
Hi-cut
Disabled
0x3104
0x3232
Softmute
OFF
0x0400
0x0000
AGC Mode
Fast
0x070C
0x070D
0x0008
0x0008
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3.3. AM Tuner Testing Procedures
The following procedures describe AM tuner measurements.
3.3.1. Sensitivity
Sensitivity of a receiver is a measure of its ability to receive weak signals and produce an audio frequency output of
usable magnitude and acceptable quality. Sensitivities may be defined with respect to many different
characteristics of the output signal. For the purposes of our testing, sensitivity is the minimum RF level required to
produce an audio output with a specified signal-to-noise and distortion ratio (SINAD), of 20 dB. Note that the
sensitivity measurement is defined with respect to SINAD and not SNR. Descriptions for these two measurements
will be given in the following sections.
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Set Unit = dB.
d. Set Filter = OFF.
e. Set Frequency Limit Low = 30 Hz.
f.
Set Frequency Limit High = 15000 Hz.
g. Fundamental = 1000 Hz fixed function.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Select AM Modulation.
c. Set AM Modulation Depth = 30%.
d. Set source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
e. Enable AM modulation. Enable RF carrier.
3. Disable generator #2.
4. Disable generator #3.
5. Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 20 dB.
6. Sensitivity = VRF0 (dBµV).
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3.3.2. Radiated Sensitivity
In order to avoid environmental noise issues, it is best to conduct radiated tests in a shielded room.
1. Connect test equipment as shown in Figure 4.
2. Configure the tuner:
a. Set frequency = 1 MHz.
b. Set volume = 63.
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 #1:
a. Set carrier frequency = 1 MHz.
b. Select AM Modulation.
i. Set AM Modulation Depth = 30%.
ii. Set Source = LFGEN.
iii. Set LFGEN frequency = 1 kHz.
c. Enable AM modulation.
d. Enable RF carrier.
5. Disable generator #2.
6. Disable generator #3.
7. Disconnect the USB connection through the GUI while keeping the device ON.
8. Remove the laptop from the room in which the testing is conducted.
9. Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 20 dB ± 1 dB.
10.Sensitivity (µV) = VRF0.
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Audio
Analyzer
RXS
R&S SMB Generator 1
Power
Combiner
R&S SMB Generator 2
RCA
Cable
J6
AM
IN
RCA
OUT
Air Loop Antenna - TX
Si477x
Daughterboard
Air Loop Antenna - RX
Quark
Base board
USB
60 cm
J79
USB
Cable
J76
EXT SW1
pwr
USB
pwr
J77
EXT
Jack
PC
with USB
port
Figure 4. Test Setup for AM Radiated Sensitivity
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3.3.3. SNR
The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio frequency output voltage
due to the signal to that due to random noise. This test is performed at standard (30%) and High (90%) modulation
depth as well as normal (74 dBµV) and strong (100 dBµV) signal levels.
1. Configure the audio analyzer to record noise.
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = Level Noise.
c. Set Unit = dB.
d. Set Frequency Mode = FIX: 1 kHz.
e. Set Filter = OFF.
f.
Set Frequency Limit Low = 30 Hz.
g. Set Frequency Limit High = 15000 Hz.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Set RF level = 74 dBµV (100 dBµV for strong signal).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%. (90% for High)
e. Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz.
f.
Enable AM modulation. Enable RF carrier.
3. Disable generator #2.
4. Disable generator #3.
5. Record Noise (dB) from analyzer.
6. Record SNR (dB) = Input RMS(dBV) – Level Noise (dBV).
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3.3.4. THD
The total harmonic distortion, or THD, is a measurement of the harmonic distortion present at the audio output and
is defined as the ratio of the sum of the powers of all harmonic components calculated in RMS fashion to the power
of the fundamental. This test is performed at standard (30%) and high (90%) modulation depth as well as normal
(74 dBµV) and strong (100 dBµV) signal levels.
