参数资料
型号: ADUC7126BSTZ126-RL
厂商: Analog Devices Inc
文件页数: 5/108页
文件大小: 0K
描述: IC MCU 16/32B 126KB FLASH 80LQFP
标准包装: 1,000
系列: MicroConverter® ADuC7xxx
核心处理器: ARM7
芯体尺寸: 16/32-位
速度: 41.78MHz
连通性: EBI/EMI,I²C,SPI,UART/USART
外围设备: POR,PWM,WDT
输入/输出数: 40
程序存储器容量: 126KB(63K x 16)
程序存储器类型: 闪存
RAM 容量: 32K x 8
电压 - 电源 (Vcc/Vdd): 2.7 V ~ 3.6 V
数据转换器: A/D 12x12b,D/A 4x12b
振荡器型: 内部
工作温度: -40°C ~ 125°C
封装/外壳: 80-LQFP
包装: 带卷 (TR)
ADuC7124/ADuC7126
Data Sheet
Rev. C | Page 102 of 108
GROUNDING AND BOARD LAYOUT
RECOMMENDATIONS
As with all high resolution data converters, special attention
must be paid to grounding and PC board layout of the
ADuC7124/ADuC7126-based designs to achieve optimum
performance from the ADCs and DAC.
Although the part has separate pins for analog and digital ground
(AGND and IOGND), the user must not tie these to two sepa-
rate ground planes unless the two ground planes are connected
very close to the part. This is illustrated in the simplified example
shown in Figure 66a. In systems where digital and analog
ground planes are connected together somewhere else (at the
power supply of the system, for example), the planes cannot be
reconnected near the part because a ground loop results. In these
cases, tie all the ADuC7124/ADuC7126 AGND and IOGND
pins to the analog ground plane, as illustrated in Figure 66b.
In systems with only one ground plane, ensure that the digital
and analog components are physically separated onto separate
halves of the board so that digital return currents do not flow
near analog circuitry (and vice versa).
The ADuC7124/ADuC7126 can then be placed between the
digital and analog sections, as illustrated in Figure 66c.
09
12
3-
0
47
a.
PLACE ANALOG
COMPONENTS HERE
PLACE DIGITAL
COMPONENTS HERE
AGND
DGND
b.
PLACE ANALOG
COMPONENTS
HERE
PLACE DIGITAL
COMPONENTS HERE
AGND
DGND
c.
PLACE ANALOG
COMPONENTS HERE
PLACE DIGITAL
COMPONENTS HERE
DGND
Figure 66. System Grounding Schemes
In all of these scenarios, and in more complicated real-life
applications, the users should pay particular attention to the
flow of current from the supplies and back to ground. Make
sure the return paths for all currents are as close as possible to
the paths the currents took to reach their destinations.
For example, do not power components on the analog side (as
seen in Figure 66b) with IOVDD because that forces return
currents from IOVDD to flow through AGND. Avoid digital
currents flowing under analog circuitry, which can occur if a
noisy digital chip is placed on the left half of the board (shown
in Figure 66c). If possible, avoid large discontinuities in the
ground plane(s), such as those formed by a long trace on the same
layer, because they force return signals to travel a longer path.
In addition, make all connections to the ground plane directly,
with little or no trace separating the pin from its via to ground.
When connecting fast logic signals (rise/fall time < 5 ns) to any of
the ADuC7124/ADuC7126 digital inputs, add a series resistor to
each relevant line to keep rise and fall times longer than 5 ns at
the input pins of the part. A value of 100 Ω or 200 Ω is usually
sufficient to prevent high speed signals from coupling capaci-
tively into the part and affecting the accuracy of ADC conversions.
CLOCK OSCILLATOR
The clock source for the ADuC7124/ADuC7126 can be generated
by the internal PLL or by an external clock input. To use the
internal PLL, connect a 32.768 kHz parallel resonant crystal
between XCLKI and XCLKO, and connect a capacitor from
each pin to ground as shown in Figure 67. The crystal allows the
PLL to lock correctly to give a frequency of 41.78 MHz. If no
external crystal is present, the internal oscillator is used to give
a typical frequency of 32.768 kHz ± 3%.
