Wireless Systems Design

Solutions Target Power And Display Development

A group of mixed-signal ASICs has been introduced to aid the development and proliferation of next-generation portable wireless devices. These single-chip ASICs, which number seven in total, include innovative display-lighting and analog power-management units. Targeted at OEMs, they will allow extra features to be added very quickly. As a result, OEMs can simplify product design, reduce cycle times, and get products to market faster than ever before.

The display-lighting units (LP3933 and LP3936) offer programmability and flexibility with features such as 'fun-lighting' and camera 'flash' support. They also bring unmatched levels of integration and efficiency to the table. The LP3933 is designed to provide drive, high efficiency, and fully featured display-lighting control for "clam-shell" or flip phones. Typically, such devices have a camera, one or two RGB indicator LEDs, a main display, and sub/CallerID display.

The LP3933 is priced at $1.35 each in quantities of 500,000. Its sibling, the LP3936, has all of the same capabilities but with only one RGB-indicator LED-driver function. It is priced at $1.20 each in 500,000 quantities.

The programmable analog power-management units (LP3935, LP3938, LP3941, LP3945, and LP3946) include fully independent and programmable Li-Ion and NiMH battery-charging functions. They also flaunt high-efficiency linear regulators, system startup and control, serial interfaces, and display-LED drivers. All of these features are integrated in one compact, thermally efficient leadless-leadframe (LLP) package.

Specifically, the LP3935 integrates seven programmable, low-dropout linear regulators. By providing low noise, on/off control, low current consumption, and excellent power-supply rejection, it ensures minimal interference between each supply. It is priced at $1.75 each in quantities of 500,000.

The LP3938 is an upgraded version of the LP3935. It boasts an improved charger, one extra linear regulator, and a TCXO buffer. In addition, two of its regulators have an idle mode. It sells for $1.85 each in 500,000 quantities.

The LP3941 contains 11 low-dropout regulators. They are integrated with an RGB LED driver, Li-Ion/NiMH battery charger, backup battery charger, RTC-LDO, and two comparators. The comparators offer system-monitoring and control features. The LP3941 is priced at $2.05 each in quantities of 500,000.

Both the LP3945 and LP3946 are Li-Ion/NiMH chargers. They are ideal for a range of portable battery-operated equipment. The LP3945 is programmable through an I2C interface, whereas the LP3946 is pre-programmed at the factory. The LP3945 and LP3946 are priced at $1.00 and $0.90 apiece, respectively, in 500,000 quantities.

Initially, the ASIC devices will be offered in both small leadless-leadframe (LLP) and laminate chip-scale packages (CSP). A Microfil packaging option will follow shortly. This choice will provide customers with size reductions that will be from 4X to 7X smaller than conventional packaging. This option is expected to be available in the summer of 2003.

National Semiconductor
2900 Semiconductor Dr., Santa Clara, CA 95052; (408) 721-5000, www.national.com.

TAGS: Components
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