1. Configure the audio analyzer:
a. Function= THD.
b. Measurement Mode= All di.
c. Fundamental= 1000 Hz fixed.
d. Equalizer = OFF.
e. Function Setting = Off (for quick measurement) or Average (for accurate measurement).
f.
Select Unit = %.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Set RF level = 74 dBµV (100 dBµV for strong signal).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30% (90% for high Modulation depth measurement).
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 1 kHz.
g. Enable AM modulation. Enable RF (carrier).
3. Disable generator #2.
4. Disable generator #3.
5. Record THD (%).
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3.3.5. SINAD
Signal to noise and distortion (SINAD) is similar to signal to noise ratio, but includes distortion. A measurement of
the whole signal, i.e., the signal plus noise plus distortion, is made by the audio analyzer. The audio tone is then
removed by the analyzer and the remaining noise and distortion is measured. This test is performed at standard
(30%) and High (90%) modulation.
depth
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Fundamental: 1000 Hz fixed.
d. Filter = OFF.
e. Frequency Limit Low = 30 Hz.
f.
Frequency Limit High = 15000 Hz.
g. Function Setting: Off (for quick measurement) or Average (for accurate measurement).
h. Select Unit = dB.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz
b. Set RF level = 74 dBµV (100 dBµV for strong signal).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30% (90% for high Modulation depth measurement).
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 1 kHz.
g. Enable AM modulation. Enable RF (carrier).
3. Enable modulation. Enable carrier.
4. Disable generator #2.
5. Disable generator #3.
6. Record SINAD (dB).
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3.3.6. Output Voltage
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = VRMS.
d. Set Frequency Mode = FIX: 1 kHz.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Set RF level = 74 dBµV.
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 1 kHz.
g. Enable AM modulation. Enable RF (carrier).
3. Disable generator #2.
4. Disable generator #3.
5. Record audio level (Vrms) from the analyzer.
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3.3.7. Adjacent/Alternate Channel Rejection
Rejection is a measure of the performance of a radio receiver to respond only to the tuned transmission (such as a
radio station) and reject other signals nearby, such as another broadcast on an adjacent channel. Adjacent channel
rejection measures the interference from an unwanted signal present one band spacing away (9 kHz away).
Alternate channel rejection measures the interference from an unwanted signal present two band spacing away
(18 kHz away).
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = SINAD.
c. Filter = OFF
d. Frequency Limit Low = 30 Hz.
e. Frequency Limit High = 15000 Hz
f.
Set Frequency Mode = FIX: 1 kHz.
g. Select Unit = dB.
2. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Set RF level VRF0= 20 dBµV.
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 1 kHz.
g. Enable AM modulation. Enable RF carrier.
3. Disable generator #3.
4. Configure generator #2:
a. Set carrier frequency = 0.991 MHz (adjacent channel), or
b. Set carrier frequency = 0.982 MHz (alternate channel).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 400 Hz.
g. Enable AM Modulation. Enable RF carrier.
5. Adjust generator #2 RF level, VRF1, until the sinad = 20 dB.
6. Rejection (dB) = VRF1 – VRF0.
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3.3.8. Image Rejection
This test measures the image rejection for image at frequency ±186 kHz.
1. The image injection side can be positive or negative depending on the frequency of tuner. For the frequency
mentioned in this test routine, the injection side is negative (image rejection at negative 186 kHz). If the user
need to use other frequency value, they can read the image injection side from the chip and decide whether to
use positive or negative image offset (refer to "Appendix B—Reading Image Offset Side Using the Audio GUI"
on page 44).
2. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
3. Configure generator #1:
a. Set carrier frequency = 1 MHz.
b. Set AM Modulation Depth = 30%.
c. Set Source = LFGEN (internal).
d. Set LFGEN frequency = 1 kHz.
e. Set signal level VRF1 = 54 dBµV.
f.
Enable modulation.
g. Enable carrier.
4. Disable generator #3.
5. Configure generator #2:
a. Set carrier frequency = 0.814 MHz.
b. Set image level VRF2 = 82 dBµV.
c. Set AM Modulation Depth = 30%.
d. Set Source = LFGEN (internal).
e. Set LFGEN frequency = 0.4 kHz.
f.
