MAX6344_UT-T View Datasheet(PDF) - Maxim Integrated
Part Name
Description
Manufacturer
MAX6344_UT-T Datasheet PDF : 8 Pages
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6-Pin µP Reset Circuit with
Power-Fail Comparator
MAX6342
PIN
MAX6343 MAX6344
MAX6345
5
5
5
—
6
6
—
5
—
—
6
6
NAME
MR
RESET
RESET
Pin Description (continued)
FUNCTION
Manual-Reset Input. Pull low to force a reset. RESET or RESET
remains active as long as MR is low and for the reset timeout
period after MR goes high. Leave unconnected or connect to
VCC if unused.
Active-Low Reset Output. Push-pull for MAX6342/MAX6345.
Open-drain for MAX6343. It remains low for 180ms after VCC
rises above the reset threshold or MR goes from low to high.
Active-High Push-Pull Reset Output. It remains high for 180ms
after VCC rises above the reset threshold or MR goes from low
to high.
1 VCC
VTH
2
GND
3
PFI
1.25V
RESET
GENERATOR
6
RESET
VCC (RESET)
MAX6342
MAX6343
MAX6344
100kΩ
5
MR
4
PFO
( ) ARE FOR MAX6344 ONLY.
Figure 1. MAX6342/MAX6343/MAX6344 Functional Diagram
1 VCC
VTH
2
GND
3
PFI
1.25V
RESET
GENERATOR
RESET 6
MAX6345
RESET 5
PFO 4
Figure 2. MAX6345 Functional Diagram
_______________Detailed Description
Reset Output
A µP’s reset input starts the µP in a known state. These
µP supervisory circuits assert reset to prevent code-
execution errors during power-up, power-down, or
brownout conditions.
RESET and RESET are guaranteed to be asserted at a
valid logic level for VCC > +1V (see the Electrical Char-
acteristics table). Once RESET asserts, it remains
asserted for at least 100ms (tRP) after VCC rises above
its threshold value or after MR returns high (Figures 1
and 2).
Open-Drain RESET Output
The MAX6343 has an active-low, open-drain reset out-
put. This output sinks current when RESET is asserted.
Connect a pull-up resistor from RESET to any positive
supply voltage up to +5.5V (Figure 3). Select a resistor
value large enough to register a logic low (see the Elec-
trical Characteristics table), and small enough to regis-
ter a logic high while supplying all input current and
leakage paths connected to the RESET line. A 10kΩ
pull-up is sufficient in most applications.
Manual Reset
The MAX6342/MAX6343/MAX6344s’ manual-reset input
(MR) allows reset to be triggered by a pushbutton
switch. The switch is effectively debounced by the 1µs
min reset pulse width. MR is CMOS-logic compatible.
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