参数资料
型号: DS1236A-5N+
厂商: Maxim Integrated Products
文件页数: 4/20页
文件大小: 0K
描述: IC MICROMANAGER 5% 16-DIP
标准包装: 25
系列: MicroManager
类型: 备用电池电路
监视电压数目: 1
输出: 开路漏极,推挽式
复位: 高有效/低有效
复位超时: 最小为 25 ms
电压 - 阀值: 4.62V
工作温度: -40°C ~ 85°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
DS1236A
NON-MASKABLE INTERRUPT
The DS1236A generates a non-maskable interrupt NMI for early warning of power failure to a
microprocessor. A precision comparator monitors the voltage level at the IN pin relative to a reference
generated by the internal band gap. The IN pin is a high-impedance input allowing for a user-defined
sense point. An external resistor voltage divider network (NO TAG) is used to interface with high voltage
signals. This sense point may be derived from the regulated 5-volt supply or from a higher DC voltage
level closer to the main system power input. Since the IN trip point V TP is 2.54 volts, the proper values
for R1 and R2 can be determined by the equation as shown in NO TAG. Proper operation of the
DS1236A requires that the voltage at the IN pin be limited to V IN . Therefore, the maximum allowable
voltage at the supply being monitored (V MAX ) can also be derived as shown in NO TAG. A simple
approach to solving this equation is to select a value for R2 high enough to keep power consumption low,
and solve for R1. The flexibility of the IN input pin allows for detection of power loss at the earliest p oin t
in a power supply system, maximizing the amount of time for microprocessor shutdown between NMI
and RST or RST .
When the supply being monitored decays to the voltage sense point, the DS1236A pulses the NMI output
to the active state for a minimum of 200 μ s. The NMI power-fail detection circuitry also has built-in time
domain hysteresis. That is, the monitored supply is sampled periodically at a rate determined by an
internal ring oscillator running at approximately 30 kHz (33 μ s/cycle). Three consecutive samplings of
out-of-tolerance supply (below V SENSE ) must occur at the IN pin to activate NMI . Therefore, the supply
must be below the voltage sense point for approximately 100 μ s or the comparator will reset. In this way,
power supply noise is removed from the monitoring function, preventing false trips. During a power-up,
any detected IN pin levels be low V TP by the comparator are disabled from reaching the NMI pin until
V CC rises to V CCTP . As a result, any potential NMI pulse will not be initiated until V CC reaches V CCTP .
Removal of an active low level on the NMI pin is controlled by either an internal timeout (when IN pin is
less than V TP ) or by the subsequent rise of the IN pin above V TP . The initiation and removal of the NMI
signal during power-up results in an NMI pulse of from 0 μ s minimum to 500 μ s maximum, depending
on the relative voltage relationship between V CC and the IN pin voltage. As an example, when the IN pin
is tied to ground during power-up, the internal timeout will result in a pulse of 200 μ s minimum to 500 μ s
maximum. In contrast, if the IN pin is tied to V CCO during power-up, NMI will not produce a pulse on
power-up. Note that a fast-slewing power supply may cause the NMI to be virtually nonexistent on
power-up. This is of no consequence, however, since an RST will be active.
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相关代理商/技术参数
参数描述
DS1236A-5N+ 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
DS1236AN 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
DS1236AN-5 制造商:未知厂家 制造商全称:未知厂家 功能描述:Power Supply Supervisor
DS1236AS 制造商:未知厂家 制造商全称:未知厂家 功能描述:Power Supply Supervisor
DS1236AS-10 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