AN569 Si4831/35/36/20/24/25-DEMO BOARD TEST PROCEDURE 1. Introduction This document describes the test procedures for the Si4831/35/36/20/24/25-DEMO AM/FM/SW tuner board. 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 FM, AM, and SW tests for the Si4831/20 and Si4835/36/24/25 receiver. The Si4831/35/36/20/24/25-DEMO board provides a platform to test and operate the Si4831/35/36/20/24/25 tuner. Refer to the Si4831/35/36/20/24/25 DEMO Board User s Guide for the operation details of the demo board. 2. FM Tuner Testing Setup 2.1. FM Common Setup FM tuner standard configuration: Tune exactly to 98.0 MHz see the Si4831/35/36/20/24/25 DEMO Board User s Guide for details. Set volume to maximum unless otherwise specified. Ensure cable length between the generator and antenna input is as short as possible. - *+, ( ) ( ) *+, Figure 1. FM Tuner Setup with One Generator Rev. 0.3 2/13 Copyright 2013 by Silicon Laboratories AN569 AN569 %& *+, - ( ) ( ) *+, Figure 2. FM Tuner Setup with Two Generators FM tuner test equipment lists: Rohde & Schwarz UPL Audio Analyzer. Rohde &Schwarz SML01 Signal Generator Mini-Circuits Power Combiner 2.2. FM Tuner Testing Considerations Several issues must be considered to make accurate measurements. First, the power combiner and cable losses must be calibrated and factored into each measurement. The loss for the Mini-Circuit power combiner is approximately 6 dB. Second, most signal generators display the voltage generated at the input of the device under test (DUT), assuming an input resistance of 50 . For example, if the signal generator displays VL = 1 V (0 dB V), the generator source voltage VS is 2 V (6 dB V). The load voltage VL is generated from the source voltage VS by the voltage divider created by the 50 generator source resistance RS and the 50 load resistance RL. This distinction is important only for sensitivity, and IP3, which are specified in V EMF*, where EMF refers to the source voltage VS. Measurements such as AM suppression, selectivity, and spurious response are relative and may be referenced using VS or VL. To summarize, the generator displays the voltage at the input of the DUT. Input impedance for the Si4831/35/36/20/24/25 FM tuner is high, so to convert the value displayed on the signal generator to EMF, double the voltage (add 6 dB). *Note: EMF = Electro Motive Force 2 Rev. 0.3