参数资料
型号: MAX791EPE+
厂商: Maxim Integrated Products
文件页数: 13/19页
文件大小: 0K
描述: IC SUPERVISOR MPU 16-DIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 25
类型: 备用电池电路
监视电压数目: 1
输出: 推挽式,图腾柱
复位: 低有效
复位超时: 最小为 140 ms
电压 - 阀值: 4.65V
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
Microprocessor Supervisory Circuit
RESET
THRESHOLD
VBATT
1
V CC
200ms TYP
2
0.1 μ F
V OUT
RESET
V CC
3
MAX791
CE IN
CE OUT
SECOND CE PULSE ABSENT WHEN VBATT < 2V
Figure 10. V CC and VBATT-to-V OUT Switch
Battery On Output
The Battery On (BATT ON) output indicates the status
of the internal V CC /battery-switchover comparator,
which controls the internal V CC and VBATT switches.
For V CC greater than VBATT (ignoring the small hys-
teresis effect), BATT ON typically sinks 3.2mA at 0.1V
saturation voltage. In battery-backup mode, this termi-
nal sources approximately 10μA from V OUT . Use BATT
ON to indicate battery-switchover status or to supply
base drive to an external pass transistor for higher-cur-
rent applications (see Typical Operating Circuit ).
Input Supply Voltage
The Input Supply Voltage (V CC ) should be a regulated
+5V. V CC connects to V OUT via a parallel diode and a
large PMOS switch. The switch carries the entire cur-
rent load for currents less than 250mA. The parallel
diode carries any current in excess of 250mA. Both the
switch and the diode have impedances less than 1 ?
each (Figure 10). The maximum continuous current is
250mA, but power-on transients may reach a maximum
of 1A.
Backup-Battery Input
The Backup-Battery Input (VBATT) is similar to V CC ,
except the PMOS switch and parallel diode are much
smaller. Accordingly, the on-resistances of the diode
and the switch are each approximately 10 ? .
Continuous current should be limited to 25mA and peak
currents (only during power-up) limited to 250mA. The
Figure 11. Backup-Battery Monitor Timing Diagram
reverse leakage of this input is less than 1μA over tem-
perature and supply voltage.
Output Supply Voltage
The Output Supply Voltage (V OUT ) is internally connect-
ed to the substrate of the IC and supplies all the current
to the external system and internal circuitry. All open-
circuit outputs will, for example, assume the V OUT volt-
age in their high states rather than the V CC voltage. At
the maximum source current of 250mA, V OUT will typi-
cally be 200mV below V CC . Decouple this terminal with
a 0.1μF capacitor.
Low-Battery Monitor
The MAX791 low-battery voltage function monitors
VBATT. Low-battery detection of 2.0V ±0.15V is moni-
tored only during the reset-timeout period (200ms) that
occurs either after a normal power-up sequence or
after the MR reset input has been returned to its high
state. If the battery voltage is below 2.0V, the second
CE pulse is inhibited after reset timeout. If the battery
voltage is above 2.0V, all CE pulses are allowed
through the CE gate after the reset timeout period. To
use this function, after the 200ms reset delay, write 00
(HEX) to a location using the first CE pulse, and write
FF (HEX) to the same location using the second CE
pulse following RESET going inactive on power-up. The
contents of the memory then indicates a good battery
(FF) or a low battery (00) (Figure 11).
______________________________________________________________________________________
13
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MAX791EPE+ 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
MAX791ESE 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
MAX791ESE+ 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
MAX791ESE+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
MAX791ESE-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