DS1836CS-20+ Maxim Integrated Products, DS1836CS-20+ Datasheet - Page 3

• Manufacturer Part Number: DS1836CS-20+
• Description: IC MICROMAN 3.3V ACT LO 20%8SOIC
• Manufacturer: Maxim Integrated Products
• Series: MicroManagerr
• Type: Battery Backup Circuitr

Specifications of DS1836CS-20+

• Number Of Voltages Monitored: 1
• Output: Push-Pull, Totem Pole
• Reset: Active Low
• Reset Timeout: 200 ms Minimum
• Voltage - Threshold: 2.72V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS1836A/B/C/D
Non-Maskable Interrupt
The DS1836 generates a non-maskable interrupt (
) for early warning of a power failure. A precision
NMI
comparator monitors the voltage level at the IN pin relative to an on-chip reference generated by an
internal band gap. The IN pin is a high impedance input allowing for a user-defined sense point. An
external resistor voltage divider network (Figure 3) is used to interface with high voltage signals. This
sense point may be derived from a regulated supply or from a higher DC voltage level closer to the main
system power input. Since the IN trip point V
is 1.25V, the proper values for R1 and R2 can be
TP
determined by the equation as shown in Figure 3. Proper operation of the DS1836 requires that the
maximum voltage at the IN pin be limited to the active supply (V
or V
). Therefore, the maximum
CC
BAT
allowable voltage at the supply being monitored (V
) can also be derived as shown in Figure 3. A
MAX
simple approach to solving the equation is to select a value for R2 high enough to keep power
consumption low and solve for R1. The flexibility of the IN input pin allows for detection of power loss
at the earliest point in a power supply system, maximizing the amount of time for system shutdown
between
and RST (or
).
NMI
RST
A pull-up resistor is required for proper operation of the
open-drain output. A 10kΩ resistor would
NMI
be a typical value for the pull-up resistor.
TYPICAL APPLICATION Figure 2
3 of 9