Enable generator.
g. Enable modulation.
6. Set audio analyzer at fixed 1 kHz and read the (message) level value VAUDIO0
7. Set audio analyzer at fixed 0.4 kHz and read the (image) level value VAUDIO1
8. VAudioRelative = VAUDIO0 – VAUDIO1.
9. VRFRelative = VRF2 – VRF1.
10.Image Rejection = VAudioRelative + VRFRelative.
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3.3.9. IP3
Intermodulation distortion in the detected or decoded audio-frequency signal may be caused by non-linearity in the
radio-frequency, intermediate-frequency, and detector stages of the receiver. A good measure of intermodulation
distortion is IP3. IP3 is the theoretical RF level at which two blockers (VRF1), offset from the desired frequency by
f and 2f, and their intermodulation product.
In our test:






1.
40/80 kHz offset
f1 = 1040 kHz (blocker #1) f2 = 1080 kHz (blocker #2)
2 x f1 – f2 = 1 MHz (tuner frequency)
140/280 kHz offset
f1 = 1280 kHz (blocker #1) f2 = 1140 kHz (blocker #2)
2 x f1 – f2 = 1 MHz (tuner frequency)
The following procedure describes the 40/80 kHz offset testing:
The IP3 test requires that after configuring the tuner in standard configuration, the tuner should be set at
maximum gain. To achieve maximum gain,
a. Boot the tuner in standard configuration.
b. Turn OFF RF output of the generators.
c.
Turn OFF the Tuner AGC. The tuner AGC can be turned off using the Audio GUI.
i. In the Audio GUI, select Window  Properties menu. This launches the properties window.
ii. In properties Window Select Property Category AM:AGC Properties.
iii. In AGC Properties set AGC State Off.
2. Configure the audio analyzer:
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a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
3. Configure generator #1 (For the carrier signal):
a. Set carrier frequency = 1000 kHz.
b. Set RF level = 54 dBµV (VRF_message).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN (internal).
f.
Set LFGEN frequency = 1 kHz.
g. Enable modulation. Enable carrier.
4. Configure generator #2 (For the blocker#1 signal):
a. Set carrier frequency = 1040 kHz.
b. Set RF level = 92 dBµV (VRF_blocker).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN.
f.
Set LFGEN frequency = 400 Hz.
g. Enable modulation. Enable carrier.
5. Configure generator #3 (For the blocker#2 signal):
a. Set carrier frequency = 1080 kHz.
b. Set RF level = 92 dBµV (VRF_blocker).
c. Set AM Modulation Depth = 30%.
d. Set Source = LFGEN (internal).
e. Set LFGEN frequency = 400 Hz.
6. Read the message level rms value (due to carrier at 1kHz) displayed in the analyzer (Vrms_message (dBV))
7. Turn the Generator #1 modulation OFF
8. Setup Analyzer at fixed frequency of 400 Hz (blocker)
9. Read the blocker level rms value (due to blocker at 400 Hz) displayed in the analyzer (Vrms_blocker (dBV))
10.Calculate IP3
a. RelativeLevel = (Vrms_message – Vrms_blocker)
b. MessageInputLevel = VRF_message + 20.0 x Math.Log10(0.3)
c. BlkMessageInputLevel = MessageInputLevel – RelativeLevel
d. IP3 = VRF_blocker + ((VRF_blocker – BlkMessageInputLevel)/2)
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3.3.10. IP2
The following procedure describes the IP2 testing
1. The IP3 test requires that after configuring the tuner in standard configuration, the tuner should be set at
maximum gain. Follow the same procedure as IP3 test above to set the tuner to maximum gain.
2. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Bandwidth = BP 3%.
c. Set Units = dBV.
d. Set Frequency Mode = FIX: 1 kHz.
3. Configure generator #1 (For the carrier signal):
a. Set carrier frequency = 1000 kHz.
b. Set RF level = 48 dBµV (VRF_message).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN.
f.
