EXPERIMENTS WITH IEEE 1149.4 KLIC TEST CHIP A Case Study

The paper presents some results of the experiments with IEEE 1149.4 KLIC Test Chip in the area of active RC filters implemented in thick-film hybrid technology. The influence of analog boundary modules (ABMs) on circuit performance is analysed in the case study of active RC notch filter. INTRODUCTION In this paper we present some results of the experiments with IEEE 1149.4 KLIC Test Chip in the area of active RC filters implemented in thick-film hybrid technology. The thick-film hybrid process is a technology between the monolithic integrated and printed circuit technologies. It integrates the conductive and insulating layers with thick-film resistors on a ceramic substrate. Discrete elements (capacitors, diodes, transistors, integrated circuits, etc.) are soldered, bonded or glued onto the substrate. An advantage of active RC filters implemented in thick-film hybrid technology is the ability of active adjusting the characteristics (frequencies of poles and zeros, quality factor) by laser trimming of selected resistors. The required performance of such circuits is often specified within narrow tolerance ranges. The goal of our case study was to analyse the influence of IEEE 1149.4 ABMs on the circuit performance. For a rough estimation we first modeled the ABM module by a simple RC circuit and simulated the operation of the selected hybrid circuit with and without ABM modules. Next, real ABM modules were inserted and the circuit performance was analysed. SELECTED CIRCUIT For the case study we have chosen the active RC notch filter (as a part of a thick-film hybrid circuit for a telecommunication application). The circuit under consideration is shown in the next figure. (The values of its components have been measured after adjusting the filter characteristics.) Figure 1 WLOG we consider the simplified notch filter shown in Figure 2. In order to analyse the impact of circuit parameters on its performance we first express the transfer function .