The ADM8843 uses charge pump technology to provide the power to drive up to four LEDs. The LEDs are used for back-lighting a color LCD display that has regulated constant current for uniform brightness intensity. The main display can use up to three LEDs, and the sub display uses one LED. The CTRL1 and CTRL2 digital input control pins control the shutdown opera-tion and the brightness of the main and sub displays.
To maximize power efficiency, the charge pump can operate in 1×, 1.5×, or 2× mode. The charge pump automatically switches among 1×/1.5×/2× modes, based on the input voltage, to maintain sufficient drive for the LED anodes at the highest power efficiency.
Improved brightness matching of the LEDs is achieved by a feedback pin that senses individual LED current with a typical matching accuracy of 0.3%.
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|ADM8843: Four White LED Backlight Driver Data Sheet (Rev C, 01/2011) (pdf, 372 kB)||Data Sheets|
Isolating Power in Communication Bus and Gate Drive Applications
Starting with a communications application overview of small power options through the process of selecting the right power products this webcast is a great resource for your communications applications designs.
Innovative Power Reduction Techniques Enable Handset Manufacturers to Provide Media Rich Devices
The demand for mobile devices with high-end features has been rapidly increasing. Features like text messaging, gaming, GPS navigation, web browsing and video playback on high resolution color displays are becoming the norm in today’s portable consumer electronics market.
(LED Journal, August/September 2009)
Charge Pump Application Bulletin
(pdf, 970 kB)
All new applications guide for charge pumps
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|Glossary of EE Terms||Glossary||HTML|
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