MAX6802 MAXIM [Maxim Integrated Products], MAX6802 Datasheet - Page 4

• Manufacturer Part Number: MAX6802
• Description: 3-Pin, Low-Power uP Reset Circuits
• Manufacturer: MAXIM [Maxim Integrated Products]

3-Pin, Low-Power
µP Reset Circuits
Since the RESET output on the MAX6802 is open-drain,
this device interfaces easily with µPs that have bidirec-
tional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output directly
to the microcontroller’s (µC’s) RESET pin with a single
pullup resistor allows either device to assert reset
(Figure 1).
Figure 1. Interfacing to µPs with Bidirectional Reset Pins
4
_______________________________________________________________________________________
V
CC
Interfacing to µPs with Bidirectional
TOP VIEW
( ) ARE FOR MAX6800
MAX6802
RESET (RESET)
GND
V
CC
Applications Information
RESET
GND
1
2
Pin Configuration
SOT23-3
100kΩ
MAX6800
MAX6801
MAX6802
RESET
MOTOROLA
68HCXX
GND
V
3
μP
CC
Reset Pins
V
CC
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, these devices are
relatively immune to short-duration, negative-going V
transients (glitches). The Typical Operating Characteristics
show the Maximum Transient Duration vs. Reset
Comparator Overdrive graph. The graph shows the maxi-
mum pulse width that a negative-going V
typically have without issuing a reset signal. As the ampli-
tude of the transient increases, the maximum allowable
pulse width decreases.
Figure 2. Ensuring Reset Valid Down to V
(a)
V
CC
MAX6801
GND
V
CC
RESET
MAX6801
*ASSUMES HIGH-Z RESET INPUT TO THE μP
GND
Negative-Going V
V
Typical Operating Circuit
CC
RESET
100kΩ
(b)
RESET
MAX6800
CC
GND
CC
V
CC
= 0V
CC
GND
RESET
V
μP
CC
Transients
transient may
100kΩ*
CC