DS1815R-5-U+ Maxim Integrated, DS1815R-5-U+ Datasheet - Page 11

• Manufacturer Part Number: DS1815R-5-U+
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: DS1815r

Specifications of DS1815R-5-U+

• Number Of Voltages Monitored: 1
• Monitored Voltage: 0 V to 5.5 V
• Undervoltage Threshold: 2.98 V
• Overvoltage Threshold: 3.15 V
• Output Type: Active Low, Push-Pull
• Manual Reset: Not Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 250 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Chip Enable Signals: No
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: Yes
• Supply Current (typ): 35 uA
• Supply Voltage - Min: 0 V
• Part # Aliases: 90-1815R+U05

The open-drain RESET output can be used to interface
to a µP with other logic levels. As shown in Figure 6, the
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
= 0V
100kΩ
Reset/Watchdog Timeout Delay
CC
decreases
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 (Figure 7). The value of the
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.
(Push-Pull RESET )
CC
= 0V
11