参数资料
型号: ST72F324K2B1
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32
封装: 0.400 INCH, SHRINK, PLASTIC, DIP-32
文件页数: 49/156页
文件大小: 1012K
代理商: ST72F324K2B1
ST72324J/K
142/156
ADC CHARACTERISTICS (Cont’d)
12.12.1 PCB Design Guidelines
The VAREF and VSSA pins supply power to the A/D
converter cell and function as the high and low ref-
erence voltages for the conversion. Separation of
the digital and analog power pins allow board de-
signers to improve A/D performance. Conversion
accuracy can be impacted by voltage drops and
noise in the event of heavily loaded or badly de-
coupled power supply lines.
To obtain best results, some general design and
layout rules should be followed when designing
the application PCB to shield the the noise-sensi-
tive, analog physical interface from noise-generat-
ing CMOS logic signals.
– Use separate digital and analog planes. The an-
alog ground plane should be connected to the
digital ground plane via a single point on the
PCB.
– Filter power to the analog power planes. The
best solution is to connect capacitors, with good
high frequency characteristics, between the
power and ground lines, placing 0.1
F and 10pF
capacitors as close as possible to the ST7 power
supply pins and a 10
F capacitor close to the
power source (see Figure 88).
– The analog and digital power supplies should be
connected in a star network. Do not use a resis-
tor, as VAREF is used as a reference voltage by
the A/D converter and any resistance would
cause a voltage drop and a loss of accuracy.
– Properly place components and route the signal
traces on the PCB to shield the analog inputs.
Analog signal paths should run over the analog
ground plane and be as short as possible. Isolate
analog signals from digital signals that may
switch while the analog inputs are being sampled
by the A/D converter. Do not toggle digital out-
puts on the same I/O port as the A/D input being
converted.
Figure 88. Power Supply Filtering
VSS
VDD
0.1
F
10pF
VDD
ST72XXX
VAREF
VSSA
POWER
SUPPLY
SOURCE
ST7
DIGITAL NOISE
FILTERING
EXTERNAL
NOISE
FILTERING
10
F
0.1
F
10pF
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相关代理商/技术参数
参数描述
ST72F324K2B6 功能描述:8位微控制器 -MCU 5V RANGE 8B MCU 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
ST72F324K2T3 制造商:STMicroelectronics 功能描述:
ST72F324K2T3TR 制造商:STMicroelectronics 功能描述:
ST72F324K2T6 功能描述:8位微控制器 -MCU Flash 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
ST72F324K2T6TR 功能描述:8位微控制器 -MCU 8 BITS MICROCONTR 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