Set LFGEN frequency = 1 kHz.
g. Set Filter OFF
h. Enable modulation. Enable carrier.
4. Configure generator #2 (For the blocker#1 signal):
a. Set carrier frequency = 400 kHz.
b. Set RF level = 96 dBµV (VRF_blocker).
c. Select AM Modulation.
d. Set AM Modulation Depth = 30%.
e. Set Source = LFGEN.
f.
Set LFGEN frequency = 400 Hz.
g. Enable modulation. Enable carrier.
5. Configure generator #3 (For the blocker#2 signal):
a. Set carrier frequency = 600 kHz.
b. Set RF level = 96 dBµV (VRF_blocker).
c. Set AM Modulation Depth = 30%.
d. Set Source = LFGEN.
e. Set LFGEN frequency
f.
Set LFGEN frequency = 400 Hz.
6. Read the message level rms value (due to carrier at 1 kHz) displayed in the analyzer (Vrms_message (dBV)).
7. Turn the Generator #1 modulation OFF.
8. Setup Analyzer at fixed frequency of 400 Hz (blocker).
9. Read the blocker level rms value (due to blocker at 400 Hz) displayed in the analyzer (Vrms_blocker (dBV)).
10.Calculate IP2.
a. RelativeLevel = (Vrms_message - Vrms_blocker)
b. IP2 = 2 x VRF_blocker + RelativeLevel – VRF_message
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4. RDS Testing
This section covers testing the RDS test procedure for the Si477x receiver. Table 3 provides a summary of tests
and equipment.
Table 3. RDS Test Equipment
Test
RDS Sensitivity
RDS BLER Test
RDS Sync Persistence Test
RDS Sync Stability Test
RDS Sync Time Test
Equipment
Rohde & Schwarz SMB + Stereo/RDS Signal Generator #1
USB Power Supply*
*Note: You can power up the EVB through two Agilent E3646A Power Supplies.
4.1. RDS Tuner Configuration
1. Input Frequency: 98 MHz.
2. Enable RDS (setProperty(0x4002, 0xFFF1).
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4.2. RDS Testing Procedures
The following procedures describe RDS measurement procedure. The Audio GUI is used during the RDS tests to
make the measurements. For instruction about measurements using RDS window of the Audio GUI refer to
"Appendix C—Reading RDS information using the Audio GUI" on page 45.
4.2.1. RDS Sensitivity
RDS sensitivity is the minimum RF level required to produce an audio output with a specified block error rate
(BLER), 5%. BLER is a ratio of the number of data blocks received with at least one un-correctable bit to the
number of blocks received.
1. Configure generator #1:
a. Set carrier frequency = 97.9 MHz.
b. Set initial RF level to 5 dBuV (this level is changed later to find the sensitivity level).
c. Select stereo modulation.
i. Set FM Deviation = 22.5 kHz.
ii. Set Stereo Mode = Left Only
iii. Set Source = LFGEN (internal).
iv. Set LFGEN frequency = 1 kHz.
v. Set Pre-emphasis = OFF.
vi. Set Pilot = ON.
vii. Set Pilot Deviation = 6.75 kHz.
viii. Set RDS = ON.
ix. Set RDS Deviation = 2 kHz.
x. RDS State = ON
xi. Set RDS Data Set = 1.
xii. Set Traffic Announcement = OFF.
xiii. Set Traffic Program = OFF.
xiv. ARI State = Off
d. Enable modulation. Enable carrier.
2. Adjust generator #1 RF level, VRF0. Using the Audio GUI measure BLER (by reading the Error Rate from GUI)
until BLER = 5%. After changing the RF level each time, press the Reset button in the RDS window and wait for
25 seconds before reading the Error Rate (BLER) from the GUI.
3. Sensitivity (dBµV) = VRF0.
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4.2.2. RDS BLER
BLER stands for block error rate, which is a ratio of number of data blocks received with at least one un-correctable
bit to the number of blocks received. This test is often used to test the RDS Sensitivity (BLER <5%) specification
during production.
