AS3668-EB

Data Sheet AS3668 4 Channel Breathlight Controller 1 General Description 2 Key Features High efficiency capacitive 60mA charge pump with 1:1 and 1:2 The AS3668 is a 4-channel LED driver designed to produce lighting mode effects for portable devices. A highly efficient charge pump enables LED driving over full Li-Ion battery voltage range. The device is Automatic mode switching for charge pump equipped with an internal program memory, which allows control of Automatic Pattern Mode without digital control LED patterns even without processor control. This helps the whole system to save power and extend for example battery life time in Highly accurate 4 Channel High Side 25.5mA current sources every mobile application. The AS3668 maintains excellent efficiency Audio Controlled Lighting with internal digital filters over a wide operating range by automatically selecting the best charge pump gain based on the LED forward voltage requirements Charge Pump with soft start and overcurrent/short circuit pro- and the device input voltage. tection Furthermore the chip supports an automatic power-save mode which Integrated easy to use pattern generator for breathlight LED gets active when LED outputs are not active. The special power- function with logarithmic 12bit dimming save mode has a extremely low current consumption below 10 A Small application circuit (typ.).the AS3668 has an I2C-compatible control interface which Minimum number of external components supports two slave address without having a dedicated address selection pin. For fancy lighting effects synchronized with an audio Available in 12-pin WL-CSP (1.255x1.680mm) with 0.4mm pitch signal the device supports special digital filter modes in order to make music literally visible on the 4 independent configurable 3 Applications current sources. The AS3668 is available in a very tiny 12-pin WL-CSP The product is perfect for Mobilephones, MP3 Player, Portable (1.255x1.680mm) 0.4mm pitch package. Navigation Devices, Digital Cameras, USB Dongles/Modems, Game Controllers and can be used for fun and indicator lights, backlighting and as programmable current sources. Figure 1. AS3668 Block Diagram www.ams.com/AS3668 Revision 1.13 1 - 59AS3668 Data Sheet - Applications Contents 1 General Description .................................................................................................................................................................. 1 2 Key Features ............................................................................................................................................................................ 1 3 Applications .............................................................................................................................................................................. 1 4 Pin Assignments ....................................................................................................................................................................... 4 4.1 Pin Description .....................................................................................................................................................................................5 5 Absolute Maximum Ratings ...................................................................................................................................................... 6 6 Electrical Characteristics .......................................................................................................................................................... 7 6.1 Timing Characteristics ..........................................................................................................................................................................9 6.2 Timing Diagrams ..................................................................................................................................................................................10 7 Typical Operating Characteristics ................................................................................................................................................11 8 Detailed Description ............................................................................................................................................................... 14 8.1 Charge Pump .....................................................................................................................................................................................14 8.1.1 Charge Pump Mode Switching ..................................................................................................................................................15 8.1.2 Soft Start ....................................................................................................................................................................................15 8.1.3 Unused Charge Pump ...............................................................................................................................................................15 8.1.4 Charge Pump Control Register ..................................................................................................................................................16 8.2 Current Sources .............................................................................................................................................................................16 8.2.1 Unused Current Sources ...........................................................................................................................................................17 8.2.2 Current Source Registers ...........................................................................................................................................................18 8.3 Power - On Reset ...............................................................................................................................................................................19 8.4 VBAT Monitor .....................................................................................................................................................................................20 8.4.1 VBAT Monitor Registers .........................................................................................................................................................21 8.5 Temperature Supervision ...................................................................................................................................................................21 8.6 IC Serial Interface Bus ......................................................................................................................................................................22 8.6.1 IC Device Address Byte ............................................................................................................................................................24 8.6.2 Command Byte ..........................................................................................................................................................................24 8.6.3 IC Device Address Selection ....................................................................................................................................................25 8.7 Operating Modes ................................................................................................................................................................................25 8.7.1 GPIO/AUDIO IN Automatic Pattern Start-up Mode ..................................................................................................................27 8.8 General Purpose Input / Output .........................................................................................................................................................29 8.8.1 Unused General Purpose Input / Output ...................................................................................................................................30 8.8.2 GPIO Control Register.............................................................................................................................................................30 8.9 Audio Input .........................................................................................................................................................................................30 8.9.1 Audio Control Register .............................................................................................................................................................32 8.10 LED Pattern Configuration ...............................................................................................................................................................34 8.10.1 Single Pulse Mode ...................................................................................................................................................................34 8.10.2 Multiple Pulse Mode ................................................................................................................................................................ 35 8.10.3 Frame Mask Mode ...................................................................................................................................................................36 8.10.4 Frame Start Delay Mode ..........................................................................................................................................................37 8.10.5 GPIO Toggle Mode ..................................................................................................................................................................37 8.10.6 LED Pattern Control Registers ...............................................................................................................................................38 9 Register Map ........................................................................................................................................................................ 45 10 Application Information ........................................................................................................................................................ 48 10.1 LED Software Implementation Examples .........................................................................................................................................48 www.ams.com/AS3668 Revision 1.13 2 - 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