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Analog Trends

Observations on changes affecting semiconductor needs in personal appliances

—by Madhu Rayabhari
Director, Strategic Marketing
Fairchild Semiconductor

As end-systems evolve in product design, boundaries between traditional classifications are rapidly eroding. Integrated cell-phone/PDAs, PDAs with GPS capabilities, notebook PC with integrated web-cameras, and set-top boxes with integrated router and hub functions for inter-net access, are common examples of this trend to incorporate elements of communications, computing and consumer/entertainment segments. The impact on the underlying electronics are found in several significant trends in the analog world:

• sub-system and system level integration
• advanced power management
• digital techniques & programmable analog

These macro trends reflect solutions to evolving end-system design needs.

On-chip integration at the sub-system level, and in many cases at the system level, is key to satisfying constraints placed by ever-shrinking form factors and functionality upgrades. High levels of integration need fairly advanced implementations of power and system management to handle the higher currents and decreasing system voltages in smaller packages, which then create issues such as thermal management. Battery power is increasingly critical as more sys-tems move to portable formats. The ability to monitor system performance, drive up system efficiencies and maximize battery life, while providing rapid charging for various battery chemistries, also affects power management. In fact, advanced power management is becom-ing a major factor in successful system design.

Various digital blocks such as microcontrollers, DSPs and state machines are finding new homes in traditional analog ICs. Systems are requiring increasingly higher levels of sophistica-tion in control and manipulation of analog signals, as well as software control for various analog blocks and advanced communication protocols to transfer data and control informa-tion. Examples such as the Smart-Battery System in personal computers and the Controller Area Network [CAN] protocol in automotive applications illustrate this trend [One chip manufacturer is developing a single chipset for automotive applications that will pack a proc-essor, graphics-display controller, SDRAM controller and dual CAN channels. —DFX]. Data conversion blocks (A/D and D/A), and low power implementations of each of these digital and mixed-signal blocks, affect successful system implementations.

Most real world inputs & outputs, such as light, sound and temperature, are analog, while information processing is mainly done digitally. Analog signal processing blocks interface between the digital and analog portions of a system. Using elements such as EEPROM, Flash or SRAM Cells, various analog elements are available that provide field-alterable/software-alterable characteristics. Examples include amplifiers with programmable gain, supervisory ICs with programmable thresholds and programmable references. More complex examples growing in popularity include devices such as Field Programmable Analog Array (FPAA) and the Totally Reconfigurable Analog Circuit (TRAC).