MCP100 Microchip Technology, MCP100 Datasheet - Page 3

• Manufacturer Part Number: MCP100
• Description: Microcontroller Supervisory Circuit with Push-Pull Output
• Manufacturer: Microchip Technology

FIGURE 1-1: MCP100/101 Timing Diagram
2.0
2.1
For many of today’s microcontroller applications, care
must be taken to prevent low power conditions that can
cause many different system problems. The most com-
mon causes are brown-out conditions where the sys-
tem
momentarily, and the second, is when a slowly decay-
ing power supply causes the microcontroller to begin
executing instructions without enough voltage to sus-
tain SRAM and producing indeterminate results.
FIGURE 2-1: Typical Application
2.2
Many system designers implementing POR circuits are
concerned about the minimum pulse width required to
cause a reset. Figure 2-2 shows typical transient dura-
tion vs. reset comparator overdrive for which the
MCP100/101 will not generate a reset pulse. It shows
that the farther below the trip point the transient pulse
goes, the duration of the pulse required to cause a
reset gets shorter. A 0.1 µF bypass cap mounted as
close as possible to the V
transient immunity.
1999 Microchip Technology Inc.
V
SS
supply
MCP100
APPLICATIONS INFORMATION
The Need for Supervisory Circuits
Negative Going V
RST
V
DD
drops
V
DD
capacitor
bypass
V
RESET
(MCP100)
RESET
(MCP101)
DD
below
DD
MICROCONTROLLER
DD
V
pin provides additional
RESET
MCLR
the
DD
OR
Transients
V SS
V
operating
TRIP
t
RPU
level
Preliminary
V
V
OH
OL
FIGURE 2-2: Typical Transient Response
5V
0
0
10
T
D
RANSIENT
8
6
4
2
0
URATION
0
Transients below
the curve will NOT
cause a reset
1
Transients above the
curve will cause a reset
MCP100/101
V
OL
t
TIME
V
RPD
2
TRIP
(V
- V
TRIP
DD
3
T
(V)
MIN
A
= +25°C
-
V
DS11187D-page 3
DD
4
)
V
V
TRIP
TRIP
MAX
MIN
5