HICUM
High Speed Bipolar Model

A Model Facing High-Speed Requirements

The major effects taken into account by HICUM are :

• High-current effects
   
• Distributed high-frequency model for the external base-collector region
   
• Emitter periphery injection and associated charge storage
   
• Emitter current crowding
   
• Two- and three-dimensional collector current spreading
   
• Parasitic (bias dependent) capacitances between base-emitter and base-collector terminals
   
• Vertical non-quasi-static effects for transfer current and minority charge
   
• Temperature dependence and self-heating
   
• Weak avalanche breakdown at the base-collector junction
   
• Tunneling in the base-emitter junction
   
• Parasitic substrate transistor
   
• Bandgap differences, occuring in HBTs
   
• Lateral scalability
  

DC characteristic Ic=f(Vce)

Transconductance gm=dIc/dVbe at variable bias

Cutoff frequency vs. Bias conditions

Advanced Applications

HICUM provides the designers’ community with a powerful model, dedicated to high-speed applications. This model has been developed by Prof. M. Schroter at Ruhr-University, Germany.
The operating region of the transistor has been developed with an emphasis on high current densities. Expressions used in the model include the effects encountered in short transistors, where emitter length is close to width.

Simucad Implementation

• HICUM is compatible with VZERO option in order to achieve great simulation speed performance
   
• 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
   
• HICUM model is part of the SmartLib™ product-independent model library. It can be accessed within SmartSpice™ as level 6
   
• SmartSpice implementation has been validated using the reference simulator, Device, developped by the creator of the model
  

Rev. 101807_03