AS3668_07 datasheet(28/59 Pages) AMSCO

28 / 59 page

www.ams.com/AS3668

Revision 1.13

28 - 59

AS3668

Data Sheet - Detailed Description

Figure 37. Timing Diagram Startup Modes

Figure 38. Typical Application Automatic Pattern Startup

The application in Figure 38 shows the AS3668 connected to a CPU and a typical charger. Most of the stand alone chargers do have a open

drain output for charger indication with a LED. This output pin can be used to control AS3668. If the charger is active the GPIO/AUDIO_IN input

pin of AS3668 is pulled high. The chip starts up with a default pattern on CURR1output. With this special mode it is possible to indicate charging

using for example the RGB LED connected to AS3668 although the CPU is not running. This use case can happen if the battery of a device is

almost fully discharged and the CPU can not start up because the battery voltage is too low in trickle charge mode. The automatic pattern start-

up mode allows the operate the LED on AS3668 without I²C interaction with the CPU. AS3668 starts up in automatic pattern start-up mode with

the default pattern shown in Figure 39. Please mind that the pattern is only active for current source CURR1.

AS3668 Datasheet(PDF) 28 Page - ams AG