45
44
43
42
41
40
39
38
37
36
35
45
44
43
42
41
40
39
38
37
36
35
4.75V
5.0V
5.5V
-40C
25C
+85C
-40C
25C
+85C
4.75V
5.0V
5.5V
Centigrade Temperature
VCC
Figure 20. Supply Current vs. Temperature
Figure 21. Supply Current vs. Supply Voltage
UnliketheDS1232,theSP705-708/813L
Applications
series has a separate watchdog output pin WDO
which can be simply connected to the MR input
to generate a Reset signal. The DS1232 has pin
selectable features, while the SP705-708/813L
series has more fixed functions of reset
threshold and watchdog time-out delay. For
most applications, the fixed functions will be
preferred, with the benefit of reduced cost due to
a less complex part. In addition, the SP705-708/
813L series has a power fail input and
output function not available with the DS1232
that is useful for monitoring systems with
unregulated supply voltages. The SP705-708/
813L series is available in one of the
industry's smallest space-saving package sizes,
the µSOIC.
The SP705-708/813L series offers
unmatched performance and the lowest power
consumptionfortheseindustrystandarddevices.
Refer to Figures 20 and 21 for supply current
performance characteristics rated against
temperature and supply voltages.
Table 2 shows how the SP705-708/813L
series can be used instead of the Dallas
Semiconductor DS1232LP/LPS. Table 2
illustratestoadesignertheadvantagesandtrade-
offs of the SP705-708/813L series
compared to the Dallas Semiconductor device.
While the names of the pin descriptions may
differ, the functions are the same or very similar.
June 2008 Rev C
SP705 Low Power Microprocessor Supervisory Circuits
© 2008 Exar Corporation
13
EXAR [ EXAR CORPORATION ]
