- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385551 > MAX811 (ON SEMICONDUCTOR) 4-Pin μP Reset Monitor(3腳μP監(jiān)控電路復位監(jiān)視器（低電平復位）) PDF資料下載
參數(shù)資料
| 型號： | MAX811 |
| 廠商： | ON SEMICONDUCTOR |
| 英文描述： | 4-Pin μP Reset Monitor(3腳μP監(jiān)控電路復位監(jiān)視器（低電平復位）) |
| 中文描述： | 4引腳微處理器電壓監(jiān)視器，帶有手動復位輸入 |
| 文件頁數(shù)： | 4/8頁 |
| 文件大?。?/td> | 52K |
| 代理商： | MAX811 |
MAX811, MAX812
http://onsemi.com
4
APPLICATIONS INFORMATION
V
CC
Transient Rejection
The MAX811/12 provides accurate V
CC
monitoring and
reset timing during power–up, power–down, and
brownout/sag conditions, and rejects negative–going
transients (glitches) on the power supply line. Figure 1
shows the maximum transient duration vs. maximum
negative excursion (overdrive) for glitch rejection. Any
combination of duration and overdrive that lays
under
the
curve will
not
generate a reset signal. Combinations above
the curve are detected as a brownout or power–down.
Transient immunity can be improved by adding a capacitor
in close proximity to the V
CC
pin of the MAX811/12.
Figure 1. Maximum Transient Duration vs.
Overdrive for Glitch Rejection at 25
°
C
M
Reset Comparator Overdrive, [V
CCTP
–V
CC
](mV)
400
320
240
160
80
0
T
A
= +25
°
C
1
5
100
1000
MAX811/12
Duration
V
CC
V
TH
Overdrive
RESET Signal Integrity During Power–Down
The MAX811 RESET output is valid to V
CC
= 1.0 V.
Below this voltage the output becomes an “open circuit’’ and
does not sink current. This means CMOS logic inputs to the
μ
P will be floating at an undetermined voltage. Most digital
systems are completely shutdown well above this voltage.
However, in situations where RESET must be maintained
valid to V
CC
= 0 V, a pull–down resistor must be connected
from RESET to ground to discharge stray capacitances and
hold the output low (Figure 2). This resistor value, though
not critical, should be chosen such that it does not
appreciably load RESET under normal operation (100 k
will be suitable for most applications). Similarly, a pull–up
resistor to V
CC
is required for the MAX812 to ensure a valid
high RESET for V
CC
below 1.1 V.
Figure 2. Ensuring RESET Valid to V
CC
= 0 V
VCC
GND
VCC
MAX811
RESET
R1
100 K
Processors with Bidirectional I/O Pins
Some
μ
P’s (such as Motorola’s 68HC11) have
bi–directional reset pins. Depending on the current drive
capability of the processor pin, an indeterminate logic level
may result if there is a logic conflict. This can be avoided by
adding a 4.7 k
resistor in series with the output of the
MAX811/12 (Figure 3). If there are other components in the
system which require a reset signal, they should be buffered
so as not to load the reset line. If the other components are
required to follow the reset I/O of the
μ
P, the buffer should
be connected as shown with the solid line.
Figure 3. Interfacing to Bidirectional Reset I/O
GND
MAX811
VCC
RESET
VCC
RESET
GND
VCC
BUFFER
4.7 K
P
BUFFERED
RESET TO
OTHER
SYSTEM
COMPONENTS
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX812 | 4-Pin μP Reset Monitor(3腳μP監(jiān)控電路復位監(jiān)視器（高電平復位）) |
| MAX812_EUS-T | 4-Pin レP Voltage Monitors with Manual Reset Input |
| MAX812 | 4-Pin μp Voltage Monitors with Manual Reset Input(4管腳μP電壓監(jiān)控器,低有效復位輸出) |
| MAX814 | Accuracy, Low-Power, +3V and +5V μp Supervisory Circuits(高精度，±1%，低功耗，3V和5VμP監(jiān)控電路) |
| MAX818 | Microprocessor Supervisory Circuits(5VμP監(jiān)控電路,斷電警告) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX811/D | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:4-Pin mP Reset Monitors |
| MAX811_EUS-T | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:4-Pin μP Voltage Monitors with Manual Reset Input |
| MAX811CUS-T | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Analog IC |
| MAX811LCUS-T | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Voltage Detector |
| MAX811LEUS | 制造商:Maxim Integrated Products 功能描述:4-PIN UP VOLTAGE MONITORS WITH MANU - Rail/Tube |
發(fā)布緊急采購，3分鐘左右您將得到回復。