Power-On Reset Characteristics - Holtek HT48RA5 Technical Document

A.C. Characteristics
Symbol Parameter
f
System Clock (Crystal OSC)
SYS1
f
System Clock (RC OSC)
SYS2
f
Timer I/P Frequency (TMR0/TMR1)
TIMER
t
Watchdog Oscillator Period
WDTOSC
Watchdog Time-out Period
t
WDT1
(WDT OSC)
t Watchdog Time-out Period (f
WDT2
t
External Reset Low Pulse Width
RES
t
System Start-up Timer Period
SST
t Low Voltage Width to Reset
LVR
t
Interrupt Pulse Width
INT
Note: t =1/(f )
SYS SYS

Power-on Reset Characteristics

Symbol Parameter
VDD Start Voltage to Ensure
V
POR
Power-on Reset
VDD raising rate to Ensure
RR
VDD
Power-on Reset
Minimum Time for VDD Stays at
t
POR
V to Ensure Power-on Reset
POR
V
D D
t
P O R
Rev. 1.40
Test Conditions
V Conditions
DD
¾
2.0V~5.5V
¾
3.3V~5.5V
¾
2.0V~5.5V
¾
3.3V~5.5V
3V
50% duty
5V
3V
5V
3V
Without WDT prescaler
5V
¾
/4)
Without WDT prescaler
SYS
¾
Power-up reset or
¾
wake-up from HALT
¾
¾
Test Conditions
V Conditions
DD
¾
¾
¾
R R
V D D
V
P O R
T i m e
5
HT48RA5/HT48CA5
Min. Typ.
¾
400
¾
400
¾
400
¾
400
¾
0
¾
0
45 90
¾
32 65
11 23
8 17
¾
1024
¾ ¾
1
¾
1024
¾ ¾
1
¾ ¾
1
Min. Typ.
¾ ¾ ¾
¾ ¾
0.05
¾ ¾
200
Ta=25°C
Max. Unit
4000 kHz
8000 kHz
4000 kHz
8000 kHz
4000 kHz
8000 kHz
ms
180
ms
130
46 ms
33 ms
¾
t
SYS
¾ ms
¾
t
SYS
¾
ms
¾ ms
Max. Unit
0 mV
¾
V/ms
¾
ms
May 22, 2009