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参数资料
型号： ST72T331J4T1
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, PQFP44
封装： PLASTIC, TQFP-44
文件页数： 18/107页
文件大小： 691K
代理商： ST72T331J4T1
18/107
ST72E331 ST72T331
3 CLOCKS, RESET, INTERRUPTS & POWER SAVING MODES
3.1 CLOCK SYSTEM
3.1.1 General Description
The MCU accepts either a crystal or ceramic reso-
nator, or an external clock signal to drive the inter-
nal oscillator. The internal clock (fCPU) is derived
from the external oscillator frequency (fOSC). The
external Oscillator clock is first divided by 2, and
an additional division factor of 2, 4, 8, or 16 can be
applied, in Slow Mode, to reduce the frequency of
the fCPU; this clock signal is also routed to the on-
chip peripherals. The CPU clock signal consists of
a square wave with a duty cycle of 50%.
The internal oscillator is designed to operate with
an AT-cut parallel resonant quartz crystal resona-
tor in the frequency range specified for fosc.The
circuit shown in Figure 11 is recommended when
using a crystal, and Table 5 lists the recommend-
ed capacitance and feedback resistance values.
The crystal and associated components should be
mounted as close as possible to the input pins in
order to minimize output distortion and start-up
stabilisation time.
Use of an external CMOS oscillator is recom-
mended when crystals outside the specified fre-
quency ranges are to be used.
3.1.2 External Clock
An external clock may be applied to the OSCIN in-
put with the OSCOUT pin not connected, as
shown on Figure 10.
Table 5 Recommended Values for 16 MHz
Crystal Resonator (C0 < 7pF)
RSMAX: Parasitic series resistance of the quartz
crystal (upper limit).
C0: Parasitic shunt capacitance of the quartz crys-
tal (upper limit 7pF).
COSCOUT,COSCIN: Maximum total capacitance on
pins OSCIN and OSCOUT (the value includes the
external capacitance tied to the pin plus the para-
sitic capacitance of the board and of the device).
Figure 10. External Clock Source Connections
Figure 11. Crystal/Ceramic Resonator
Figure 12. Clock Prescaler Block Diagram
RSMAX
40
60
150
COSCIN
56pF
47pF
22pF
COSCOUT
56pF
47pF
22pF
OSCIN
OSCOUT
EXTERNAL
CLOCK
NC
OSCIN
OSCOUT
COSCIN
COSCOUT
OSCIN
OSCOUT
COSCIN
COSCOUT
%2
% 2,4,8, 16
fCPU
to CPU and
Peripherals
18
相关PDF资料
PDF描述
ST72T331N2B1S 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDIP56
ST72T331N2T3 8-BIT, OTPROM, 4 MHz, MICROCONTROLLER, PQFP64
ST72T331N2B3S 8-BIT, OTPROM, 4 MHz, MICROCONTROLLER, PDIP56
ST72T331N4B3S 8-BIT, OTPROM, 4 MHz, MICROCONTROLLER, PDIP56
ST72T331J4B3 8-BIT, OTPROM, 4 MHz, MICROCONTROLLER, PDIP42
相关代理商/技术参数
参数描述
ST72T331J4T6 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
ST72T331J4T6S 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
ST72T331N2B6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI/SCI 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
ST72T331N2B6S 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI/SCI 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
ST72T331N2T6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI/SCI 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
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