8-bit PIC® MCU Low Power Brown-Out Reset

Last modified by Microchip on 2023/11/22 16:31

The Low Power Brown-out Reset (LPBOR) is similar to the Brown-Out Reset (BOR) and will hold a PIC® microcontroller (MCU) in reset when the Vdd drops below a low power brown out threshold voltage (VLPBOR).

Not all devices have LPBOR but most newer 8-bit PIC® MCU devices do include it.

The difference between a BOR and LPBOR is the current draw. In Sleep mode or low current requirement applications, the LPBOR may be helpful. It will draw less current, when operating, than the BOR.

Enable/Disable LPBOR

The LPBOR is enabled or disabled by a bit setting in a configuration register. The example below is pulled from the PIC16(L)F1708 datasheet.

Enable/Disable LPBOR

LPBOR Reset Voltage Threshold

The LPBOR only has one threshold vs. the BOR which may have more than one. The tolerance for the LPBOR trip point is also larger when compared to the BOR. LPBOR also will react slower to a Vdd drop than the BOR. These are all considerations when choosing the lower current draw LPBOR vs the BOR.

The LPBOR Threshold Voltage is specified in the Electrical Characteristics of the device's datasheet. It will be listed as the Vlpbor voltage similar to the chart below.

LPBOR Reset Voltage Threshold