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参数资料
| 型号： | MAX6454UT29S+T |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 电源管理 |
| 英文描述： | µP Supervisors with Separate VCC Reset and Manual Reset Outputs |
| 中文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| 封装： | LEAD FREE, SOT-23, 6 PIN |
| 文件页数： | 9/11页 |
| 文件大小： | 249K |
| 代理商： | MAX6454UT29S+T |
MAX6453–MAX6456
P Supervisors with Separate VCC Reset and
Manual Reset Outputs
_______________________________________________________________________________________
7
Applications Information
Interrupt Before Reset
To minimize data loss and speed system recovery/test,
many applications interrupt the processor or reset only
portions of the system before a processor hard reset is
asserted. The extended setup time of the MAX6455/
MAX6456 MR input allows the same pushbutton (Figure
4) to control both the interrupt and hard reset functions.
If the pushbutton is closed for less than the extended
setup timeout period, the processor is only interrupted
(MROUT). If the system still does not respond properly,
the pushbutton can be closed for the full extended
setup timeout period to hard reset the processor
(RESET). If desired, connect a LED to the RESET output
to turn off (or on) to signify when the pushbutton is
closed long enough for a hard reset (the same LED can
be used as the front panel power-on display).
Interfacing to Other Voltages
for Logic Compatibility
The open-drain RESET output can be used to interface
to a P with other logic levels. As shown in Figure 5, the
open-drain output can be connected to voltages from 0
to 6V.
Generally, the pullup resistor connected to the RESET
connects to the supply voltage being monitored at the
IC’s VCC pin. However, some systems might use the
open-drain output to level-shift from the monitored sup-
ply to reset circuitry powered by some other supply
(Figure 5). Keep in mind that as the supervisor’s VCC
decreases toward 1V, so does the IC’s ability to sink
current at RESET (RESET is pulled high as VCC decays
toward 0). The voltage where this occurs depends on
the pullup resistor value and the voltage to which it is
connected.
Ensuring a Valid
RESET Down to VCC = 0V
(Push-Pull
RESET)
When VCC falls below 1V, RESET current-sinking capa-
bilities decline drastically. The high-impedance CMOS-
logic inputs connected to RESET can drift to
undetermined voltages. This presents no problem in
most applications, because most Ps and other circuit-
ry do not operate with VCC below 1V.
In applications where RESET must be valid down to 0V,
add a pulldown resistor between RESET and GND for
the push/pull outputs. The resistor sinks any stray leak-
age currents, holding RESET low (Figure 6). The value
of the pulldown resistor is not critical; 100k
Ω is large
enough not to load RESET and small enough to pull
RESET to ground. The external pulldown cannot be
used with the open-drain reset outputs.
Transient Immunity
In addition to issuing a reset to the P during power-up,
power-down and brownout conditions, these supervisors
are relatively immune to short duration falling transients
(glitches). The graph Maximum Transient Duration vs.
Reset Threshold Overdrive in the Typical Operating
Characteristics section shows this relationship.
The area below the curves of the graph is the region in
which these devices typically do not generate a reset
pulse. This graph was generated using a negative
going pulse applied to VCC, starting above the actual
reset threshold (VTH) and ending below it by the magni-
tude indicated (reset-threshold overdrive). As the mag-
nitude of the transient increases (VCC goes further
below the reset threshold), the maximum allowable
pulse width decreases. Typically, a VCC transient that
goes 100mV below the reset threshold and lasts 20s
or less does not cause a reset pulse to be issued.
MAX6453
MAX6455
RSTIN
VCC
R1
R2
RESET
GND
VMON_TH = 0.63 x (R1 + R2) / R2
VMON_TH
VCC
Figure 3. Calculating The Monitored Threshold Voltages
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相关代理商/技术参数 |
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| MAX6454UT31S | 制造商:Maxim Integrated Products 功能描述:MICROPROCESSOR SUPERVISORS WITH SEP - Cut Tape Product |
| MAX6454UT31S+ | 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR ADJV 7UA 6PIN SOT-23 - Cut Tape Product |
| MAX6454UT31S+T | 功能描述:监控电路 Dual uPower Reset Circuit RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| MAX6454UT31S-T | 功能描述:监控电路 RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| MAX6454UT44S | 制造商:Maxim Integrated Products 功能描述:MICROPROCESSOR SUPERVISORS WITH SEP - Rail/Tube |
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