參數(shù)資料
型號: MAX6373KA-T
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 電源管理
英文描述: Pin-Selectable Watchdog Timers
中文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封裝: SOT-23, 8 PIN
文件頁數(shù): 7/8頁
文件大?。?/td> 114K
代理商: MAX6373KA-T
completion of the startup delay period, and no watch-
dog output pulses are asserted during the startup
delay. When the startup delay expires, the watchdog
begins counting its normal watchdog timeout period
and waiting for WDI transitions. The startup delay
allows time for the μP system to power up and fully ini-
tialize before assuming responsibility for the normal
watchdog timer updates. Startup delay periods vary
between the different devices and may be altered by
the logic control set pins. To ensure that the system
generates no undesired watchdog outputs, the routine
watchdog input transitions should begin before the
selected minimum startup delay period has expired.
The normal watchdog timeout period countdown is initi-
ated when the startup delay is complete. If a valid logic
transition is not recognized at WDI before the watchdog
timeout period has expired, the supervisor asserts a
watchdog output. Watchdog timeout periods vary
between the different devices and may be altered by
the logic control set pins. To ensure that the system
generates no undesired watchdog outputs, the watch-
dog input transitions should occur before the selected
minimum watchdog timeout period has expired.
The startup delay and the watchdog timeout period are
determined by the states of the SET0, SET1, and SET2
pins, and by the particular device within the family. For
the MAX6369 and MAX6370, the startup delay is equal
to the watchdog timeout period. The startup and
watchdog timeout periods are pin selectable from 1ms
to 60s (minimum).
For the MAX6371 and MAX6372, the startup delay is
fixed at 60s and the watchdog timeout period is pin
selectable from 1ms to 60s (minimum).
The MAX6373/MAX6374 provide two timing variations
for the startup delay and normal watchdog timeout.
Five of the pin-selectable modes provide startup delays
from 200μs to 60s minimum, and watchdog timeout
delays from 3ms to 10s minimum. Two of the selectable
modes do not initiate the watchdog timer until the
device receives its first valid watchdog input transition
(there is no fixed period by which the first input must be
received). These two extended startup delay modes
are useful for applications requiring more than 60s for
system initialization.
All the MAX6369
MAX6374 devices may be disabled
with the proper logic control pin setting (Table 1).
Applications Information
Input Signal Considerations
Watchdog timing is measured from the last WDI rising
or falling edge associated with a pulse of at least 100ns
in width. WDI transitions are ignored when
WDO
is
asserted, and during the startup delay period (Figure
2). Watchdog input transitions are also ignored for a
setup period, t
SETUP
, of up to 300μs after power-up or
a setting change (Figure 3).
Selecting Device Timing
SET2, SET1, and SET0 program the startup delay and
watchdog timeout periods (Table 1). Timeout settings
can be hard wired, or they can be controlled with logic
gates and modified during operation. To ensure smooth
transitions, the system should strobe WDI immediately
before the timing settings are changed. This minimizes
the risk of initializing a setting change too late in the
timer countdown period and generating undesired
watchdog outputs. After changing the timing settings,
two outcomes are possible based on
WDO
. If the
change is made while
WDO
is asserted, the previous
setting is allowed to finish, the characteristics of the
new setting are assumed, and the new startup phase is
entered after a 300μs setup time (t
SETUP
) elapses. If
the change is made while
WDO
is not asserted, the
new setting is initiated immediately, and the new start-
up phase is entered after the 300μs setup time elapses.
M
Pin-Selectable Watchdog Timers
_______________________________________________________________________________________
7
t
WD
t
WD
t
WD
t
SETUP
t
DELAY
t
WD
t
SETUP
t
DELAY
t
WD
*
*
*
*
*
*IGNORED EDGE
WDI
WDO
SET_
Figure 3. Setting Change Timing
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相關代理商/技術參數(shù)
參數(shù)描述
MAX6374KA 制造商:Maxim Integrated Products 功能描述:8-SOT_ - Rail/Tube
MAX6374KA/V+T 功能描述:計時器和支持產(chǎn)品 Pin-Selectable Watchdog Timer RoHS:否 制造商:Micrel 類型:Standard 封裝 / 箱體:SOT-23 內(nèi)部定時器數(shù)量:1 電源電壓-最大:18 V 電源電壓-最小:2.7 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Reel
MAX6374KA+ 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 8UA 8PIN SOT-23 - Rail/Tube
MAX6374KA+T 功能描述:監(jiān)控電路 Pin-Selectable Watchdog Timer 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 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲(典型值):10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
MAX6374KA-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 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲(典型值):10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel