參數(shù)資料
型號(hào): MAX807MCUE
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 電源管理
英文描述: Full-Featured uP Supervisory Circuit with +/-1.5% Reset Accuracy
中文描述: 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO16
封裝: TSSOP-16
文件頁(yè)數(shù): 10/16頁(yè)
文件大小: 196K
代理商: MAX807MCUE
M
Full-Featured μP Supervisory Circuit with
±1.5% Reset Accuracy
10
______________________________________________________________________________________
Watchdog Output
WDO remains high if there is a transition or pulse at
WDI during the watchdog-timeout period. WDO goes
low if no transition occurs at WDI during the watchdog-
timeout period. The watchdog function is disabled and
WDO is a logic high when V
CC
is below the reset
threshold or WDI is an open circuit. To generate a sys-
tem reset on every watchdog fault, diode-OR connect
WDO to MR (Figure 6). When a watchdog fault occurs
in this mode, WDO goes low, which pulls MR low, caus-
ing a reset pulse to be issued. As soon as reset is
asserted, the watchdog timer clears and WDO returns
high. With WDO connected to MR, a continuous high or
low on WDI will cause 200ms reset pulses to be issued
every 1.6s.
Chip-Enable Signal Gating
The MAX807 provides internal gating of chip-enable
(CE) signals to prevent erroneous data from corrupting
the CMOS RAM in the event of a power failure. During
normal operation, the CE gate is enabled and passes
all CE transitions. When reset is asserted, this path
becomes disabled, preventing erroneous data from
corrupting the CMOS RAM. The MAX807 uses a series
transmission gate from the Chip-Enable Input (CE IN) to
the Chip-Enable Output (CE OUT) (Figure 1).
The 8ns (max) chip-enable propagation from CE IN to
CE OUT enables the MAX807 to be used with most μPs.
Chip-Enable Input
CE IN is high impedance (disabled mode) while RESET
is asserted. During a power-down sequence when V
CC
passes the reset threshold, the CE transmission gate
disables and CE IN becomes high impedance 28μs
after reset is asserted (Figure 7). During a power-up
sequence, CE IN remains high impedance (regardless
of
CE
IN activity) until reset is deasserted following the
reset-timeout period.
In the high-impedance mode, the leakage currents into
this input are ±1μA (max) over temperature. In the low-
impedance mode, the impedance of CE IN appears as
a 75
resistor in series with the load at CE OUT.
The propagation delay through the CE transmission
gate depends on both the source impedance of the
drive to CE IN and the capacitive loading on CE OUT
MR
RESET
CE IN
0V
170ns
28
μ
s TYP
1
μ
s MIN
CE OUT
V
CC
V
RST
RESET
t
WD
WDO
WDI
WDO CONNECTED TO
μ
P INTERRUPT.
t
RP
Figure 4. Manual-Reset Timing Diagram
Figure 5. Watchdog Timing Relationship
V
CC
V
CC
RESET
WDO
WDO
4.7k
TO
μ
P
MR
RESET
WDI
t
RP
t
RP
t
WD
50
μ
s
MAX807
Figure 6. Generating a Reset on Each Watchdog Fault
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MAX807MCUE+ 功能描述:監(jiān)控電路 Full-Featured uPower Supervisor RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)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(kāi)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
MAX807MCUE+T 功能描述:監(jiān)控電路 Full-Featured uPower Supervisor RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)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(kāi)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
MAX807MCUE-T 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)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(kāi)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
MAX807MCWE 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)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(kāi)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
MAX807MCWE+ 功能描述:監(jiān)控電路 Full-Featured uPower Supervisor RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)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(kāi)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