35.11 RSTCTRL and BOD

Table 35-14. Reset, WDT, Oscillator Start-up Timer, Power-up Timer, Brown-out Detector Specifications
Symbol	Description	Min.	Typ. ✝	Max.	Unit	Conditions
t_RST ^*	RESET pin pulse-width low to ensure a Reset	2.5	—	—	μs
R_{RST_UP}^*	RESET pin pull-up resistor	—	30	—	kΩ
T_OST⁽¹⁾	Oscillator Start-up timer period	—	1024	—	cycles
V_BOD+⁽²⁾	Brown-out Detect voltage, rising slope	—	1.7	1.74	V	BODLEVEL0
		—	1.93	2.00	V	BODLEVEL1
		—	2.65	2.70	V	BODLEVEL2
		—	4.34	4.50	V	BODLEVEL3
V_BOD-⁽²⁾	Brown-out Detect voltage, falling slope	1.62	1.67	—	V	BODLEVEL0
		1.80	1.91	—	V	BODLEVEL1
		2.50	2.62	—	V	BODLEVEL2
		4.10	4.32	—	V	BODLEVEL3
V_{BOD_HYS}	Brown-out Detect hysteresis	—	25	—	mV
t_{BOD_ST}	Brown-out Detect start-up time from sleep	—	40	—	μs
t_{BOD_128Hz}	BOD response time Sampling mode @128 Hz	—	7.8	—	ms	CTRLA.SAMPFREQ = `0x0`
t_{BOD_32Hz}	BOD response time Sampling mode @32 Hz	—	31.3	—	ms	CTRLA.SAMPFREQ = `0x1`
t_{BOD_RST}	Brown-out Reset response time	—	5	—	μs	V_DD = V_BOD - 0.1V
✝ Data in the “Typ.” column is measured at T_A = 25°C and V_DD = 3.0V unless otherwise specified. These parameters are not tested and are for design guidance only. * These parameters are characterized but not tested in production. Note: By design, the Oscillator Start-up Timer (T_OST) counts the first 1024 cycles, independent of frequency. V_DD and GND must be capacitively decoupled as close to the device as possible to ensure these voltage tolerances. Recommended values are 0.1 μF and 0.01 μF in parallel.

Table 35-15. Voltage Level Monitor Threshold Specifications
Symbol	Description	Min.	Typ. ✝	Max.	Unit	Conditions
V_DET ^*	Voltage Detection Threshold	—	5	—	% above BOD threshold	VLMCTRLA.VLMLVL = `0x01`
		—	17	—		VLMCTRLA.VLMLVL = `0x02`
		—	27	—		VLMCTRLA.VLMLVL = `0x03`
✝ Data in the “Typ.” column is measured at T_A = 25°C and V_DD = 3.0V unless otherwise specified. These parameters are for design guidance only and are not tested. * These parameters are characterized but not tested in production.