Nowadays a system level estimation method of power consumption for heterogeneous systems is a major concern. In this article, we introduce an empirical method for power consumption modeling of analog components at system level. The principal step of this method uses neural networks to approximate the mathematical curve of the power consumption as a function of the inputs, supply voltage and ambient temperature of an analog component. For an amplifier, we found an average error of 4.72% between our high level estimation and PSPICE power consumption results. This novel method is suitable for IP-based design and has three key features. Firstly, the method provides an online estimation of the instantaneous power consumption of analog blocks. Secondly, the method is generic as it can be applied to any analog component in any modeling and simulation environment. Thirdly, the method is suitable for the total (analog and digital) power consumption estimation of a heterogeneous system.