Rainbow Electronics ATmega128RFA1 - Manual (Page 502)

502
8266A-MCU Wireless-12/09
ATmega128RFA1
34.2 Clock Characteristics
34.2.1 Calibrated Internal RC Oscillator Accuracy
Table 34-2. Calibration Accuracy of Internal RC Oscillator
Frequency V
DEVDD
Temperature Calibration Accuracy
Factory Calibration 16 MHz 3.0V 25°C ± TBD %
User Calibration TBD 1.8V – 3.6V -TBD°C - TBD°C ± TBD %
34.2.2 External Clock Drive
Figure 34-1 External Clock Drive Waveforms
V
IL1
V
IH1
Table 34-3. External Clock Drive
Symbol Parameter Min. Max. Units
1/t
CLCL
Oscillator Frequency 16 MHz
t
CLCL
Clock Period 62.5 ns
t
CHCX
High Time 25 ns
t
CLCX
Low Time 25 ns
t
CLCH
Rise Time 0.1 µs
t
CHCL
Fall Time 0.1 µs
∆ t
CLCL
Change in period from one clock cycle to the next 1 %
34.3 System and Reset Characteristics
Table 34-4. Reset, Brown-out and Internal Voltage Characteristics
Symbol Parameter Condition Min Typ Max Units
Power-on Reset Threshold Voltage
(rising)
TBD V
V
POT
Power-on Reset Threshold Voltage
(falling)
( 1 )
0.3 V
V
PSR
Power-on slope rate TBD V/ms
V
RST
RSTN Pin Threshold Voltage 0.2V
DEVDD
0.9V
DEVDD
V
t
RST
Minimum pulse width on RSTN Pin TBD ns
V
HYS
Brown-out Detector Hysteresis 50 mV
t
BOD
Min Pulse Width on Brown-out Reset 100 ns
V
BG
Bandgap reference voltage V
DEVDD
= 3.0V, T
A
= 25°C 1.2 V
Note: 1. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling).