Lithium battery for nrf51822

[Tizana]

hi,

I'm designing a board with nrf51822 chip. this board work on 2450 lithium rechargeable battery and it contain an MCP73831T circuit which is responsible of recharging the battery.

the MCP73831T circuit contain a STATUS output which indicate the charge STATUS. this output i want to use it as an input to the nrf51822 in order to detect the charging status level.

this output had 3 stats, low, high and high impudence.

my questions :

1/is there anyway that the nrf51822 input can detect the High Z level ? if not how can i do to read these 3 status ?

2/ the MCP73831T chip is working on a different voltage level with the nrf51822 ! the nrf51822 is powered through a step-down DC-DC converter and not directly through the battery.

so this is why i'm trying to figure out a way to connect the STATUS signal from MCP73831T to the nrf51822 .

thx,

[AmbystomaLabs]

The final solution has to be two parts. One is the output reduced to 51822 VDD to detect Hi/Lo. The other will need to be a driven solution to detect high Z.

There is no reason to use a complicated solution like the spst switch. A single fet or a zener and resistor can accomplish the voltage change.