nRF9160 Supply voltage


we are using nRF9160 with primary battery,  so we are calculating the power consumption for sleep mode.

While doing the power calculation I have observed that, if 3.3 volts is supplied it takes <2 µA as expected, if 3.9 volts  is supplied it takes 12 mA, if 5.5 volts is supplied it takes 80 mA on sleep.

Since only using primary battery, Board doesn't have voltage regulator, battery voltage is directly supplied to the nRF9160.

Battery voltage around 3.8 volts and nrf is taking 12mA on sleep.

Is it mandatory to supply only 3.3 volts to nrf9160 to reduce power consumption?

Please share your comments.