1. Configure generator #1:
a. Set carrier frequency = 98 MHz.
b. Set RF level = 20 dBuV.
c. Select stereo modulation
i. Set FM Deviation = 22.5 kHz.
ii. Set Stereo Mode = Left Only
iii. Set Source = LFGEN (internal).
iv. Set LFGEN frequency = 1 kHz.
v. Set Pre-emphasis = OFF.
vi. Set Pilot = ON.
vii. Set Pilot Deviation = 6.75 kHz.
viii. Set RDS = ON.
ix. Set RDS Deviation = 2 kHz.
x. RDS State = ON
xi. Set RDS Data Set = 1.
xii. Set Traffic Announcement = OFF.
xiii. Set Traffic Program = OFF.
xiv. ARI State = OFF
d. Enable modulation. Enable carrier.
2. Using the Audio GUI measure BLER. Wait for 25 seconds before reading the Error Rate (BLER) from the GUI
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4.2.3. RDS Sync Persistence/Sync Stability Test
RDS Sync is influenced by the signal quality and strength. Once the RDS is synchronized, the FM tuner has the
ability to maintain its synchronization even with high BLER and fading signal strength. This test measures the
ability to maintain RDS Sync in degrading signal conditions.
1. Configure generator #1:
a. Set carrier frequency = 98 MHz.
b. Set RF level = 5 dBuV.
c. Select stereo modulation.
i. Set FM Deviation = 22.5 kHz.
ii. Set L=R.
iii. Set Source = LFGEN (internal).
iv. Set LFGEN frequency = 1 kHz.
v. Set Pre-emphasis = 75 µs.
vi. Set Pilot = ON.
vii. Set Pilot Deviation = 6.75 kHz.
viii. Set RDS = ON.
ix. Set RDS Deviation = 2 kHz.
x. Set RDS Data Set = 1.
xi. Set Traffic Announcement = OFF.
xii. Set Traffic Program = OFF.
xiii. ARI State = OFF
d. Enable modulation. Enable carrier.
2. Using the Audio GUI, observe the RDS button turning from red to green (the button turns green when sync is
established) by Increasing the Generator#1 RF level. Register the RF level at which the RDS button turns and
stays green for at least 10 seconds. This level is the RDS Sync Stability Level.
3. Increase the Generator #1 RF level by 5 dBµV from the Sync Stability Level. Now decrease the RF level and
observe the RDS button in the GUI to turn from green to red (Sync lost) and stay red for at least 10 seconds.
The RF level at which the sync is lost is the RDS Sync Stability Level.
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4.2.4. RDS Sync Time Test
This test measures the time required to establish the RDS Sync.
1. Configure generator #1:
a. Set carrier frequency = 98 MHz.
b. Set RF level = 20 dBµV.
c. Select stereo modulation
i. Set FM Deviation = 22.5 kHz.
ii. Set Stereo Mode = Left Only.
iii. Set Source = LFGEN (internal).
iv. Set LFGEN frequency = 1 kHz.
v. Set Pre-emphasis = OFF.
vi. Set Pilot = ON.
vii. Set Pilot Deviation = 6.75 kHz.
viii. Set RDS = ON.
ix. Set RDS Deviation = 2 kHz.
x. RDS State = ON
xi. Set RDS Data Set = 1.
xii. Set Traffic Announcement = OFF.
xiii. Set Traffic Program = OFF.
xiv. ARI State = OFF
d. Enable modulation. Enable carrier.
2. Using the Audio GUI make sure that sync is established (RDS button turns green). Wait for at least 10 seconds
after the sync is established. Measure the sync time from GUI display (RDS Sync … ms text box)
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5. MPX Test Procedures
This section covers testing the tuner’s MPX output performance for suitability in receiving VICS service. This
testing will use the same configuration testing FM performance. MPX is output via the left analog audio output DAC
at the LOUT pin and can be accessed via the LOUT at the audio (just as left channel audio is access in FM testing).
