MAX6832WXRD3-T Maxim Integrated, MAX6832WXRD3-T Datasheet - Page 7

• Manufacturer Part Number: MAX6832WXRD3-T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6832, MAX6833, MAX6834, MAX6835, MAX6836, MAX6837, MAX6838, MAX6839, MAX6840r

Specifications of MAX6832WXRD3-T

• Number Of Voltages Monitored: 1
• Monitored Voltage: 1.2 V to 1.8 V
• Undervoltage Threshold: 1.62 V
• Overvoltage Threshold: 1.71 V
• Output Type: Active Low, Push-Pull
• Manual Reset: Not Resettable
• Watchdog: No Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 210 ms
• Supply Voltage - Max: 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SC-70
• Chip Enable Signals: No
• Maximum Power Dissipation: 235 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 16 uA
• Supply Voltage - Min: 0.55 V

at RESET-IN allows for relatively large-value resistors to
be used, which reduce power consumption. For exam-
ple, for a 0.6V monitored trip level, if R2 = 200kΩ, then
R1 = 70.3kΩ. Note that the minimum V
required to guarantee the RESET-IN threshold accura-
cy (see Electrical Characteristics table).
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, the MAX6832–
MAX6840 are relatively immune to short-duration nega-
tive-going V
Figure 2 shows typical transient duration vs. reset com-
parator overdrive, for which the MAX6832–MAX6840 do
not generate a reset pulse. The graph was generated
using a negative-going pulse applied to V
0.1V above the actual reset threshold and ending
below it by the magnitude indicated (reset comparator
overdrive). The graph indicates the maximum pulse
width a negative-going V
causing a reset pulse. As the magnitude of the tran-
sient increases (goes farther below the reset threshold),
the maximum allowable pulse width decreases. A 0.1µF
bypass capacitor mounted as close as possible to the
V
When V
MAX6838 push-pull RESET output no longer sinks cur-
rent—it becomes an open circuit. Therefore, high-
impedance CMOS logic inputs connected to RESET
Figure 2. Maximum Transient Duration Without Causing a
Reset Pulse vs. Reset Comparator Overdrive
CC
pin provides additional transient immunity.
CC
900
800
700
600
500
400
300
200
100
0
falls below 0.55V, the MAX6832/MAX6835/
CC
Ultra-Low-Voltage SC70 Voltage Detectors
1
Negative-Going V
transients (glitches).
MAXIMUM TRANSIENT DURATION
Applications Information
Ensuring a Valid Reset Output
_______________________________________________________________________________________
OVERDRIVE V
vs. OVERDRIVE
CC
10
TH
transient can have without
RESET OCCURS
ABOVE THIS
LINE
- V
CC
(mV)
Down to V
CC
CC
Transients
100
CC
of 1.1V is
, starting
CC
= 0
can drift to undetermined voltages. This presents no
problem in most applications since most µP and other
circuitry are inoperative with V
However, in applications where RESET must be valid
down to 0, adding a pulldown resistor to RESET causes
any stray leakage currents to flow to ground, holding
RESET low (Figure 3). R3’s value is not critical; 100kΩ
is large enough not to load RESET and small enough to
pull RESET to ground.
A 100kΩ pullup resistor to V
for the MAX6833/MAX6836/MAX6839 if RESET is
required to remain valid for V
Since the RESET output on the MAX6834/MAX6837/
MAX6840 is open-drain, these devices interface easily
with µPs that have bidirectional reset pins. Connecting
the µP supervisor’s RESET output directly to the µP’s
RESET pin with a single pullup resistor allows either
device to assert a reset (Figure 4).
Figure 3.
Figure 4. Interfacing to µPs with Bidirectional Reset I/O
V
and µP Reset Circuits
CC
RESET Valid to V
Interfacing to µPs with Bidirectional
MAX6834
MAX6837
MAX6840
GND
V
CC
RESET
MAX6832
MAX6835
MAX6838
CC
= Ground Circuit
GND
V
CC
CC
RESET
CC
< 0.85V.
CC
is also recommended
RESET
INPUT
lower than 0.55V.
BIDIRECTIONAL
R3
100kΩ
Reset Pins
GND
V
µP
CC
7