ne56625-20 NXP Semiconductors, ne56625-20 Datasheet - Page 5

• Manufacturer Part Number: ne56625-20
• Description: Ne56625-20 System Reset With Watchdog Timer
• Manufacturer: NXP Semiconductors

4. ‘Reset response time’ is the duration from when the supply voltage sags below the lower detection threshold (V
1. ‘Watchdog monitoring time’ (t
2. ‘Watchdog reset time’ (t
3. The power-on reset delay or hold time is the duration measured from the time V
5. Reset rise and fall times and Battery Check rise and fall times are measured at 10% and 90% output levels.
6. Watchdog monitoring time (t
Philips Semiconductors
AC ELECTRICAL CHARACTERISTICS
Characteristics measured with V
NOTES:
2003 Oct 15
t
t
t
t
t
t
t
t
t
t
t
t
SYMBOL
P1
CLKW
CLK
WDM
WDR
PR
PDR
PDB
RR
FR
RB
FB
varying the C
System reset with Watchdog timer
pulse occurs (see Figure 17). A reset signal is output if a clock pulse is not input during this time.
power-on reset release is experienced (RESET output HIGH).
output LOW).
to 2.2 F.
Formula 1. Calculation for approximate t
Example: When C
Minimum power supply pulse width for
detection
Clock input pulse width
Clock input cycle
Watchdog monitoring time (Notes 1, 6)
Watchdog reset time (Notes 2, 6)
Power-on reset delay time (Notes 3, 6)
RESET propagation delay time (Note 4)
Battery Check propagation delay time
(Note 4)
RESET rise time (Note 5)
RESET fall time (Note 5)
Battery Check rise time (Note 5)
Battery Check fall time (Note 5)
T
capacitance. The times can be approximated by applying the following formula. The recommended range for C
T
t
t
t
t
t
t
PR
WDM
WDR
PR
WDM
WDR
= 0.022 F and R
WDR
(ms)
PARAMETER
(ms)
100 ms
(ms)
2.0 ms
) is the reset pulse width. Do not confuse this with the power-on reset delay time (t
100 ms
WDM
CC
WDM
4500
= 2.6 V, and T
), Watchdog reset time (t
90
4500
) is the duration from the last pulse (negative-going edge) of the timer clear clock pulse until reset output
C
C
CT
T
T
C
( F)
( F)
= open:
PR
T
( F)
, t
amb
WDM
= 25 C, unless otherwise specified.
, and t
V
4.0 V
V
WDR
CC
WDR
V
CC
CC
= falling; R
= falling; R
), and power-on reset delay time (t
values:
C
= rising from 0 V; C
R
R
R
R
negative-going V
LR
LR
T
LB
LB
= 0.022 F; R
= 100 k ; C
= 100 k ; C
5
= 10 k ; C
= 10 k ; C
C
CONDITIONS
T
LR
LB
= 0.022 F
= 100 k ; C
= 10 k ; C
LB
LB
CC
LR
LR
CT
CC
= 15 pF
= 15 pF
T
= 15 pF
= 15 pF
exceeds the upper detection threshold (V
= open
pulse
= 0.022 F
LB
LR
= 15 pF
= 15 pF
5.0 V
PR
) during power-on can be modified by
MIN.
8.0
3.0
1.0
20
50
50
–
–
–
–
–
–
PR
SL
).
TYP.
100
100
) and reset occurs (RESET
2.0
10
10
10
10
–
–
–
2
2
NE56625-20
MAX.
150
150
T
SHR
3.0
–
–
–
–
–
–
–
–
–
is 0.0022 F
) and
Product data
UNIT
ms
ms
ms
s
s
s
s
s
s
s
s
s