MAX6302 Maxim, MAX6302 Datasheet - Page 5

• Manufacturer Part Number: MAX6302
• Description: +5V / Low-Power uP Supervisory Circuits with Adjustable Reset/Watchdog
• Manufacturer: Maxim

______________________________________________________________Pin Description
PIN
1
2
3
4
5
6
7
8
(MAX6301/3)
(MAX6302/4)
RESET IN
NAME
RESET
RESET
GND
WDS
SWT
SRT
WDI
V
CC
_______________________________________________________________________________________
+5V, Low-Power µP Supervisory Circuits
Reset Input. High-impedance input to the reset comparator. Connect this pin to the center point of an
external resistor voltage-divider network to set the reset threshold voltage. The reset threshold voltage
is calculated as follows: V
Ground
Set Reset-Timeout Input. Connect a capacitor between this input and ground to select the reset timeout
period (t
Typical Operating Circuit ).
Set Watchdog-Timeout Input. Connect a capacitor between this input and ground to select the basic
watchdog timeout period (t
and t
Watchdog-Select Input. This input selects the watchdog mode. Connect to ground to select normal mode
and the basic watchdog timeout period. Connect to V
timeout period by a factor of 500. A change in the state of this pin resets the watchdog timer to zero.
Watchdog Input. A rising or falling transition must occur on this input within the selected watchdog
timeout period, or a reset pulse will occur. The capacitor value selected for SWT and the state of WDS
determine the watchdog timeout period. The watchdog timer clears and restarts when a transition
occurs on WDI or WDS. The watchdog timer is cleared when reset is asserted and restarted after reset
deasserts. In the extended watchdog mode (WDS = V
driving WDI with a three-stated driver or by leaving WDI unconnected.
Open-Drain, Active-Low Reset
Output (MAX6301)
Push/Pull, Active-Low Reset
Output (MAX6303)
Open-Drain, Active-High Reset
Output (MAX6302)
Push/Pull, Active-High Reset
Output (MAX6304)
Supply Voltage
WD
RS
in µs. The watchdog function can be disabled by connecting this pin to ground.
). Determine the period as follows: t
with Adjustable Reset/Watchdog
RST
WD
). Determine the period as follows: t
= 1.22 x (R1 + R2) / R2 (see Typical Operating Circuit ).
RESET changes from high to low whenever the monitored voltage
(V
remains low as long as V
RESET remains low for the reset timeout period and then goes high.
The watchdog timer triggers a reset pulse (t
dog timeout period (t
RESET changes from low to high whenever the monitored voltage
(V
remains high as long as V
RESET remains high for the reset timeout period and then goes low.
The watchdog timer triggers a reset pulse (t
dog timeout period (t
IN
IN
) drops below the selected reset threshold (V
) drops below the selected reset threshold (V
FUNCTION
RP
= 2.67 x C
CC
CC
to select extended mode, multiplying the basic
WD
WD
), the watchdog function can be disabled by
) is exceeded.
) is exceeded.
IN
SRT
IN
is below V
is below V
, with C
WD
= 2.67 x C
SRT
RST
RST
in pF and t
. Once V
. Once V
RP
RP
SWT
) whenever the watch-
) whenever the watch-
RST
RST
, with C
IN
IN
RP
exceeds V
). RESET
). RESET
exceeds V
in µs (see
SWT
in pF
RST
RST
,
,
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