CC2564 CLK_REQ_OUT Configuration?

Markus,

Are you using a specific board with the CC2564 or are you using the CC2564 directly in your application?

By default, CLK_REQ_OUT has the following configuration:

In shutdown it's high impedance with a Pulldown

In the default active mode it's Output high

In Deep Sleep it's Output low

I don't believe you can configure its behavior beyond this, but I am checking with other team members.

I need the signal for setting the voltade regulators in power save mode, is it not possible to activate the function? (also I am thinking of using an oscillator because it is not easy to find an 20ppm crystal in 85/-40 degreas)

Markus,

     The PAN13xx modules do no support this functionality since they contain the XTAL inside. But you could control this voltage regulators from the MSP430 side.

Regards,

Hi Miguel,

I am not using an an MSP430 or a PAN13xx. I am using the CC2564 together with another MCU (the MSP430 packages is to large for my application). Everything works fine but we are not satisfied with the power consumption in deep sleep mode.

I would be very starange if there isn´t a Clock request signal to the CC2564, e.g:

- In my case I would maybe want to use it to connect it to a standalone oscillator which has better tolerance especially in low temperatures (-40 degrees). But it consume to much power in sleep mode so I want to shut it down (and I also want connect it to my regulator but it is not very important).

- Maybe you have a central clock logic (not in this specific case) where different subssystems uses the clock but you want to shut it down if no-one need it

Br
Markus

Hi Gustavo,

I am using the CC2564 together with another MCU (the MSP430 packages is to large for my application). Everything works fine but we are not satisfied with the power consumption in deep sleep mode.

The default behavour would be fine but the CLK_REQ_OUT is always output high in deep sleep mode (but the crystal is turned off correctly).

Do you have a document describing the Deep sleep mode (including the CLK_REQ_OUT) functionality and configuration?

The block connections are:
- CC2564 is connected to the host MCU with UART (4 wires) 4Mbit.
- The CC2564 connected to a 26MHz crystal
- The radio voltage regulators (1.8 and 2.85V) has a power saving mode signal connected to the CLK_REQ_OUT signal (active low).
- I am also thinking of using an oscillator instead because of the better tolerances in -40 degrees.

Br
Markus

Markus,

As previously mentioned, in deep sleep CLK_REQ_OUT should be output low. Perhaps you have a short in your board that's connecting it to VCC. This would explain an extra current draw since there would be contention between VCC and the pin pulling it low.

Gustavo

I don´t think it is shorted to at least VCC because CLK_REQ goes low when the CC2564 shut_down pin goes low.

Could the CLK_REQ function automaticly be disactivated because we are using an crystal?

Is it possible to manually configure the CLK_REQ function?

/Markus