Hi,
I'm using GPRS Module, which IO operates at 2.8V I'm using LEvel shifter IC MOSFET based
My connection as per the diagram (It's GPRS not GPS).
Whenever I try to communicate over UART, I get these error saying offline.
That level shifter does not support voltages lower than 3V3. I have a REALLY hard time believing that your GPS module works on 2V8 and not 3V3 - can you post a link to the module's datasheet?
It's a GPRS Module not GPS.(sorry In image while writing I wrote it as GPS should be GPRS)
Since it's a mosfet based it should basically support 2.8V right? as long VLOW is 2.8V and VHIGH 3.3V it should be able to communicate right?
1.) Please answer the question in my previous post
2.) Mosfets have operating regions and specs - they don't work for all voltages
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Please find the attached link: http://www.mobiletek.cn/l651e.html
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I agree MOSFETs do have Vgs (threshold) below which they do not operate.
But If you look at the link which I sent you earlier for the level shifter, which says operates from 1.8V to 5V Level shifter.
From the data sheet:
Supply Voltage Range 3.4 ~ 4.2V (3.8V Typ)
Its a 3.3V device.
May I suggest you go and reread the data 'sheets' on the device.
lakshmi123:
- Please find the attached link: http://www.mobiletek.cn/l651e.html
Supply Voltage Range3.4 ~ 4.2V (3.8V Typ)
This leads me to believe this is really a 3V3 device with 3V3 UART. Can you link to the exact documentation that says the UART interface is other than 3V3?
lakshmi123:
2) I agree MOSFETs do have Vgs (threshold) below which they do not operate.
But If you look at the link which I sent you earlier for the level shifter, which says operates from 1.8V to 5V Level shifter.
It says its rated down to 2.8V, but I think 1.8V was a typo on your part.
Thanks for your reply.
I'm not talking on the Supply voltage. Please have look at the IO Voltage
Power_Broker:
This leads me to believe this is really a 3V3 device with 3V3 UART. Can you link to the exact documentation that says the UART interface is other than 3V3?It says its rated down to 2.8V, but I think 1.8V was a typo on your part.
can you please login and download the data sheet for L651 OR
http://test2.acmarcorp.com/uploadedFiles/L651_Hardware%20Design_V1.0.pdf
This level converter also works with 2.8V and 1.8V devices. What really separates this Logic level converter from our previous versions is that you can successful
Power_Broker:
This leads me to believe this is really a 3V3 device with 3V3 UART. Can you link to the exact documentation that says the UART interface is other than 3V3?It says its rated down to 2.8V, but I think 1.8V was a typo on your part.
Haven't heard anything after that.