Note: Take care not to use the ROUT output for MPX testing.
Table 4. MPX Tuner Test Equipment
Test
Sensitivity
Audio Output Voltage
Audio SNR
Frequency Response
Equipment
Rohde & Schwarz UPV Audio Analyzer
Rohde & Schwarz SMB + Stereo/RDS Signal Generator #1
USB Power Supply*
*Note: You can power up the EVB through two Agilent E3646A Power Supplies.
5.1. MPX Tuner Testing Calibration
During MPX testing power combiner and cable losses must be calibrated and factored into each measurement.
The calibration is performed by setting the Generator#1 at 83 MHz and 0 dBm and measuring the RF power at the
DUT. The calibration factor is either programmed as an offset to the generator or manually compensated during
measurement. All the levels specified in this document are the levels that should be set at the DUT.
5.2. MPX Tuner Configuration
The default power up configurations for MPX tuner can be used for the tests. During initialization, the user should
select the Output Mode of the Audio GUI as MPX Audio. This Configure LOUT for MPX and disable ROUT.
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5.3. MPX Tuner Test Procedure
5.3.1. MPX Output Voltage Level
Output voltage level is measured as an RMS value with a modulation frequency of 76 kHz (VICS service
frequency) under the below conditions.
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Analyzer Bandwidth to 80 kHz.
c. Set Filter Bandwidth = BP 3%.
d. Set Units = VRMS.
e. Set Frequency Mode = FIX: 76 kHz.
2. Configure generator #1:
a. Set carrier frequency = 83.0 MHz. Set RF level = 65 dBµV. Select FM Modulation.
b. Set FM Deviation = 3 kHz. Set Source = LFGEN (internal).
c. Set LFGEN frequency = 76 kHz.
3. Enable modulation. Enable carrier.
4. Audio level (VRMS) = measured VAUDIO0 from Audio Analyzer
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5.3.2. MPX Audio Frequency Response
MPX audio frequency response is measured as a dB value in relation to a 1 kHz test tone. The measurements may
vary, but typically the difference is measured at 76 kHz (the VICS tone) at a minimum. Silicon Labs measures the
difference at 65, 76, and 85 kHz. The measurement below is repeated for each of these frequencies and compared
to 1 kHz.
1. Configure the audio analyzer:
a. Set Function = RMS Select.
b. Set Analyzer Bandwidth to 250kHz.
c. Set Filter Bandwidth = BP 3%.
d. Set Units = dBV.
e. Set Frequency Mode = FIX: 1 kHz.
2. Configure generator #1:
a. Set carrier frequency = 83.0 MHz. Set RF level = 65 dBµV. Select FM Modulation.
b. Set FM Deviation = 7.5 kHz. Set Source = LFGEN (internal).
c. Set LFGEN frequency = 1 kHz.
3. Enable modulation. Enable carrier.
4. Audio level (dBV) is displayed. Note the output at 1kHz, then repeat the above procedure by setting the audio
analyzer Frequency Mode to measure a FIX frequency and the generator’s LFGEN frequency tone for:
a. 65 kHz
b. 76 kHz
c. 85 kHz
5. Compare each measurement to the audio level for 1kHz to determine the MPX audio frequency response.
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5.3.3. MPX SNR
The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio frequency output voltage
due to the signal to that due to random noise.
1. Configure the audio analyzer:
a. Set Function = THD+N/SINAD.
b. Set Measurement Mode = NOISE.
c. Set Units = dB.
d. Fundamental = 76 kHz fixed.
e. Set Frequency Limit Low = 30 Hz.
f.
Set Frequency Limit Upper = 80000 Hz.
2. Configure generator #1:
a. Set carrier frequency = 83.0 MHz. Set RF level = 65 dBµV.
b. Select FM Modulation.
c. Set FM Deviation = 3 kHz. Set source = LFGEN (internal).
d. Set LFGEN frequency = 76 kHz.
e. Enable modulation. Enable carrier.
