高頻寬切換電容式低通濾波器及內建自我測試電路

Abstract

隨著近幾年積體電路製程技術的進步，我們需要更快速及更複雜的測試設備來達到測試的規格及功能。有一種簡化測試設備的創新方法，就是將測試功能搬到晶片內部，而這種方法就叫作內建自我測試。如何在有限的面積及電源消耗增加之下來達到內建自我測試的功能，是現今混合信號測試設計者最重要的一項課題。 在本論文中，我們完成了一個全差動、取樣頻率140 MHz、轉角頻率10 MHz、切換電容式四階低通濾波器用來當作待測電路；此濾波器包括了兩個串接的biquad濾波器。除此之外，我們利用三角波各部份所佔的機率這樣一個觀念來實現我們切換電容式濾波器的內建自我測試電路。我們的內建自我測試電路包括了一個29.2 KHz三角波振盪器用來當作測試波形產生器、一個雙端轉單端電路及一個雙重比較器用來作為輸出響應分析器。利用這樣一個方法，我們可以由測試結果得知每一個biquad濾波器所擁有的增益誤差及偏移誤差。

As IC fabrication technology advances in recent years, faster and more complex test equipments are required to achieve test specifications and test functions. An innovative method to simplify the test equipment is to move test functions onto the chip itself, which is called Built-In-Self-Test (BIST). How to achieve on-chip test function with limited area and power overhead is the main issue for mixed-signal testing designers. In this thesis, we accomplish a fully-differential, 140 MHz sampling frequency, 10 MHz corner frequency, switched-capacitor 4th-order low-pass filter to be the core circuit, which consists of two cascading biquad filters. Besides, we use the concept about probabilities of a triangular-wave to implement BIST circuits for the SC filter. In our BIST circuit, it consists of a 29.2 KHz triangular oscillator taken as test-waveform-generator, a differential-to-single-ended circuit and a dual-comparator taken as output-response-analyzer. According to this approach, we can obtain the information on gain error and offset error of each biquad filters from test results.