An Introduction to Scan Test for Test Engineers

For any modern chip design with a considerably large portion of logic, design for test (DFT) and in particular implementing scan test are mandatory parts of the design process that helps to reduce the complexity of testing sequential circuits. The basic concept of a scan test is to connect memory elements like flipflops or latches forming chains, so that shifting through scan chains allows to control and observe the states of the DUT.
Since scan vectors are based on regular and uniform structures, basic knowledge about scan designs, scan test modes and targeted fault models helps to interpret scan vectors. Therefore, in this paper a basic introduction to scan test is given, so that a test engineer who debugs scan test on an ATE can be more efficient in a first level of fault analysis - beyond just being able to do logging of failing pins and cycles.

Introduction to FM-Stereo-RDS Modulation

Frequency modulation (FM) has a long history of its application and is widely used in radio broadcast. To transmit stereo music, FM is enhanced by stereo multiplexing which carries both L and R audio channel content. With the digital age, Radio Data System (RDS) enables FM to carry text information such as traffic, weather, and radio station information which can be displayed on the end-user’s device interface. Currently, growing number of mobile phones and consumer mobile devices will have an integrated FM receiver feature. The FM transmitter feature is also becoming popular for allowing users to transmit audio content from their mobile devices through their car radio. To make sure the FM-related functions work well, the FM mono, FM stereo, and FM RDS functions need to be tested in production. In this paper, we will discuss FM theory, FM stereo multiplexing and the RDS mechanism. The FM demodulation in V93000 will also be briefly introduced.

Parallel RF Wafer Sort Production Testing

This paper will discuss the measurement challenges and considerations for known good die testing of an RF SOC (system on chip) device. It will explore the challenges of setting up the multi-site wafer probe card and assembly. It will then discuss factors taken into account when selecting a probe station, RF wafer probe card, and ATE (automatic test equipment) test system. Challenges of testing RF performance on-wafer are described.

Solving MIPI D-PHY Receiver Test Challenges

MIPI stands for the "Mobile Industry Processor Interface", which provides a flexible, low-cost, high-speed interface solution for communication links between components inside a mobile device. While the MIPI D-PHY specification enables significant extension flexibility for various advanced applications, it also creates new test challenges for device manufacturers. In this paper we will discuss in detail how three-level signals required for MIPI D-PHY testing can be generated on all standard V93000 Pin Scale digital cards.

Mathematical Derivation of the C++ Routine Used to Initialize Arrays with Sinusoidal Waveforms

Since the early 1970s, digital signal processing has become common place. Yet digital creation of waveforms is not often described. This article describes the mathematical process one uses to create single tones, multi-tones, complex multi-tones and IF signals.

An Introduction to WiMax

There are several needs that have to be met simultaneously for successful demodulation analysis. There is creating the ideal waveform, analyzing and understanding the waveform, applying this waveform to the test equipment, acquiring the signal through instrumentation, and finally analyzing the signals to measure the DUT’s performance. Before any of these steps can begin, it is important for users to understand the basics of WiMax modulation, and its essential components.

Multi-Site Efficiency and Throughput

In the ATE (Automated Test Equipment) industry there are two key concepts used to measure the efficiency of making measurements. These concepts are multi-site efficiency and throughput. It is critical that both of these be used together so that all corner cases can be explored. These two concepts and their impact will be explored in this article.

Choosing the Dielectric Material for a V93000 DUT Loadboard

This application note discusses the influence of the dielectric material choice on the performance of DUT loadboards for high-speed digital applications. The objective is to show that changing from a low loss material to an even lower loss material provides little performance increase due to the fact that typical V93000 DUT loadboards have long trace lengths where the skin effect loss dominates the DUT loadboard signal trace loss.

Centering Pulse Waveform

In a settling time measurement, rise/fall time calculation, and tests known as template fitting test, samplers are used to record waveforms. The test signal waveform in such applications is usually a clock signal with 50% duty ratio. You may want to shift this waveform in the unit test period window to a position so you can analyze and parameterize it. This technical note describes how to shift ("center") your waveform to any desired phase.

HVM Receiver Noise Figure Measurements

In the last few years, low-noise amplifiers (LNA) have become integrated into receiver devices that bring signals from the antenna to analog or digital baseband domains (I and Q). In doing so, it has become more commonplace to test noise figure in this RF-to-baseband configuration. There are two primary techniques used to perform noise figure measurements on these devices with automated test equipment (ATE); Y-Factor and Cold Noise (or Gain) methods. Differences between making measurements on RF-to-RF devices and RF-to-baseband devices are discussed in this article. Additionally, considerations for HVM (High-Volume Manufacturing) testing of noise figure are presented.

Application Note - Filter Test using Pseudo Swept Frequencies

Frequency response is a key test item for filters. To measure the gain-frequency response, phase-frequency response, and group delay for filters, you can use the pseudo swept frequencies method. This method incrementally changes the input signal frequency to a filter (DUT), and measures the output signal from the filter.

Method for calculating SNR for Non-integer Cycle Sine Wave

Sine waves are the most fundamental waveform used in analog tests. In the mixed-signal IC testers which use DSP (digital signal processing), they are used to calculate test parameters such as THD (total harmonic distortion), SNR (signal-to-noise ratio) and frequency characteristics with FFT (fast Fourier transform). However, if the frequency of the measured sine wave is slightly different from expected frequency, and the number of cycles of the captured waveform ceases to be an integer, then FFT processing will cause leakage and the measurement accuracy will decline. Read entire application note.