AN2657 Datasheet, PDF (1/18 Pages) STMicroelectronics – An innovative verilog model for predicting

AN2657
Application note
An innovative verilog model for predicting
LDMOS DC, small and large signal behavior
Introduction
To reduce the design cycle time and cost for wireless applications it is useful to have models
that can help RF Engineers predict and simulate the behavior of RF power transistors.
Recently, STMicroelectronics has been strongly focused on developing new models for RF
LDMOS power transistors.
The model introduced here is simple in concept, and describes with good approximation
DC, small signal S-parameter and large signal behavior, and could be a starting point for
designers in developing their new applications. This model has been implemented in Agilent
Advanced Design System, in verilog Language, and includes the parasitic elements of the
package, as well as a thermal node which takes self heating effects into account.
In this applicatio note we will briefly describe how to extract the model parameters for the
PD54003L-E device, which is a 3 W - 7.2 V - 500 MHz LDMOS housed in a PowerFLAT
plastic package (5 x 5 mm). As an internally unmatched device, the PD54003L-E can be
used in various portable applications over HF, VHF and UHF frequency bands. At the end of
this note we will validate this new model using ST's DB-54003L-175 demoboard, especially
designed for 2-way portable radio applications using PD54003L-E over the 135-175 MHz
frequency band.
Thanks to their cost effectiveness and high performance, LDMOS devices are widely used
in radio frequency applications, ranging from digital communication infrastructures (cellular
base stations) to low cost portable radios (private mobile radios) commonly known as
walkie-talkies.
November 2007
Rev 1
1/18
www.st.com