I have a question about the NRF518222, we using 3v coin cell battery as power for Ldo working mode. The connection between the devices and mobile phones, regular, disconnection and reconnection. How to resolve this problem?
I have a question about the NRF518222, we using 3v coin cell battery as power for Ldo working mode. The connection between the devices and mobile phones, regular, disconnection and reconnection. How to resolve this problem?
Dave_couling : I have using the NRF518222 in LDO power mode. Not in 1.8V power mode. When using the new coin cell , the volatge has obvious drop(0.15V)。 The connection will be disconnect about 30mintues. I am very confused by it ,and the ble 4.0 have this problem?
RK:
Thanks for you reply. the board is designed by us , we reference the Ldo mode. The crystals is epson and TXC。 We have develop a product using lithium battery. The product is more stable than using coin cell. But now, we must using coin cell in this product .so i want resolve this problem. And we have tested the product production by other company ,there is same problem as we met. So we doubt the coin cell(the power system). Phenomenon is break rewiring system, we still not sure is a software reset signal is bad, button cell adopt "mode, the voltage instability. This is our actual test condition.
Dave_couling : I have using the NRF518222 in LDO power mode. Not in 1.8V power mode. When using the new coin cell , the volatge has obvious drop(0.15V)。 The connection will be disconnect about 30mintues. I am very confused by it ,and the ble 4.0 have this problem?
RK:
Thanks for you reply. the board is designed by us , we reference the Ldo mode. The crystals is epson and TXC。 We have develop a product using lithium battery. The product is more stable than using coin cell. But now, we must using coin cell in this product .so i want resolve this problem. And we have tested the product production by other company ,there is same problem as we met. So we doubt the coin cell(the power system). Phenomenon is break rewiring system, we still not sure is a software reset signal is bad, button cell adopt "mode, the voltage instability. This is our actual test condition.
Phenomenon is break rewiring system, we still not sure is a software reset signal is bad, button cell adopt "mode, the voltage instability. This is our actual test condition.
There are not issues with running off of a Coin Cell battery other than to design with the note that Coin Cell batteries have high Internal Resistances, especially towards the latter half of their charge. You need to verify that you're peak currents do not cause the voltage to drop below 1.8V. I would start checking the voltage drops you observe on the Vcc pins of your nRF chip during RF events. Also make sure you don't have other sub-systems on your board (I don't know what else is on your board) which could further the voltage drops.
Also just in general, please be very clear about what exactly the fault is. It is still unclear based on your given information.
DC
Unfortunately you haven't provided enough information for me to be able to help. There are many many possible root causes for such a situation. I would need more information to be able to help.
What are you connecting to? iPhone/Android?
What version of SDK?
What version of softDevice
What type of antenna?
Have your crystal loading capacitors been properly tuned?
What is your steady state (System-ON) input current level?
What is the peak current level?
Dave_couling: SDK version is 7.0 Softdevice is 7.1 Antenna is ceramic bluetooth antenna. 32K is using RC internal in Chipset. Steady state is about 400uA. Peak Current is about 0.6mA.
Steady State current of 400uA seems a bit high.
Are you sure you initialized the Softdevice to use the internal RC? example: SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_250MS_CALIBRATION, true);
You peak current should be much higher than 0.6mA. Are you measuring with an oscilloscope?