Table 1. Reset, Brown-out and Internal
Voltage Characteristics(1)| Symbol |
Parameter |
Condition |
Min. |
Typ |
Max |
Units |
|---|
| VPOT |
Power-on Reset Threshold Voltage (rising) |
|
0.7 |
1.0 |
1.4 |
V |
| Power-on Reset
Threshold Voltage (falling)(2) |
|
0.05 |
0.9 |
1.3 |
V |
| SRON |
Power-on Slope Rate |
|
0.01 |
- |
4.5 |
V/ms |
| VRST |
RESET Pin Threshold Voltage |
|
0.2 VCC |
- |
0.9 VCC |
V |
| tRST |
Minimum pulse
width on RESET Pin |
|
- |
- |
2.5 |
μs |
| VHYST |
Brown-out Detector Hysteresis |
|
- |
50 |
- |
mV |
| tBOD |
Min. Pulse Width on Brown-out Reset |
|
- |
2 |
- |
μs |
| VBG |
Bandgap reference voltage |
VCC=2.7
TA=25°C |
1.0 |
1.1 |
1.2 |
V |
| tBG |
Bandgap reference start-up time |
VCC=2.7
TA=25°C |
- |
40 |
70 |
μs |
| IBG |
Bandgap reference current consumption |
VCC=2.7
TA=25°C |
- |
10 |
- |
μA |
Note:
- Values are guidelines only.
- The Power-on Reset will not work unless the supply voltage has been below VPOT
(falling)
Table 2. BODLEVEL Fuse Coding(1)| BODLEVEL [2:0] Fuses |
Min. VBOT |
Typ. VBOT |
Max VBOT |
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 |
Reserved |
| 010 |
| 001 |
| 000 |
Note: VBOT may be below nominal
minimum operating voltage for some devices. For devices where this is the case, the device
is tested down to VCC = VBOT during the production test. This guarantees that a Brown-Out Reset will occur
before VCC drops to a voltage where correct operation of
the microcontroller is no longer guaranteed. The test is performed using BODLEVEL = 101 and
BODLEVEL = 100 for ATmega48/88/168, and BODLEVEL = 110 and BODLEVEL = 101 for
ATmega48V/88V/168V.