Reply
Posts: 4
Registered: ‎04-06-2017

Does si4684 have power down mode?

If it has a power down mode, how to enter the power down mode by software?

 

Colman

 

Posts: 68
Registered: ‎02-15-2015

Re: Does si4684 have power down mode?

There's a low power mode available in hardware - as long as the RSTB pin is held low, the device is in a low-power mode.

PowerDown

 

As far as I know, there's no way to enter a low-power mode from software.

 

Best regards,

Andi

Posts: 4
Registered: ‎04-06-2017

Re: Does si4684 have power down mode?

Thank you.

 

But I need a software method as I don't have extra IO pin to control the RSTB pin.

 

Colman

 

Posts: 68
Registered: ‎02-15-2015

Re: Does si4684 have power down mode?

Are you sure you can use the chip correctly without any control over the RSTB pin? To what is the pin connected in your design?

 

I am asking, because for correct operation, you need to hold the RSTB pin low for at least 10µs after power-on. Please refer to the datasheet:

 


6.5.3. OPERATIONAL
After software has been loaded, the BOOT command causes the Si4684 to enter the OPERATIONAL state, which is the highest-power state.

The Si4684 can be returned to the RESET state by asserting (holding low) the RSTB pin.

Figure 12 shows required reset, startup, and shutdown timings for the Si4684. RSTB must be held low (asserted) during any power supply transitions and remain asserted for 10 µs after all power supplies are stable as specified in Figure 12. Failure to assert RSTB as indicated here may cause the device to malfunction and may result in permanent device damage.


 

Figure 12 - Reset, Startup and Shutdown timing

 

 

Best regards,

Andi

Posts: 4
Registered: ‎04-06-2017

Re: Does si4684 have power down mode?

The chip's RSTB is connected to system reset. I just want to power down the chip without resetting the whole system,

 

Colman

Posts: 68
Registered: ‎02-15-2015

Re: Does si4684 have power down mode?


colman wrote:

The chip's RSTB is connected to system reset.  


Ok, that works.

 


colman wrote:

I just want to power down the chip without resetting the whole system,


As far as I know, this is not possible (there does not seem to be a "power down" command. 

 

Best regards,

Andi