AS3668 Datasheet, PDF (1/60 Pages) ams AG – 4 Channel Breathl ight Cont rol ler

Data Sheet
AS3668
4 Channel Breathlight Controller
1 General Description
The AS3668 is a 4-channel LED driver designed to produce lighting
effects for portable devices. A highly efficient charge pump enables
LED driving over full Li-Ion battery voltage range. The device is
equipped with an internal program memory, which allows control of
LED patterns even without processor control. This helps the whole
system to save power and extend for example battery life time in
every mobile application. The AS3668 maintains excellent efficiency
over a wide operating range by automatically selecting the best
charge pump gain based on the LED forward voltage requirements
and the device input voltage.
Furthermore the chip supports an automatic power-save mode which
gets active when LED outputs are not active. The special power-
save mode has a extremely low current consumption below 10µA
(typ.).the AS3668 has an I2C-compatible control interface which
supports two slave address without having a dedicated address
selection pin. For fancy lighting effects synchronized with an audio
signal the device supports special digital filter modes in order to
make music literally visible on the 4 independent configurable
current sources.
The AS3668 is available in a very tiny 12-pin WL-CSP
(1.255x1.680mm) 0.4mm pitch package.
Figure 1. AS3668 Block Diagram
2 Key Features
High efficiency capacitive 60mA charge pump with 1:1 and 1:2
mode
Automatic mode switching for charge pump
Automatic Pattern Mode without digital control
Highly accurate 4 Channel High Side 25.5mA current sources
Audio Controlled Lighting with internal digital filters
Charge Pump with soft start and overcurrent/short circuit pro-
tection
Integrated “easy to use” pattern generator for breathlight LED
function with logarithmic dimming
Small application circuit
Minimum number of external components
Available in 12-pin WL-CSP (1.255x1.680mm) with 0.4mm pitch
3 Applications
The product is perfect for Mobilephones, MP3 Player, Portable
Navigation Devices, Digital Cameras, USB Dongles/Modems, Game
Controllers and can be used for fun and indicator lights, backlighting
and as programmable current sources.
www.austriamicrosystems.com/AS3668
Revision 1.11
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