3. Disable generator #2.
4. Record SNR (dB) = – Noise (dB) (from analyzer).
5.3.4. MPX Sensitivity
MPX Sensitivity of a receiver is a measure of its ability to receive weak signals and produce an MPX output at the
76 kHz VICS frequency of usable magnitude and acceptable quality. For the purposes of our testing, sensitivity is
the minimum RF level required to produce an audio output with a specified signal-to-noise ratio of 5 dB.
1. Configure the audio analyzer:
a. Function: THD+N/SINAD.
b. Measurement Mode = NOISE.
c. Fundamental = 76 kHz fixed.
d. Filter = OFF.
e. Frequency Limit Low = 30 Hz.
f.
Frequency Limit High = 80000 Hz.
g. Set Unit = dB.
2. Configure generator #1:
a. Set carrier frequency = 83.0 MHz.
b. Select FM Modulation.
c. Set FM Deviation = 3 kHz.
d. Set Source = LFGEN (Internal). Set LFGEN frequency = 76 kHz.
e. Enable modulation. Enable carrier.
3. Disable generator #2.
4. Adjust generator #1 RF level, VRF0, until audio analyzer NOISE = –5 dB. Sensitivity (dBµV) = VRF0.
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APPENDIX A—SETTING PROPERTIES USING THE AUDIO GUI
The properties can be set using Audio GUI in two different ways: using property window or register map. To change
properties using the property window:
1. Launch Audio GUI and initialize the tuner.
2. Launch the properties window from menu Window  Properties.
3. In the property Category, user can select individual categories or FM:All (AM:All, WB:All, etc).
4. Select the desired category and property and change the value.
5. Observe the Property address and changed property value (In the example below Blend Fast Stereo
Separation was changed to 40 dB that changes property 0x3501 to 0x2800).
Alternately the user can change the property values using the register map:
1. Select from the menu Window  Register Map.
2. Select CMD Set_Property (0x13).
3. ARG2 is the 8MSBs and ARG3 is the 8LSBs of the property address (e.g. property address 0x3501, ARG2 =
0x35, ARG3 = 0x01). ARG4 is the 8MSBs and ARG5 is the 8LSBs of the property value (e.g., property value
0x2800, ARG4 = 0x28, ARG5 = 0x00).
4. After setting the values in the window, press Send Command.
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APPENDIX B—READING IMAGE OFFSET SIDE USING THE AUDIO GUI
The rsq_status can be read using the Audio GUI to determine the status and values of different chip parameters.
The following example shows How to read the injection side for AM Image Rejection Test.
1. Initialize the chip in AM mode.
2. From Tools menu, select Register Map. This will launch the register map window.
3. In CMD drop down box, select Am_Rsq_Status (0x42).
4. Press the button Send Command.
5. Mask RESP2 with 0x04. (In the example, 0x10 would be masked with 0x04, resulting in 0x00). If the resulting
value is 0, the image offset is negative. Otherwise, it is positive.
Initialize chip in FM mode and follow the same procedure to determine FM Image Offset Side.
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APPENDIX C—READING RDS INFORMATION USING THE AUDIO GUI
1. Launch audio GUI and tune the desired Frequency
2. From the Window Menu, select RDS Receive Data. This launches the RDS window
3. In the RDS window, the RDS button turns green when RDS sync is established. Wait for at least 10 seconds
after sync turns green to make sure that the sync is stable.
4. The Error Rate and Syc Time are displayed in the window.
5. After changing any RF input level to the RDS receiver, please press the Reset button to re-acquire data.
6. Wait for at least 25 sec before reading the Error Rate. There are two Error Rates displayed, After Tune and After
Sync. The two values should show same value after waiting for 25 seconds.
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Disclaimer
Silicon Laboratories intends to provide customers with the latest, accurate, and in-depth documentation of all peripherals and modules available for system and software implementers
using or intending to use the Silicon Laboratories products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific
device, and "Typical" parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. Silicon Laboratories
reserves the right to make changes without further notice and limitation to product information, specifications, and descriptions herein, and does not give warranties as to the accuracy
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