SIM_VCC problem


#1

Hi Guys,

I’m new to WS6318 and started working on this recently. Till now I hv successfully made my module ON but i’m not getting SIM_Vcc voltage,it is always at 0V.I’m using 6 pin sim.Also I’m confused abt SIM_PRES pin .I don’t understand whether to connect to Vcc_2V8 or to SIM_Vcc.
In the beginning I tried connecting the SIM_PRES to Supply (3.5V with pull up) and Gnd with pull down ,so do I hv damage the WS6318 though in datasheet they have mentioned that min voltage is 2.4V.
Please help me in sorting out this problem . :frowning:

thanks in advance.


#2

Hi Friends,

I want to add some more things which I hv noticed. While switching ON the module I found that SIM_Vcc gives some voltage for a fraction of second and then goes to zero. After that I hv connected a pull up resistor of 200K with VCC_2V8. So it draws more 40mA of current. Can anyone tell me why it draws more current when i connect SIM_PRES with pull up resistor. And still no SIM_Vcc

Thanks & regards,

Santu


#3

Hi there,

I got the thing working.


#4

AM also facing same problem, sim_vcc voltage coming for fraction of second and going down. am using 6pin for simcard and SIM_PRES is conneted to VCC_2V8 when it is not used.

Still am getting response of SIM not getting detected can you help me how did u resolve this issue ?

Thanks,
Deebak