參數(shù)資料
型號: MAX6842DUKD3
廠商: Maxim Integrated Products, Inc.
英文描述: Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
中文描述: 超低電壓復(fù)位電路和電壓檢測器
文件頁數(shù): 6/9頁
文件大?。?/td> 185K
代理商: MAX6842DUKD3
M
RESET IN decreases. The MAX6843/MAX6844/
MAX6845 assert a reset when the voltage at RESET IN
falls below the RESET IN threshold (V
RSTIN
). The low-
leakage current at RESET IN allows for relatively large-
value resistors to be used, which reduces power
consumption. For example, for V
CC-TH
= 0.9V, if R2 =
100k
, then R1 = 26.3k
.
Applications Information
V
CC
Falling Transients
The MAX6841
MAX6845 are relatively immune to short-
duration falling V
CC
transients (glitches). Figure 2
shows typical transient duration vs. reset comparator
overdrive, for which the MAX6841
MAX6845 do not
generate a reset pulse. The graph was generated using
a falling pulse applied to V
CC
, starting 0.1V above the
actual reset threshold and ending below it by the mag-
nitude indicated (reset comparator overdrive). The
graph indicates the maximum pulse width that a falling
V
CC
transient can have without causing a reset pulse.
As the magnitude of the transient increases (goes fur-
ther below the reset threshold), the maximum allowable
pulse width decreases. A 0.1μF bypass capacitor
mounted as close as possible to the V
CC
pin provides
additional transient immunity.
Ensuring a Valid Reset Output
Down to V
CC
= 0
When V
CC
falls below 0.55V, the MAX6841/MAX6843
push-pull
RESET
output no longer sinks current; it
becomes an open circuit. Therefore, high-impedance
CMOS-logic inputs connected to
RESET
can drift to
undetermined voltages. This presents no problem in
most applications, because most μP and other circuitry
are inoperative with V
CC
lower than 0.55V. However, in
applications in which
RESET
must be valid down to 0,
adding a pulldown resistor to
RESET
causes any stray
leakage currents to flow to ground, holding
RESET
low
(Figure 3). R3
s value is not critical; 200k
is large
enough not to load
RESET
and small enough to pull
RESET
to ground.
A 200k
pullup resistor to V
CC
is also recommended
for the MAX6841/MAX6842/MAX6844 if push-pull
RESET is required to remain valid for V
CC
0.75V.
Interfacing to μPs with Bidirectional
Reset Pins
Because the
RESET
output on the MAX6842/MAX6845
is open drain, these devices interface easily with μPs
that have bidirectional reset pins. Connecting the μP
supervisor
s
RESET
output directly to the μP
s
RESET
pin with a single pullup resistor allows either device to
assert reset (Figure 4).
Ultra-Low-Voltage μP Reset Circuits and
Voltage Detectors
6
_______________________________________________________________________________________
MAXIMUM TRANSIENT DURATION
vs. OVERDRIVE
OVERDRIVE V
TH
- V
CC
(mV)
M
μ
s
10
150
200
250
300
350
400
450
500
550
600
100
1
100
RESET OCCURS ABOVE THIS LINE
Figure 2. Maximum Transient Duration vs. Overdrive
MAX6841
MAX6843
V
CC
RESET
GND
R3
Figure 3.
RESET
Valid to V
CC
= 0
MAX6842
MAX6845
V
CC
V
CC
RESET
GND
V
CC
RESET
INPUT
GND
μ
P
Figure 4. Interfacing to Microprocessors with Bidirectional
Reset I/0
相關(guān)PDF資料
PDF描述
MAX6842FUKD0 Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
MAX6842FUKD3 Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
MAX6842HUKD0 Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
MAX6841DUKD0 Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
MAX6841DUKD3 Ultra-Low-Voltage uP Reset Circuits and Voltage Detectors
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX6842DUKD3+ 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 0.788V 8.1UA 5PIN SOT-23 - Cut Tape Product
MAX6842DUKD3+T 功能描述:監(jiān)控電路 Single uPower Reset Circuit 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
MAX6842DUKD3-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
MAX6842DUKD4 制造商:Maxim Integrated Products 功能描述:- Rail/Tube
MAX6842DUKD4+ 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 0.788V 8.1UA 5PIN SOT-23 - Rail/Tube