+5V, Low-Power µP Supervisory Circuits
with Adjustable Reset/Watchdog
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
WATCHDOG TIMER
WDI, WDS Input Threshold
WDI Pulse Width
WDI, WDS Leakage Current
WDI Sink/Source Current
(Note 4)
Watchdog Timeout Period
(Note 3)
t
WD
V
IH
V
IL
t
WP
V
CC
= 4.5V to 5.5V
V
CC
= 2V to 4.5V
Extended mode disabled
Extended mode enabled
WDS = GND, C
SWT
= 1500pF
WDS = V
CC
, C
SWT
= 1500pF
2.8
1.4
±70
4.0
2.0
5.2
2.6
30
60
±1
0.7V
CC
0.3V
CC
V
ns
µA
µA
ms
sec
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX6301–MAX6304
Note 1:
Reset is guaranteed valid from the selected reset threshold voltage down to the minimum V
CC
.
Note 2:
VDS = V
CC
, WDI unconnected.
Note 3:
Precision timing currents of 500nA are present at both the SRT and SWT pins. Timing capacitors connected to these nodes
must have low leakage consistent with these currents to prevent timing errors.
Note 4:
The sink/source is supplied through a resistor, and is proportional to V
CC
(Figure 8). At V
CC
= 2V, it is typically ±24µA.
__________________________________________Typical Operating Characteristics
(C
SWT
= C
SRT
= 1500pF, T
A
= +25°C, unless otherwise noted.)
RESET TIMEOUT PERIOD
vs. C
SRT
6301-4 TOC-01
EXTENDED-MODE
WATCHDOG TIMEOUT PERIOD vs. C
SWT
(WDS = V
CC
)
6301-4 TOC-02
NORMAL-MODE
WATCHDOG TIMEOUT PERIOD vs. C
SWT
(WDS = GND)
V
CC
= 5V
WATCHDOG TIMEOUT PERIOD (ms)
6301-4 TOC-03
10,000
RESET TIMEOUT PERIOD (ms)
10,000
WATCHDOG TIMEOUT PERIOD (sec)
V
CC
= 5V
V
CC
= 5V
10,000
1000
1000
1000
100
100
100
10
10
10
1
1
1
0
0.001 0.01
0.1
1
C
SRT
(nF)
10
100
1000
0
0.001 0.01
0.1
1
C
SWT
(nF)
10
100
1000
0.1
0.001 0.01
0.1
1
C
SWT
(nF)
10
100
1000
_______________________________________________________________________________________
3