- 您现在的位置：买卖IC网 > PDF目录14767 > MAX821MUS+T (Maxim Integrated Products)IC MONITOR VOLT MPU SOT143-4 PDF资料下载
参数资料
| 型号： | MAX821MUS+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 5/7页 |
| 文件大小： | 0K |
| 描述： | IC MONITOR VOLT MPU SOT143-4 |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 1 |
| 类型： | 简单复位/加电复位 |
| 监视电压数目： | 1 |
| 输出： | 推挽式，图腾柱 |
| 复位： | 低有效 |
| 复位超时： | 可调节/可选择 |
| 电压 - 阀值： | 4.38V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | TO-253-4，TO-253AA |
| 供应商设备封装： | SOT-143-4 |
| 包装： | 标准包装 |
| 产品目录页面： | 1413 (CN2011-ZH PDF) |
| 其它名称： | MAX821MUS+TDKR |
4-Pin μP Voltage Monitors with Pin-Selectable
Power-On Reset Timeout Delay
_______________Detailed Description
Reset Output
300
A microprocessor’s (μP’s) reset input starts the μP in a
known state. These μ P supervisory circuits assert reset
to prevent code-execution errors during power-up,
power-down, or brownout conditions. They also provide
a reset timeout delay that is pin programmable to 1ms
(max), 20ms (min), or 100ms (min). This feature allows
flexibility in designing bar-code scanners, hand-held
devices, and other applications that require quick or
nonstandard power-up times.
The MAX821’s RESET output is guaranteed to be a
250
200
150
100
50
T A = +25°C
logic low for V CC > 1V. Once V CC exceeds the reset
threshold, an internal timer keeps RESET low for the
0
1
10
100
1000
reset timeout period, as determined by the Set Reset
Timeout (SRT) input. See the Setting the Reset Timeout
Delay section.
If a brownout condition occurs (V CC dips below the
reset threshold), RESET goes low. Any time V CC goes
below the reset threshold, the internal timer resets to
zero, and RESET goes low. The internal timer begins
counting after V CC returns above the reset threshold,
and RESET remains low for the reset timeout period.
The MAX822 has an active-high RESET output that is
the inverse of the MAX821’s RESET output.
Setting the Reset Timeout Delay
Use the three-level Set Reset Timeout (SRT) input to set
the reset timeout delay. Connect SRT to GND for a 1ms
(max) delay; connect it to V CC for a 20ms (min) delay;
or leave it unconnected for a 100ms (min) delay.
If you choose to drive the SRT pin with an external sig-
nal, make sure the signal source can charge/discharge
the capacitance on SRT quickly enough (<500μs) to
avert an unintended reset timeout delay.
To ensure proper operation when selecting the 100ms
timeout (SRT = unconnected), minimize capacitive
loading on the SRT pin (< 200pF). Excessive capacitive
loading can select an unintended faster timeout mode.
Reset Threshold Accuracy
The MAX821/MAX822 are designed to meet their worst-
case specifications over their entire operating tempera-
ture range. Choose a reset threshold guaranteed to
assert at a voltage below the power supply’s regulation
range and above the minimum specified operating volt-
age range for the system’s ICs.
RESET COMPARATOR OVERDRIVE, V TH -V CC (mV)
Figure 1. Maximum Transient Duration Without Causing a
Reset Pulse vs. Comparator Overdrive
__________Applications Information
Negative-Going V CC Transients
While designed to issue a reset to the microprocessor
(μP) during power-up, power-down, and brownout con-
ditions, the MAX821/MAX822 are relatively immune to
short-duration, negative-going V CC transients (glitches).
Figure 1 shows the maximum transient duration vs. reset
comparator overdrive for which the MAX821/MAX822
typically do not generate a reset pulse. This graph was
generated using a negative-going pulse applied to V CC ,
starting above the actual reset threshold and ending
below it by the magnitude indicated (reset comparator
overdrive). The graph indicates the typical maximum
pulse width a negative-going V CC transient may have
without causing a reset pulse to be issued. As the mag-
nitude of the transient increases (goes farther below the
reset threshold), the maximum allowable pulse width
decreases. Typically, for the MAX821/MAX822, a V CC
transient that goes 100mV below the reset threshold and
lasts 12μs or less will not cause a reset pulse to be
issued. A 0.1μF capacitor mounted as close as possible
to V CC can provide additional transient immunity, if
desired.
_______________________________________________________________________________________
5
相关PDF资料 |
PDF描述 |
|---|---|
| MAX812TEUS+T | IC VOLT MON W/RESET SOT143-4 |
| IHLP2525AHERR10M01 | INDUCTOR POWER 0.1UH 18A SMD |
| IR3842MTR1PBF | IC REG BUCK SYNC ADJ 4A 15QFN |
| MAX812REUS+T | IC VOLT MON W/RESET SOT143-4 |
| LPX681M160C3P3 | CAP ALUM 680UF 160V 20% SNAP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX821PUS | 制造商:Maxim Integrated Products 功能描述:4-PIN UP VOLTAGE MONITORS WITH PIN- - Cut Tape Product 制造商:Rochester Electronics LLC 功能描述: |
| MAX821PUS+ | 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 4V 7UA 4PIN SOT-143 - Rail/Tube |
| MAX821PUS+T | 功能描述:监控电路 4-Pin uPower Voltage Monitor 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 |
| MAX821PUS-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 |
| MAX821RUS | 制造商:Maxim Integrated Products 功能描述:4-PIN UP VOLTAGE MONITORS WITH PIN- - Rail/Tube |
发布紧急采购，3分钟左右您将得到回复。