AS3685A/AS3685B

Datasheet

www.austriamicrosystems.com/

AS3685

(ptr)

Revision 2.2

14 - 24

The low time of the pulses on EN1 for setting the current should be kept short. Then the (generated) signal on

actual driving waveform on EN1.

7.2.2.2 AS3685B Two Wire Interface with Strobe Input

Using the following application schematic, the AS3685B current and mode can be set accurately and the camera

can directly control the exact strobe time:

Figure 20 – AS3685B Two Wire Interface with strobe input

An example driving waveform can be (this uses method B as shown above in section ‘AS3685B Current

Settings’):

Figure 21 – AS3685B Example Two Wire Interface driving waveform

EN2

EN1

off

STROBE

off

GPIO output driving EN2 directly is

tristated and 'STROBE'

defines input EN2

GPIO output driving EN2

directly defines input EN2

Set current with

number of pulses

Enable/Disable current directly by the

camera module using the 'STROBE' input

Flash/Strobe/Indicatior function

dependent on number of previous pulses

ISET

VBAT

EN1

EN2

Vbat

EN1

EN2

Two GPIO Pins to set

current and mode

STROBE

Optional

Strobe Input

AS3685B