|
Switching your focus
|
19/01/2006
|
| |
Ultra portable designs have driven the need for enhanced analogue switch products. Greater integration and improvements in process technology have brought a shift in design methods. Meanwhile, designs increasingly use different voltage rails to power and control the analogue chipset surrounding core processors and asics.
To solve this problem, Fairchild has changed how it designs its analogue switches and has begun to offer modified versions of existing products. These new analogue switches have an expanded control input range, yet maintain low current consumption and rail to rail signalling.
Ultra portable products, such as mobile phones, PDAs and MP3 players, use analogue switches in a variety of applications – from USB port sharing and isolation to audio switching. After choosing a switch based on configuration and application specific requirements, there are several key specifications that all designers look for, regardless of application.
Ultra portables rely on a battery, so power consumption is therefore a major factor in the selection of an analogue switch. In most ultra portables, there are multiple supply rails and designers will use a power management ic to detect which supplies are present. The ic will then decide whether to operate directly from the battery or from a regulated supply. Depending on the choice made, the supply voltage could range from 2.7 to 3.6V (in the case of a regulated supply from the wall) or 4.3V Vcc when powered from a fully charged battery.
|
| |
Author
Travis Williams
|
| |
| |
|
| Email this article |
| |
|
|
|
|