參數(shù)資料
型號: MAX821-MAX822
廠商: Maxim Integrated Products, Inc.
英文描述: 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
中文描述: 4引腳レP的電壓監(jiān)視器的引腳可選上電復(fù)位延遲時間
文件頁數(shù): 6/8頁
文件大?。?/td> 77K
代理商: MAX821-MAX822
M
Ensuring a V alid
RESET
Output
Down to V
CC
= 0V
When V
CC
falls below 1V, the MAX821
RESET
output
no longer sinks current—it becomes an open circuit.
Therefore, high-impedance CMOS logic inputs con-
nected to the
RESET
output can drift to undetermined
voltages. This presents no problem in most applica-
tions, since most
μ
P and other circuitry is inoperative
with V
CC
below 1V. However, in applications where the
RESET
output must be valid down to 0V, adding a pull-
down resistor to the
RESET
pin will cause any stray
leakage currents to flow to ground, holding
RESET
low
(Figure 2a). R1’s value is not critical; 100k
is large
enough not to load
RESET
, and small enough to pull
RESET
to ground.
A 100k
pull-up resistor to V
CC
is also recommended
for the MAX822 if RESET is required to remain valid for
V
CC
< 1V (Figure 2b).
Interfac ing to μPs with
Bidirec tional Reset Pins
μPs with bidirectional reset pins (such as the Motorola
68HC11 series) can contend with the MAX821 reset
output. For example, if the MAX821
RESET
output is
asserted high and the μP wants to pull it low, indetermi-
nate logic levels may result. To correct such cases,
connect a 4.7k
resistor between the MAX821
RESET
output and the μP reset I/O (Figure 3). Buffer the reset
output to other system components.
___________________Chip Information
TRANSISTOR COUNT: 492
4-Pin μP Voltage Monitors with Pin-S elec table
Power-On Reset T imeout Delay
6
_______________________________________________________________________________________
4.7k
V
CC
GND
RESET
MAX821
RESET
V
CC
GND
μ
P
BUFFER
BUFFERED RESET
TOOTHER SYSTEM
COMPONENTS
Figure 3. Interfacing to μPs with Bidirectional Reset I/O
R1
V
CC
V
CC
GND
MAX821
RESET
R1
V
CC
V
CC
GND
MAX822
RESET
a)
b)
Figure 2.
RESET/
RESET Valid to V
CC
= Ground Circuit
相關(guān)PDF資料
PDF描述
MAX821MUS-T 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
MAX821PUS-T 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
MAX821RUS-T 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
MAX821SUS-T 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
MAX821TUS-T 4-Pin レP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX821MUS 制造商:Maxim Integrated Products 功能描述:4-PIN UP VOLTAGE MONITORS WITH PIN- - Rail/Tube
MAX821MUS+ 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 4.38V 7UA 4PIN SOT-143 - Rail/Tube
MAX821MUS+T 功能描述:監(jiān)控電路 4-Pin uPower Voltage Monitor RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲(典型值):10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
MAX821MUST 制造商:MAXIM 功能描述:Pb Free
MAX821MUS-T 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲(典型值):10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel