ATA8741_14 Datasheet, PDF (178/215 Pages) ATMEL Corporation – Microcontroller with UHF ASK/FSK Transmitter

29.4.3 External Clock Drive
Table 29-2. External Clock Drive
Parameter
Clock frequency
Clock period
High time
Low time
Rise time
Fall time
Change in period from one clock cycle to the next
Symbol
1/t_CLCL
t_CLCL
t_CHCX
t_CLCX
t_CLCH
t_CHCL
Δt_CLCL
29.5 System and Reset Characterizations
V_CC = 2.7 - 5.5V
Min.
Max.
0
10
100
40
40
1.6
1.6
2
V_CC = 4.5 - 5.5V
Min.
Max.
0
20
50
20
20
0.5
0.5
2
Unit
MHz
ns
ns
ns
µs
µs
%
Table 29-3. Reset, Brown-out and Internal Voltage Reference Characteristics⁽¹⁾
Parameter
Symbol
Condition
Min
Typ
Max
Unit
Brown-out detector hysteresis
RAM retention voltage⁽¹⁾
Min Pulse width on brown-out reset
Bandgap reference voltage
Bandgap reference start-up time
Bandgap reference current consumption
Notes: 1. Values are guidelines only.
V_HYST
V_RAM2.
100
250
mV
50
mV
t_BOD
2
ns
V_BG
V_{C C}= 2.7V, T_A = 25°C
1.0
1.1
1.2
V
t_BG
V_{C C}= 2.7V, T_A = 25°C
40
70
µs
I_BG
V_{C C}= 2.7V, T_A = 25°C
10
µA
2. This is the limit to which VDD can be lowered without losing RAM data
Table 29-4. BODLEVEL Fuse Coding⁽¹⁾
Note:
BODLEVEL [2..0] Fuses
111
Min V_BOT
Typ V_BOT
Max V_BOT
BOD Disabled
Unit
110
1.8
101
2.7
100
4.3
011
2.3
V
010
2.2
001
1.9
000
2.0
1. 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.
178 ATA8741 [DATASHEET]
9140E–INDCO–09/14