Analog memory unit

Abstract

An analog memory unit that can be implemented, at least in part, on an application specific integrated circuit (ASIC), utilizes at least the ASIC arithmetic logic unit (ALU) to enhance performance and to generate and store an accurate measure of power line thermal status. The memory unit includes an analog-to-digital (A/D) converter for converting an input analog signal from a parallel R-C circuit to a digital signal and a scaler for scaling the digital signal from the A/D converter to within a range acceptable for further processing. The memory unit also includes an arithmetic logic unit (ALU) which receives input signals from the scaler and from a digital thermal memory. The input signal supplied to the ALU from the digital thermal memory is a four bit (digital) value proportional to the measured actual thermal status of the subject power line. The output of the ALU is connected to the input of latches which latch, or store, the digital signal produced by the ALU. The ALU output signal is representative of the difference between charge on the R-C circuit and the most recently measured actual thermal status of the power line. The latches are connected to a digital-to-analog converter which has its output connected to the input of the A/D converter and to the R-C circuit.