09123
-048
ADuC7124/
ADuC7126
TO
INTERNAL
PLL
12pF
XCLKI
32.768kHz
12pF
XCLKO
Figure 67. External Parallel Resonant Crystal Connections
To use an external source clock input instead of the PLL (see
Figure 68), Bit 1 and Bit 0 of PLLCON must be modified. The
external clock uses P0.7 and XCLK.
09123
-049
ADuC7124/
ADuC7126
TO
FREQUENCY
DIVIDER
XCLKO
XCLKI
XCLK
EXTERNAL
CLOCK
SOURCE
Figure 68. Connecting an External Clock Source
Using an external clock source, the ADuC7124/ADuC7126
specified operational clock speed range is 50 kHz to 41.78 MHz
± 1%, which ensures correct operation of the analog peripherals
and Flash/EE.
相关PDF资料
PDF描述
ADUC7129BSTZ126 IC DAS MCU ARM7 ADC/DDS 80-LQFP
ADUC812BSZ-REEL IC MCU FLASH 12BIT ADC 52MQFP
ADUC814BRU IC ADC 12BIT W/FLASH MCU 28TSSOP
ADUC816BCP IC MCU 8K FLASH ADC/DAC 56LFCSP
ADUC824BSZ-REEL IC MCU 8K FLASH ADC/DAC 52MQFP
相关代理商/技术参数
参数描述
ADUC7128 制造商:AD 制造商全称:Analog Devices 功能描述:Precision Analog Microcontroller ARM7TDMI MCU with 12-bit ADC & DDS DAC
ADUC7128BCPZ126 功能描述:IC DAS MCU ARM7 ADC/DDS 64-LFCSP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:MicroConverter® ADuC7xxx 标准包装:250 系列:LPC11Uxx 核心处理器:ARM? Cortex?-M0 芯体尺寸:32-位 速度:50MHz 连通性:I²C,Microwire,SPI,SSI,SSP,UART/USART,USB 外围设备:欠压检测/复位,POR,WDT 输入/输出数:40 程序存储器容量:96KB(96K x 8) 程序存储器类型:闪存 EEPROM 大小:4K x 8 RAM 容量:10K x 8 电压 - 电源 (Vcc/Vdd):1.8 V ~ 3.6 V 数据转换器:A/D 8x10b 振荡器型:内部 工作温度:-40°C ~ 85°C 封装/外壳:48-LQFP 包装:托盘 其它名称:568-9587
ADUC7128BCPZ1262 制造商:AD 制造商全称:Analog Devices 功能描述:Precision Analog Microcontroller ARM7TDMI MCU with 12-Bit ADC and DDS DAC
ADUC7128BCPZ126-RL 功能描述:IC DAS MCU ARM7 ADC/DDS 64-LFCSP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:MicroConverter® ADuC7xxx 标准包装:38 系列:Encore!® XP® 核心处理器:eZ8 芯体尺寸:8-位 速度:5MHz 连通性:IrDA,UART/USART 外围设备:欠压检测/复位,LED,POR,PWM,WDT 输入/输出数:16 程序存储器容量:4KB(4K x 8) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:1K x 8 电压 - 电源 (Vcc/Vdd):2.7 V ~ 3.6 V 数据转换器:- 振荡器型:内部 工作温度:-40°C ~ 105°C 封装/外壳:20-SOIC(0.295",7.50mm 宽) 包装:管件 其它名称:269-4116Z8F0413SH005EG-ND
ADUC7128BCPZ126-RL2 制造商:AD 制造商全称:Analog Devices 功能描述:Precision Analog Microcontroller ARM7TDMI MCU with 12-Bit ADC and DDS DAC