参数资料
型号: DS1236AS-5/T&R
厂商: Maxim Integrated Products
文件页数: 9/19页
文件大小: 0K
描述: IC MICROMANAGER 5% 16-SOIC
标准包装: 1,000
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: 表面贴装
封装/外壳: 16-SOIC(0.295",7.50mm 宽)
供应商设备封装: 16-SOIC W
包装: 带卷 (TR)
DS1236
When the RC pin is tied to ground, the DS1236 is designed to interface with NMOS processors which do
not have the microamp currents required during a battery backed mode. Grounding the RC pin does,
however, continue to support nonvolatile backup of system SRAM memory. Nonvolatile systems
incorporating NMOS processors generally require that only the SRAM memory and/or timekeeping
functions be battery backed. When the processor is not battery backed (RC = 0), all signals connected
from the processor to the DS1236 are disconnected from the backup battery supply, or grounded when
system V CC decays below V BAT . In the NMOS processor system, the principal emphasis is placed on
giving early warnings with NMI , then providing a continuously active RST and RST signal during
power-down while isolating the backup battery from the processor during a loss of V CC .
During power-down, NMI will pulse low for a minimum of 200 μ s, and then return high. If RC is tied
low (NMOS mode), the voltage on NMI will follow V CC until V CC supply decays to V BAT , at which point
NM I will enter tri-state (see timing diagram). Also, upon V CC out-of-tolerance at V CCTP , the RST and
RST outputs are driven active and RST will follow V CC as the supply decays. On power-up, RST follows
V CC up, RST is held low, and both remain active for t RST after valid V CC . During a power-up from a V CC
voltage below V BAT , any detected IN pin levels below V TP 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 time-out (when the 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 results in an NMI pulse of 0 μ s minimum to 500 μ s maximum during power-up, depending
on the relative voltage relationship between V CC and the IN pin. As an example, when the IN pin is tied to
ground, 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 , NMI will not produce a pulse on power-up.
Connecting the RC pin to a high (V CCO ) invokes CMOS mode and provides nonvolatile support to both
the system SRAM as well as a low power CMOS processor. When using CMOS microprocessors, it is
possible to place the microprocessor into a very low-power mode termed the “stop” or “halt” mode. In
this state the CMOS processor requires only microamp currents and is fully capable of being battery
backed. This mode generally allows the CMOS microprocessor to maintain the contents of internal RAM
as well as state control of I/O ports during battery backup. The processor can subsequently be restarted by
any of several different signals. To maintain this low-power state, the DS1236 issues no NMI and/or reset
signals to the processor until it is time to bring the processor back into full operation. To support the low-
power processor battery backed mode (RC = 1), the DS1236 provides a pulsed NMI for early power
failure warning. Waiting to initiate a Stop mode until after the NMI pin has returned high will guarantee
the processor that no other active NMI or RST/ RST will be issued by the DS1236 until one of two
conditions occurs: 1) Voltage on the pin rises above V TP , which activates the watchdog, or 2) V CC cycles
below then above V BAT , which also results in an active RST and RST . If V CC does not fall below V CCTP ,
the processor will be restarted by the reset derived from the watchdog timer as the IN pin rises above V TP .
With the RC pin tied to V CCO , RST and RST are not forced active as V CC collapses to V CCTP . The RST is
held at a high level via the external battery as V CC falls below battery potential. This mode of operation is
intended for applications in which the processor is made nonvolatile with an external source, and allows
the processor to power down into a Stop mode as signaled from NMI at an earlier voltage level. The NMI
output pin will pulse low for t NMI following a low voltage detect at the IN pin of V TP . Following t NMI ,
however, NMI will also be held at a high level (V BAT ) by the battery as V CC decays below V BAT . On
power-up, RST and RST are held inactive until V CC reaches V BAT , then RST and RST are driven active
for t RST . If the IN pin falls below V TP during an active reset, the reset outputs will be forced inactive by
the NMI output. In addition, as long as the IN pin is less than V TP , stimulation of the ST pin will result in
9 of 19
相关PDF资料
PDF描述
TC2185-3.3VCTTR IC REG LDO 3.3V .15A SOT23A-5
TC2185-3.0VCTTR IC REG LDO 3V .15A SOT23A-5
RBM43DTMN CONN EDGECARD 86POS R/A .156 SLD
RBM43DTMD CONN EDGECARD 86POS R/A .156 SLD
RBM43DTMH CONN EDGECARD 86POS R/A .156 SLD
相关代理商/技术参数
参数描述
DS1236ASN 制造商:未知厂家 制造商全称:未知厂家 功能描述:Power Supply Supervisor
DS1236ASN-5 制造商:未知厂家 制造商全称:未知厂家 功能描述:Power Supply Supervisor
DS1236N 制造商:未知厂家 制造商全称:未知厂家 功能描述:Power Supply Supervisor
DS1236N-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
DS1236N-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