MAX6746 Maxim, MAX6746 Datasheet - Page 11

• Manufacturer Part Number: MAX6746
• Description: UP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
• Manufacturer: Maxim

The open-drain RESET output can be used to interface
to a µP with other logic levels. As shown in
open-drain output can be connected to voltages from 0
to 6V.
Generally, the pullup resistor connected to the RESET
connects to the supply voltage that is being monitored
at the IC’s V
the open-drain output to level-shift from the monitored
supply to reset circuitry powered by some other supply.
Keep in mind that as the supervisor’s V
towards 1V, so does the IC’s ability to sink current at
RESET. Also, with any pullup resistor, RESET is pulled
high as V
this occurs depends on the pullup resistor value and
the voltage to which it is connected.
Figure 7. Ensuring RESET Valid to V
µP Reset Circuits with Capacitor-Adjustable
CC
CC
Interfacing to Other Voltages for
decays toward zero. The voltage where
pin. However, some systems can use
______________________________________________________________________________________
MAX6746
MAX6748
MAX6450
MAX6752
GND
RESET
V
CC
Logic Compatibility
CC
V
CC
= 0
100kΩ
Reset/Watchdog Timeout Delay
CC
Figure
decreases
6, the
When V
ities decline drastically. The high-impedance CMOS-
logic inputs connected to RESET can drift to undeter-
mined voltages. This presents no problems in most
applications, since most µPs and other circuitry do not
operate with V
In those applications where RESET must be valid down
to 0V, add a pulldown resistor between RESET and
GND for the MAX6746/MAX6748/MAX6750/MAX6752
push/pull outputs. The resistor sinks any stray leakage
currents, holding RESET low
pulldown resistor is not critical; 100kΩ is large enough
not to load RESET and small enough to pull RESET to
ground. The external pulldown can not be used with
the open-drain reset outputs.
Ensuring a Valid RESET Down to V
CC
falls below 1V, RESET current sinking capabil-
CC
below 1V.
(Figure
(Push-Pull RESET )
7). The value of the
CC
= 0V
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