参数资料
型号: ST72T121J4B6S
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDIP42
封装: 0.600 INCH, PLASTIC, SDIP-42
文件页数: 9/93页
文件大小: 1374K
代理商: ST72T121J4B6S
17/93
ST72E121 ST72T121
RESET (Cont’d)
3.2.4 Low Voltage Detector Reset
The on-chip Low Voltage Detector (LVD) gener-
ates a static reset when the supply voltage is be-
low a reference value. The LVD functions both
during power-on as well as when the power supply
drops (brown-out). The reference value for a volt-
age drop is lower than the reference value for pow-
er-on in order to avoid a parasitic reset when the
MCU starts running and sinks current on the sup-
ply (hysteresis).
The LVD Reset circuitry generates a reset when
VDD is below:
VLVDUP when VDD is rising
VLVDDOWN when VDD is falling
Provided the minimun VDD value (guaranteed for
the oscillator frequency) is above VLVDDOWN , the
MCU can only be in two modes:
- under full software control or
- in static safe reset
In this condition, secure operation is always en-
sured for the application without the need for ex-
ternal reset hardware.
During a Low Voltage Detector Reset, the RESET
pin is held low, thus permitting the MCU to reset
other devices.
In noisy environments, the power supply may drop
for short periods and cause the Low Voltage De-
tector to generate a Reset too frequently. In such
cases, it is recommended to use devices without
the LVD Reset option and to rely on the watchdog
function to detect application runaway conditions.
Figure 12. Low Voltage Detector Reset Function
Figure 13. Low Voltage Detector Reset Signal
Note: See electrical characteristics for values of
VLVDUP and VLVDDOWN
Figure 14. Temporization timing diagram after an internal Reset
LOW VOLTAGE
DETECTOR RESET
VDD
FROM
WATCHDOG
RESET
VDD
VLVDUP
VLVDDOWN
VDD
Addresses
$FFFE
Temporization (4096 CPU clock cycles)
VLVDUP
17
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相关代理商/技术参数
参数描述
ST72T121J4T6 功能描述:8位微控制器 -MCU OTP EPROM 16K SPI/SC RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T121J4T6S 制造商:STMicroelectronics 功能描述:
ST72T141K2B6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T141K2M6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T212G2B6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT