参数资料
型号: MAX6750KA18-T
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: 电源管理
英文描述: µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
中文描述: 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO8
封装: SOT-23, 8 PIN
文件页数: 12/14页
文件大小: 170K
代理商: MAX6750KA18-T
Detailed Description
The MAX6746–MAX6753 assert a reset signal whenever
the VCC supply voltage or RESET IN falls below its reset
threshold. The reset output remains asserted for the
reset timeout period after VCC and RESET IN rise above
its respective reset threshold. A watchdog timer triggers
a reset pulse whenever a watchdog fault occurs.
The reset and watchdog delays are adjustable with
external capacitors. The MAX6746–MAX6751 contain a
watchdog select input that extends the watchdog time-
out period to 128x.
The MAX6752 and MAX6753 have a sophisticated
watchdog timer that detects when the processor is run-
ning outside an expected window of operation. The
watchdog signals a fault when the input pulses arrive too
early (faster that the selected tWD1 timeout period) or too
late (slower than the selected tWD2 timeout period) (see
Figure 1).
Reset Output
The reset output is typically connected to the reset input
of a P. A P’s reset input starts or restarts the P in a
known state. The MAX6746–MAX6753 P supervisory
circuits provide the reset logic to prevent code-execu-
tion errors during power-up, power-down, and
brownout conditions (see the
Typical Operating Circuit).
RESET changes from high to low whenever the moni-
tored voltage, RESET IN and/or VCC drop below the
reset threshold voltages. Once VRESET IN and/or VCC
exceeds its respective reset threshold voltage(s),
RESET remains low for the reset timeout period, then
goes high.
RESET is guaranteed to be in the correct logic state for
VCC greater than 1V. For applications requiring valid
reset logic when VCC is less than 1V, see the section
Ensuring a Valid RESET Output Down to VCC = 0V.
RESET IN Threshold
The MAX6748–MAX6751 monitor the voltage on RESET IN
using an adjustable reset threshold (VRESET IN) set with
an external resistor voltage-divider (Figure 2). Use the
following formula to calculate the externally monitored
voltage (VMON_TH):
VMON_TH = VRESET IN x (R1 + R2) / R2
MAX6746–MAX6753
P Reset Circuits with Capacitor-Adjustable
Reset/Watchdog Timeout Delay
_______________________________________________________________________________________
7
Figure 1. MAX6752/MAX6753 Detailed Watchdog Input Timing Relationship
MAX6748
MAX6749
MAX6750
MAX6751
RESET IN
GND
VCC
VMON_TH
VMON_TH = 1.235 x (R1 + R2) / R2
R1
R2
Figure 2. Calculating the Monitored Threshold Voltage
(VMON_TH)
WDI CONDITION 1
WDI CONDITION 2
WDI CONDITION 3
GUARANTEED TO
NOT ASSERT
RESET
GUARANTEED TO
ASSERT
RESET
tWD1 (MIN) tWD1 (MAX)
*UNDETERMINED
FAST FAULT
NORMAL OPERATION
SLOW FAULT
*UNDETERMINED STATES MAY OR MAY NOT GENERATE A FAULT CONDITION
GUARANTEED
TO ASSERT
RESET
tWD2 (MIN) tWD2 (MAX)
相关PDF资料
PDF描述
MAX6750KA19-T µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
MAX6750KA20-T µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
MAX6750KA21-T µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
MAX6750KA22-T µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
MAX6750KA24-T µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay
相关代理商/技术参数
参数描述
MAX6750KA19 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL-VOLT MICROPROC. RESET C - Rail/Tube
MAX6750KA19+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
MAX6750KA19-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
MAX6750KA20 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL-VOLT MICROPROC. RESET C - Rail/Tube
MAX6750KA20+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