参数资料
型号: MAX696CPE+
厂商: Maxim Integrated Products
文件页数: 10/15页
文件大小: 0K
描述: IC MPU SUPERVISORY CIRCUIT 16DIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 25
类型: 多压监控器
监视电压数目: 2
输出: 推挽式,推挽式
复位: 高有效/低有效
复位超时: 最小为 35 ms
电压 - 阀值: 可调节/可选择
工作温度: 0°C ~ 70°C
安装类型: 通孔
封装/外壳: 16-DIP(0.300",7.62mm)
供应商设备封装: 16-PDIP
包装: 管件
Microprocessor Supervisory Circuits
LL IN
RESET
1.3V
50ms
1.312V
1.3V
50ms
1.312V
OUTPUT
LOW LINE
OUTPUT
(MAX697) CE IN
(MAX697) CE OUT
Figure 5. MAX697 Reset Timing
CE Gating and
RAM Write Protection
The MAX697 uses two pins to control the CE or WRITE
inputs of CMOS RAMs. When LL IN is > 1.3V, CE OUT is
a buffered replica of CE IN, with a 50ns propagation
delay. If LL IN input falls below 1.3V (1.2V min, 1.4V
max), an internal gate forces CE OUT high, indepen-
dent of CE IN. The CE output is also forced high when
V CC is less than V BATT . (See Figure 4.)
CE OUT typically drives the CE , CS , or WRITE input of
battery backed up CMOS RAM. This ensures the
integrity of the data in memory by preventing write
operations when V CC is at an invalid level. Similar pro-
tection of EEPROMs can be achieved by using the CE
OUT to drive the STORE or WRITE inputs of an EEP-
ROM, EAROM, or NOVRAM.
If the 50ns typical propagation delay of CE OUT is too
long, connect CE IN to GND and use the resulting CE
OUT to control a high-speed external logic gate. A sec-
ond alternative is to AND the LOW LINE output with the
CE or WR signal. An external logic gate and the RESET
output of the MAX696/MAX697 can also be used for
CMOS RAM write protection.
1.25V Comparator and Power-Fail Warning
The power-fail input (PFI) is compared to an internal
1.3V reference. The power-fail output ( PFO ) goes low
when the voltage at PFI is less than 1.3V. Typically PFI
is driven bay an external voltage-divider that senses
either the unregulated DC input to the system’s V CC
regulator or the regulated output. The voltage-divider
ration can be chosen so the voltage at PFI falls below
1.3V several milliseconds before the LL IN falls below
1.3V. PFO is normally used to interrupt the micro-
processor so that data can be stored in RAM before
LL IN falls below 1.3V and the RESET output goes low.
The power-fail detector can also monitor the backup
battery to warn of a low-battery condition. To conserve
battery power, the power-fail detector comparator is
turned off and PFO is forced low when V CC is lower
than the V BATT input voltage.
Watchdog Timer and Oscillator
The watchdog circuit monitors the activity of the micro-
processor. If the microprocessor does not toggle the
watchdog input (WDI) within the selected timeout period,
a 50ms RESET pulse is generated. Since many systems
cannot service the watchdog timer immediately after a
reset, the MAX696/MAX697 have a longer timeout period
after a reset is issued. The normal timeout period
10
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相关代理商/技术参数
参数描述
MAX696CPE+ 功能描述:监控电路 MPU Supervisor 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
MAX696CWE 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
MAX696CWE+ 功能描述:监控电路 MPU Supervisor 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
MAX696CWE+T 功能描述:监控电路 MPU Supervisor 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
MAX696CWE-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