参数资料
型号: MAX6302CPA+
厂商: Maxim Integrated Products
文件页数: 10/12页
文件大小: 0K
描述: IC SUPERVISOR MPU 8-DIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 50
类型: 简单复位/加电复位
监视电压数目: 1
输出: 开路漏极或开路集电极
复位: 高有效
复位超时: 最小为 2.8 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: 8-DIP(0.300",7.62mm)
供应商设备封装: 8-PDIP
包装: 管件
+5V, Low-Power μP Supervisory Circuits
with Adjustable Reset/Watchdog
V CC
V CC
MAX6303
V CC
MAX6304
V CC
100k ?
RESET
0.1 μ F
RESET
0.1 μ F
GND
100k ?
GND
Figure 9. Ensuring RESET Valid to V CC = 0V
In those applications where RESET must be valid down
to 0V, adding a pulldown resistor between RESET and
ground sinks any stray leakage currents, holding
RESET low (Figure 9). The value of the pulldown resistor
is not critical; 100k ? is large enough not to load RESET
and small enough to pull RESET to ground. For applica-
tions using the MAX6304, a 100k ? pullup resistor
between RESET and V CC will hold RESET high when
V CC falls below 1V (Figure 10).
Watchdog-Software Considerations
To help the watchdog timer monitor software execution
more closely, set and reset the watchdog input at differ-
ent points in the program, rather than pulsing the
watchdog input high-low-high or low-high-low. This
technique avoids a stuck loop in which the watchdog
timer would continue to be reset within the loop, keeping
the watchdog from timing out.
Figure 11 shows an example of a flow diagram where
the I/O driving the watchdog input is set high at the
beginning of the program, set low at the beginning of
every subroutine or loop, then set high again when the
program returns to the beginning. If the program should
hang in any subroutine the problem would quickly be
corrected, since the I/O is continually set low and the
watchdog timer is allowed to time out, causing a reset
or interrupt to be issued. When using extended mode,
as described in the Watchdog Input Current section,
this scheme does result in higher average WDI input
current than does the method of leaving WDI low for the
majority of the timeout period and periodically pulsing it
low-high-low.
Layout Considerations
SRT and SWT are precision current sources. When
developing the layout for the application, be careful to
minimize board capacitance and leakage currents
around these pins. Traces connected to these pins
Figure 10. Ensuring RESET Valid to V CC = 0V
START
SET WDI
LOW
SUBROUTINE OR
PROGRAM LOOP
SET WDI HIGH
RETURN
END
Figure 11. Watchdog Flow Diagram
should be kept as short as possible. Traces carrying
high-speed digital signals and traces with large voltage
potentials should be routed as far from these pins as
possible. Leakage currents and stray capacitance
(e.g., a scope probe) at these pins could cause errors
in the reset and/or watchdog timeout period. When
evaluating these parts, use clean prototype boards to
ensure accurate reset and watchdog timeout periods.
RESET IN is a high-impedance input that is typically
driven by a high-impedance resistor-divider network
(e.g., 1M ? to 10M ? ). Minimize coupling to transient sig-
nals by keeping the connections to this input short. Any
DC leakage current at RESET IN (e.g., a scope probe)
causes errors in the programmed reset threshold. Note
that sensitive pins are located on the GND side of the
device, away from the digital I/O, to simplify board layout.
10
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MAX6302CPA+ 功能描述:监控电路 5V uPower 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
MAX6302CSA 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
MAX6302CSA+ 功能描述:监控电路 5V uPower 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
MAX6302CSA+T 功能描述:监控电路 5V uPower 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
MAX6302CSA-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