32.5 System and Reset Characteristics

Table 32-6. Reset, Brown-out and Internal Voltage Characteristics⁽¹⁾
Symbol	Parameter	Condition	Min.	Typ	Max	Units
V_POT	Power-on Reset Threshold Voltage (rising)		0.7	1.5	1.7	V
V_POT	Power-on Reset Threshold Voltage (falling)⁽²⁾		0.6	1.1	1.7	V
SR_ON	Power-on Slope Rate		0.01	-	9	V/ms
V_RST	RESET Pin Threshold Voltage		0.2 V_CC	-	0.9 V_CC	V
t_RST	Minimum pulse width on RESET Pin		-	-	2.5	μs
V_HYST	Brown-out Detector Hysteresis		-	50	-	mV
t_BOD	Min. Pulse Width on Brown-out Reset		-	2	-	μs
V_BG	Bandgap reference voltage		1.0	1.1	1.2	V
t_BG	Bandgap reference start-up time	V_CC=2.7 T_A=25°C	-	40	70	μs
I_BG	Bandgap reference current consumption	V_CC=2.7 T_A=25°C	-	10	-	μA

Note:

Values are guidelines only.
The Power-on Reset will not work unless the supply voltage is below V_POT (falling)

Table 32-7. BODLEVEL Fuse Coding⁽¹⁾⁽²⁾
BODLEVEL [2:0] Fuses	Min. V_BOT	Typ. V_BOT	Max V_BOT	Units
111	BOD Disabled
110	1.7	1.8	2.0	V
101	2.5	2.7	2.9
100	4.1	4.3	4.5
011 - 000	Reserved

Note: V_BOT may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is tested down to V_CC = V_BOT during the production test. This guarantees that a Brown-Out Reset will occur before V_CC drops to a voltage where correct operation of the microcontroller is no longer guaranteed. The test is performed using BODLEVEL = 110, 101 and 100.

ATmega324PB

32.5 System and Reset Characteristics