10.3 Low-Power Brown-out Reset (LPBOR)

The Low-Power Brown-out Reset (LPBOR) circuit provides alternative protection against Brown-out conditions. When VDD falls below the LPBOR threshold, the device is held in Reset. When this occurs, the BOR bit of the PCON0 register is cleared to indicate that a Brown-out Reset occurred. The BOR bit will be cleared when either the BOR or the LPBOR circuitry detects a BOR condition.

The LPBOR feature can be used with or without BOR enabled. When used while BOR is enabled, the LPBOR can be used as a secondary protection circuit in case the BOR circuit fails to detect the BOR condition. Additionally, when BOR is enabled except while in Sleep (BOREN[1:0] = 10), the LPBOR circuit will hold the device in Reset while VDD is lower than the LPBOR threshold, and will also re-arm the POR (see 39.4.5 Reset, WDT, Oscillator Start-up Timer, Power-up Timer, Brown-out Reset and Low-Power Brown-out Reset Specifications for LPBOR Reset voltage levels).

When used without BOR enabled, the LPBOR circuit provides a single Reset trip point with the benefit of reduced current consumption.

Figure 10-3. LPBOR, BOR, POR Relationship