nRF52832 Vdd=3.67V safe without shunt/series regulator?

[Sjoert de Boer]

Hello,

As a power source I am using a battery with an open circuit voltage of 3.67V. The specification states that the recommended absolute maximum supply voltage is 3.6V.

I have thought of a shunt regulator consisting of a zener diode of 3.6V and a series resistor to limit the current through the zener diode while in zener mode. Also an additional LDO has been considered.

As the supply is upmost 0.07V out of spec, what do you guys think? Can I leave the nordic nRF52832 directly connected to the battery, or should i stay in the safe region by adding i.e. an LDO.

The problem is energy consumption, the zener will lower the efficiency. As will the LDO.

In low power mode, only ~2 uA will be drawn as stated in page 77 of the specification. As a maximum i take 20 mA of total current.

Thanks in advance,

Sjoert

[Sigurd]

Hi,

3.67 V is outside the recommended supply voltage (1.7 – 3.6V). Exposing the chip to a voltage above 3.6 V may over time affect the reliability of the chip, and in worst case damage the chip. An external regulator is therefore recommended.

We don’t provide any particular recommendation on regulators, since this will depend on your application, but in the development kits we are using this linear regulator. Note that this has a 300mA output, which may be more than you need.

[Sjoert de Boer]

Hi,

Thanks for your reply :) It is indeed more than I need. I am using a battery that can supply only 40 mA. I'm using a Li-SOCL2 battery. It has a high output impedance, it wont be able to handle current bursts.

Im thinking of adding a supercapacitor along with some power management circuitry to get a stable power supply that can handle current spikes.