参数资料
型号: DS1236A-5+
厂商: Maxim Integrated Products
文件页数: 3/20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: 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
DS1236A
POWER MONITOR
The DS1236A employs a band gap voltage reference and a precision comparator to monitor the 5-volt
supply (V CC ) in microprocessor-based systems. When an out-of-tolerance condition occurs, the RST and
RST outputs are driven to the active state. The V CC trip point (V CCTP ) is set for 10% operation so that the
RST and RST outputs will become active as V CC falls below 4.5 volts (4.37 typical). The V CCTP for the
5% operation option (DS1236A-5) is set for 4.75 volts (4.62 typical). The RST and RST signals are
excellent for microprocessor reset control, as processing is stopped at the last possible moment of in-
tolerance V CC . On power-up, the RST and RST signals are held active for a minimum of 25 ms (100 ms
typical) after V CCTP is reached to allow the power supply and microprocessor to stabilize. Note: The
operation described above is obtained with the reset control pin (RC) connected to GND (NMOS mode).
Please review the reset control section for more information.
WATCHDOG TIMER
The DS1236A provides a watchdog timer function which forces the RST and RST signals to the active
state when the strobe input ( ST ) is not stimulated for a predetermined time period. This time period is 400
ms typically with a maximum timeout of 600 ms. The watchdog timeout period begins as soon as RST
and RST are inactive. If a high-to-low transition occurs at the ST input prior to timeout, the watchdog
timer is reset and begins to time out again. The ST input timing is shown in NO TAG. To guarantee the
watchdog timer does not time out, a high-to-low transition on ST must occur at or less t han 100 ms
(minimum timeout) from a reset. If the watchdog timer is allowed to time out, the RST and RST outputs
are driven to the active state for 25 ms minimum. The ST input can be derived from microprocessor
address, data, and/or control signals. Under normal operating conditions, these signals would routinely
reset the watchdog timer prior to timeout. If the watchdog timer is not required, two methods have been
provided to disable it.
Permanently grounding the IN pin in the CMOS mode (RC=1) will disable the watchdog. In normal
operation with RC=1, the watchdog is disabled as soon as the IN pin is below V TP . With IN grounded, an
NMI output will occur only at power-up, or when the ST pin is strobed. As shown in the NO TAG, a
falling edge on ST will generate an NMI when IN is below V TP . This allows the processor to verify that
power is between V TP and V CCTP , as an NMI will be returned immediately after the ST strobe. The
watchdog timer is not affected by the IN pin when in NMOS mode (RC=0).
If the NMI signal is required to monitor supply voltages, the watchdog may also be disabled by leaving
the ST input open. Independent of the state of the RC pin, the watchdog is also disabled as soon as V CC
falls to V CCTP .
PUSHBUTTON RESET
An input pin is provided on the DS1236A for direct connection to a pushbutton. The pushbutton reset
input requires an active low signal. Internally, this input is pulled high by a 10k resistor whenever V CC is
greater than V BAT . The PBRST pin is also debounced and timed such that the RST and RST outputs are
driven to the active state for 25 ms minimum. This 25 ms delay begins as the pushbutton is released from
a low level. A typical example of the power monitor, watchdog timer, and pushbutton reset connections
are shown in NO TAG. The PBRST input is disabled whenever the IN pin voltage level is less than V TP
and the reset control (RC) is tied high (CMOS mode). The PBRST input is also disabled whenever V CC is
below V BAT . Timing of the PBRST -generated RST is illustrated in Figure 1.
3 of 20
相关PDF资料
PDF描述
RCM28DTAD-S189 CONN EDGECARD 56POS R/A .156 SLD
DS1238AS-5+ IC MICRO MANAGER 5% 16-SOIC
ECM36DTBN-S273 CONN EDGECARD 72POS R/A .156 SLD
EBM36DTBT-S189 CONN EDGECARD 72POS R/A .156 SLD
ECM36DTBD-S273 CONN EDGECARD 72POS R/A .156 SLD
相关代理商/技术参数
参数描述
DS1236A-5+ 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
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
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