sim900 auto-power down when using with Beaglebone Black

Hello, I want to use a sim900 module with beaglebone black. I also want to power the module from beaglebone black, so I use 5V output pin on it. But when I power it up the SIM900 status led starts blinking 64/800ms and after a few seconds it stops blinking and powers off. i see the voltage on oscilloscope and I see that there is high drop out (about 500mV) on power pin. How can I solve this problem? (I used two 220uF capacitor in parallel). The beaglebone black has two 5V output pin, one directly from the adapter plug and one from output of its power management IC (tps65217). When I use the 5V that comes directly from adapter, the module powers up and connects to network but sometimes when communicating with network (for example by gprs) it power off but when using 5V output of its PMIC it powers off even without connecting to network.

Hi,

current is the keyword.

How much current draws your SIM900 (peak)?
and how much current can be supplied by the beaglebone?

--> read the corresponding datasheets.

Klaus

KlausST said:

Hi,

current is the keyword.

How much current draws your SIM900 (peak)?
and how much current can be supplied by the beaglebone?

--> read the corresponding datasheets.

Klaus

Click to expand...

It is said in datasheet that the module draws up to 2A peak when communicating with network. I used a 5V 2.5A adapter and still it had high drop out and it sometimes powers off.

Hi,

You give just half of informations:

Consider:
* How much current draws the beaglebone board?
* Are there any other periferals connected, that draw current from the supply? (every USB device, SD-Card, display, audio, camera, add-on board... )

Klaus

KlausST said:

Hi,

You give just half of informations:

Consider:
* How much current draws the beaglebone board?
* Are there any other periferals connected, that draw current from the supply? (every USB device, SD-Card, display, audio, camera, add-on board... )

Klaus

Click to expand...

The adapter is just connected to the beaglebone black and it consumes about 300mA.