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Designers now require a design methology that can supply a unified approach to system and circuit design. Verilog-AMS is one solution that gets the job done.
Portable power integrated circuits commonly have been placed into two categories: analog dominated products such as battery chargers or buck/boost converters, and digital dominated products such as battery gas gauges. Dividing products this way allowed designers to stay either in the analog or digital world without requiring the ability for mixed-signal IC design flow.
Product demand has had its way, though, and now IC development groups must look for a new design and verification flow that can handle complex mixed signal IC designs to meet the requirement for complete SoC for power management applications with extensive digital control. And, not only has product complexity increased, but so has the pressure to reduce the time to market. Therefore, a big part of the new design flow is to reduce overall project cycle time.
Two methods reduce project cycle time for complex SoCs. First, the design flow uses a verification tool to speed fast mixed signal top-level simulation cycles with acceptable accuracy for analog circuits. secondly, the design flow offers a better way to hand off the product from the system definition to the IC design team.
Because software platforms differ, there is no direct software interface between systems and IC design other than the device specification. When both system level designers and 1C level designers use the same software tools, system defined test benches or system components can be reused, and misunderstandings between systems and design groups are reduced.
Portable Power Applications
Today's portable power management ICs integrate more and more features to be competitive. For the discussion herein, a battery charger IC for notebook computers is referenced, but the design methology applies to any number of circuits in any number of industries.
The battery charger IC may integrate a communications interface for a microcontroller, power path management and various functions for charge control, as well as a DC/DC converter to charge the battery. An example of this type of charger is shown in Figure 1.
Achieving adequate top-level simulation coverage of these highly integrated power management ICs has been an elusive, if not unattainable, goal for designers. For...