MAX6822VUK+T Maxim Integrated, MAX6822VUK+T Datasheet - Page 6
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MAX6822VUK+T
Manufacturer Part Number
MAX6822VUK+T
Description
Supervisory Circuits
Manufacturer
Maxim Integrated
Series
MAX6821, MAX6822, MAX6823, MAX6824, MAX6825r
Datasheet
1.MAX131CQHD.pdf
(11 pages)
Specifications of MAX6822VUK+T
Number Of Voltages Monitored
1
Monitored Voltage
1.8 V, 2.5 V, 3 V, 3.3 V, 5 V
Undervoltage Threshold
1.52 V
Overvoltage Threshold
1.62 V
Output Type
Active Low, Open Drain
Manual Reset
Resettable
Watchdog
Watchdog
Battery Backup Switching
No Backup
Power-up Reset Delay (typ)
320 ms
Supply Voltage - Max
5.5 V
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Package / Case
SOT-23
Chip Enable Signals
No
Maximum Power Dissipation
571 mW
Minimum Operating Temperature
- 40 C
Power Fail Detection
No
Supply Current (typ)
10 uA
Supply Voltage - Min
1 V
5-Pin, Multiple-Input,
Programmable Reset ICs
Figure 1. Functional Diagram
6
RST IN1
RST IN2
†††
***
††
**
MR
†
*
MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 ONLY
MAX6305–MAX6310 ONLY
MAX6311/MAX6312/MAX6313 ONLY
MAX6307/MAX6310/MAX6313 ONLY
MAX6305/MAX6308/MAX6311 ONLY
MAX6306/MAX6309/MAX6312 ONLY
+1.23V
+1.23V
V
CC
*
††
GND
MAX6305–MAX6313
†
+1.23V
GENERATOR
RESET
†††
V
CC
+1.23V
RESET**
RESET***
OVRST IN
open-drain, N-channel output. The MAX6308/MAX6309/
MAX6310 feature an active-low, complementary output
structure that both sinks and sources current, and the
MAX6311/MAX6312/MAX6313 have an active-high com-
plementary reset output.
The MAX6305/MAX6308/MAX6311 switch from under-
voltage lockout operation to normal operation between
1.5V < V
lockout mode asserts RESET. Above 2.5V, V
operation mode asserts reset if RST IN_ falls below the
RST IN_ threshold.
Many µP-based products require manual-reset capability,
allowing an operator or external logic circuitry to initiate a
reset. A logic low on MR asserts reset. Reset remains
asserted while MR is low, and for a reset active timeout
period (t
nal 63.5kΩ pull-up resistor, so it can be left open if it is not
used. MR can be driven with TTL-logic levels in 5V sys-
tems, with CMOS-logic levels in 3V systems, or with open-
drain/collector output devices. Connect a normally open
momentary switch from MR to GND to create a manual-
reset function; external debounce circuitry is not required.
If MR is driven from long cables or if the device is used in
a noisy environment, connecting a 0.1µF capacitor from
MR to ground provides additional noise immunity.
The MR pin has internal ESD-protection circuitry that may
be forward biased under certain conditions, drawing
excessive current. For example, assume the circuitry driv-
ing MR uses a +5V supply other than V
browns out lower than +4.7V, MR’s absolute maximum rat-
ing is violated (-0.3V to (V
current flows through the ESD structure from MR to V
To avoid this, it is recommended that the supply for the MR
pin be the same as the supply monitored by V
way, the voltage at MR will not exceed V
The MAX6305–MAX6313 each have one or more reset
inputs (RST IN_ /OVRST IN). These inputs are com-
pared to the internal reference voltage (Figure 1).
Connect a resistor voltage divider to RST IN_ such that
V
voltage (V
(V
with the following formula:
RST IN_
TH
) (Figure 2). Calculate the desired reset voltage
RP
falls below V
CC
) after MR returns high. This input has an inter-
IN
) falls below the desired reset threshold
< 2.5V. Below 1.5V, V
(MAX6306/MAX6309/MAX6312)
V
TH
= ________ x V
RSTH
R1 + R2
Adjustable Reset Inputs
R2
CC
(1.23V) when the monitored
+ 0.3V)), and undesirable
Manual-Reset Input
RSTH
CC
CC
CC
. If V
.
undervoltage-
CC
CC
CC
drops or
normal-
. In this
CC
.