MAX6836HXSD2-T Maxim Integrated, MAX6836HXSD2-T Datasheet - Page 7
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MAX6836HXSD2-T
Manufacturer Part Number
MAX6836HXSD2-T
Description
Supervisory Circuits
Manufacturer
Maxim Integrated
Series
MAX6832, MAX6833, MAX6834, MAX6835, MAX6836, MAX6837, MAX6838, MAX6839, MAX6840r
Datasheet
1.MAX6835VXSD0-T.pdf
(11 pages)
Specifications of MAX6836HXSD2-T
Number Of Voltages Monitored
1
Monitored Voltage
1.2 V to 1.8 V
Undervoltage Threshold
1.275 V
Overvoltage Threshold
1.35 V
Output Type
Active High, Push-Pull
Manual Reset
Resettable
Watchdog
No Watchdog
Battery Backup Switching
No Backup
Power-up Reset Delay (typ)
30 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
245 mW
Minimum Operating Temperature
- 40 C
Power Fail Detection
No
Supply Current (typ)
16 uA
Supply Voltage - Min
0.75 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