+5 V, Lo w -P o w e r µP S u p e rvis o ry Circ u it s
w it h Ad ju s t a b le Re s e t /Wa t c h d o g
1–MAX6304
ELECTRICAL CHARACTERISTICS (continued)
(V = +2V to +5.5V, T = T
to T , unless otherwise noted. Typical values are at V = +5V and T = +25°C.)
MAX CC A
CC
A
MIN
PARAMETER
WATCHDOG TIMER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
0.7V
CC
IH
WDI, WDS Input Threshold
WDI Pulse Width
V
V
IL
0.3V
CC
V
= 4.5V to 5.5V
30
60
CC
t
ns
WP
V
CC
= 2V to 4.5V
WDI, WDS Leakage Current
Extended mode disabled
±1
µA
µA
WDI Sink/Source Current
(Note 4)
Extended mode enabled
±70
WDS = GND, C
= 1500pF
2.8
1.4
4.0
2.0
5.2
2.6
ms
SWT
Watchdog Timeout Period
(Note 3)
t
WD
WDS = V , C
= 1500pF
SWT
sec
CC
Note 1: Reset is guaranteed valid from the selected reset threshold voltage down to the minimum V
.
CC
Note 2: VDS = V , WDI unconnected.
CC
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 (Figure 8). At V = 2V, it is typically ±24µA.
CC
CC
__________________________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s
(C
= C
= 1500pF, T = +25°C, unless otherwise noted.)
SRT A
SWT
NORMAL-MODE
EXTENDED-MODE
WATCHDOG TIMEOUT PERIOD vs. C
WATCHDOG TIMEOUT PERIOD vs. C
RESET TIMEOUT PERIOD
vs. C
SWT
SWT
(WDS = GND)
(WDS = V )
CC
SRT
10,000
10,000
10,000
V
CC
= 5V
V
CC
= 5V
V
CC
= 5V
1000
100
10
1000
100
10
1000
100
10
1
1
1
0.1
0
0
0.001 0.01
0.1
1
10
100 1000
0.001 0.01
0.1
1
10
100 1000
0.001 0.01
0.1
1
10
100 1000
C
SWT
(nF)
C
SWT
(nF)
C
SRT
(nF)
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
