iMAX6 RTC current draw

[miketrench]

We are using a non-rechargeable battery to power the iMAX6 real time clock (SNVS power domain). No mention of the load current in the data sheets or application notes. This information is needed to size the battery (mAh) and determine when the battery should be replaced. Thank you.

[gusarambula]

Hello Mike Trench,

The maximum supply current for VDD_SNVS_IN is shown on table 8 of the i.MX6Q Datasheet (link below). This document sets this number to 275uA; however, this is a maximum except for the footnote stating that during initial power on, VDD_SNVS_IN can draw up to 1 mA if the supply is capable of sourcing that current. If less than 1 mA is available, the VDD_SNVS_CAP charge time will increase

http://cache.nxp.com/files/32bit/doc/data_sheet/IMX6DQCEC.pdf

Unfortunately, this is the only number officially listed on the NXP documentation. However, typical power consumption of VDD_SNVS_IN should be ~48uA in Deep Sleep Mode and ~15uA in Power Down Mode.

I would also recommend considering for your analysis the information in checkbox 2 of Table 2-6 of the i.MX6 Hardware Design Guide (link below) since it specifies the behavior of the current drawn from VDD_SNVS_IN depending on VDD_HIGH_IN voltage.

http://cache.nxp.com/files/32bit/doc/user_guide/IMX6DQ6SDLHDG.pdf