Modella
Lateral PNP Bipolar Model

Dedicated Lateral PNP Model

The MODEL-LAteral model developed by Philips N.V. provides an accurate model dedicated to lateral PNP devices.

This model is based on a totally new approach, accounting for the complex bi-dimensional structure of lateral transistors. Modella allows the simulation of lateral devices using real physically based parameters, instead of using less accurate empirically-modified models, such as Gummel-Poon.
With Modella, lateral PNP bipolars do not lack an accurate model anymore.

Influence of excess-phase on current gain

Ic vs. Vce characteristic

Major Improvements

Modella benefits from the following improvements with regard to the older Gummel-Poon model:

• More complex resistive network, using more internal nodes
• Separation of bottom and sidewall components, describing the 2D structure of the transistor
• No nonphysical parameter (for example, current crowding is modeled, using only one parameter)
• Symmetry of the equivalent circuit, thanks to a split base resistance
• Equations derived from PNP formulations
• No iterative process used in equations, resulting in short simulation times

Physically-Based Lateral Bipolar Model

Modella accounts for the bi-dimensional structure of lateral PNP devices, modeling physical effects such as:

• Explicit modeling of inactive regions
• Excess-phase shift for current and storage charges
• Charge storage
• Temperature
• High-injection
• Built-in electric field in base region
• Bias-dependent Early effect
• Low-level non-ideal base currents
• Hard and quasi saturation
• Weak avalanche
• Current crowding and conductivity modulation of thebase resistance
• Hot carrier effects in the collector epilayer
• Split base-collector depletion capacitance
  

Simucad Implementation

• Modella is compatible with VZERO and BYPASS options in order to achieve great speed performance
• Internal warnings and diagnostics provide valuable information to help finding convergence issues
• User-friendly parameters checking; user is kept aware of every clipped parameter
• Device internal variables (currents, conductances, charges...) can easily be accessed like any other parameter
• Modella model is part of the SmartLib™ product-independent model library. It can be accessed within SmartSpice™ as level 500
  

Rev. 101807_03