178
8006K–AVR–10/10
ATtiny24/44/84
Two versions of power-on reset have been implemented, as follows.
20.5.1
Standard Power-On Reset
This implementation of power-on reset existed in early versions of ATtiny24/44/84. The table
below describes the characteristics of this power-on reset and it is valid for the following devices,
only:
ATtiny24, revision D, and older
ATtiny44, revision C, and older
ATtiny84, revision A
Note:
Revisions are marked on the package (packages 14P3 and 14S1: bottom, package 20M1: top)
Notes:
1. Values are guidelines only.
2. Threshold where device is released from reset when voltage is rising.
3. The power-on reset will not work unless the supply voltage has been below VPOA.
20.5.2
Enhanced Power-On Reset
This implementation of power-on reset exists in newer versions of ATtiny24/44/84. The table
below describes the characteristics of this power-on reset and it is valid for the following devices,
only:
ATtiny24, revision E, and newer
ATtiny44, revision D, and newer
ATtiny84, revision B, and newer
Notes:
1. Values are guidelines only.
2. Threshold where device is released from reset when voltage is rising.
3. The Power-on Reset will not work unless the supply voltage has been below VPOA.
Table 20-5.
Characteristics of Standard Power-On Reset. T
A = -40 to +85°C
Symbol
Parameter
Units
VPOR
Release threshold of power-on reset
(2)0.7
1.0
1.4
V
VPOA
Activation threshold of power-on reset
(3)0.05
0.9
1.3
V
SRON
Power-on slope rate
0.01
4.5
V/ms
Table 20-6.
Characteristics of Enhanced Power-On Reset. T
A = -40 to +85°C
Symbol
Parameter
Units
VPOR
Release threshold of power-on reset
(2)1.1
1.4
1.6
V
VPOA
Activation threshold of power-on reset
(3)0.6
1.3
1.6
V
SRON
Power-On Slope Rate
0.01
V/ms