參數(shù)資料
型號: MAX704
廠商: Maxim Integrated Products, Inc.
英文描述: 3.0V/3.3V Microprocessor Supervisory Circuits(支持備用電池復位器,復位門限4.40V)
中文描述: 低成本微處理器監(jiān)控電路,具有備用電池控制器
文件頁數(shù): 7/12頁
文件大小: 134K
代理商: MAX704
Watc hdog Input
(MAX 690_/802_/804_/805_)
The watchdog circuit monitors the μP’s activity. If the μP
does not toggle the watchdog input (WDI) within 1.6sec,
a reset pulse is triggered. The internal 1.6sec timer is
cleared by either a reset pulse or by a transition (low-to-
high or high-to-low) at WDI. If WDI is tied high or low, a
WD
plus t
RS
).
As long as reset is asserted, the timer remains cleared
and does not count. As soon as reset is deasserted,
the timer starts counting. Unlike the 5V MAX690 family,
the watchdog function
cannot
be disabled.
Power-Fail Comparator
The PFI input is com,–——O goes low. The power-fail
PFI is less than V
comparator is intended for use as an undervoltage
detector to signal a failing power supply. However, the
comparator does not need to be dedicated to this
function because it is completely separate from the rest
of the circuitry.
The power-fail comparator turns off and–——O goes low
when V
falls below V
on power-down. The power-
fail comparator turns on as V
crosses V
on
power-up. If the comparator is not used, connect PFI to
connected to–M—–on the MAX704_/MAX806_ so that a
low voltage on PFI will generate a reset (Figure 5b).
M
3.0V /3.3V Mic roproc essor S upervisory Circ uits
_______________________________________________________________________________________
7
V
BATT
RESET
(RESET)
WDI
V
CC
MR
BATTERY
SWITCHOVER
COMPARATOR
RESET
COMPARATOR
RESET
GENERATOR
WATCHDOG
TIMER
BATTERY
SWITCHOVER
CIRCUITRY
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
PFO
V
OUT
PFI
V
PFT
1.237V
1.237V
**
*
*
POWER-FAIL
COMPARATOR
* MAX690T/S/R, MAX802T/S/R, MAX804T/S/R, MAX805T/S/R ONLY
** MAX704T/S/R, MAX806T/S/R ONLY
( ) MAX804T/S/R, MAX805T/S/R ONLY
V
BATT
= 3.6V
3.0V OR 3.3V
V
SW
t
WP
RESET
PFO
V
CC
( ) MAX804T/S/R, MAX805T/S/R ONLY, RESET EXTERNALLY PULLED UP TOV
CC
V
OUT
V
SW
(RESET)
3.0V OR 3.3V
3.0V OR 3.3V
0V
V
RST
V
BATT
= PFI = 3.6V
I
OUT
= 0mA
Figure 1. Block Diagram
Figure 2. Timing Diagram
相關PDF資料
PDF描述
MAX804 3.0V/3.3V Microprocessor Supervisory Circuits(具有看門狗和支持備用電池,3V高精度復位器(高電壓復位))
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相關代理商/技術參數(shù)
參數(shù)描述
MAX704_C/D 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:3.0V/3.3V Microprocessor Supervisory Circuits
MAX704_CPA 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:3.0V/3.3V Microprocessor Supervisory Circuits
MAX704_CSA 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:3.0V/3.3V Microprocessor Supervisory Circuits
MAX704_EPA 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:3.0V/3.3V Microprocessor Supervisory Circuits
MAX704_ESA 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:3.0V/3.3V Microprocessor Supervisory Circuits