DC/DC internal converter

[angel]

Hi Nordic,

We are trying to supply the chip nRF51422 with a Li-Ion battery. The nominal voltage is 3.7V, but as it is known, when full, this voltage can reach up to 4.2V. My question is, can the DC/DC be supplied with this kind of cells? Because I am reading in the documentation that it can only be supplied up to 3.9V. How do people solve this? I guess a lot of people are suplying this chip with this kind of cells. Do I need an external regulator?

Thanks Nordic!

[Wojtek]

According to nRF51422 Product Specification v3.2 3.9V is the absolute maximum, it is not recommended to work on such a high voltage.

Look at the Table 20 in chapter 7 of the specification - it is stated that for both, internal LDO and DC/DC converter, maximum supply voltage is 3.6V.

If You want to use such a cell, you NEED to use some external LDO or DC/DC converter to lower the voltage that is supplied to the chip.

[angel]

Thanks man, will find a different solution then!

Best wishes!