www.austriamicrosystems.com/AS3643

1.5-4

30 - 33

AS3643

Datasheet, Confidential - A p p l i c a t i o n I n f o r m a t i o n

At the pin GND a single via (or more vias, which are closely combined) connects to the common ground plane. This

via(s) will isolate the DCDC high frequency currents from the common ground (as most high frequency current will flow

between Loop1 and Loop2 and will not pass the ground plane) - see the ‘island’ in Figure 31.

Figure 31. Layout recommendation

Note: If component placement rules allow, move all components close to the AS3643 to reduce the area and length

of Loop1 and Loop2.

ommended to filter high frequency noise for the power supply of AS3643. This capacitor should be as close as possi-

ble to the GND/VIN pins of AS3643.

5V Operating Mode

The AS3643 can be used to power a 5V system (e.g. audio amplifier). The operating mode is selected by setting regis-

ter bit const_v_mode (page 23)=1. In this operating mode, the current sinks are disabled and cannot be switched on

(no flash/torch operation is possible).

Note: There is always a diode between VIN and VOUT1/2 due to the internal circuit. Therefore VOUT1/2 cannot be

completely switched off

Figure 32. 5V Operating Mode

  

   

  

 

 

   

 





 



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