参数资料
型号: AD9258BCPZ-125
厂商: Analog Devices Inc
文件页数: 36/44页
文件大小: 0K
描述: IC ADC 14BIT 125MSPS DL 64LFCSP
设计资源: High Performance, Dual Channel IF Sampling Receiver (CN0140)
标准包装: 1
位数: 14
采样率(每秒): 125M
数据接口: 串行
转换器数目: 2
功率耗散(最大): 788mW
电压电源: 模拟和数字
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 64-VFQFN 裸露焊盘,CSP
供应商设备封装: 64-LFCSP-VQ(9x9)
包装: 托盘
输入数目和类型: 2 个差分,单极
AD9258
Rev. A | Page 41 of 44
APPLICATIONS INFORMATION
DESIGN GUIDELINES
Before starting design and layout of the AD9258 as a system,
it is recommended that the designer become familiar with these
guidelines, which discuss the special circuit connections and
layout requirements that are needed for certain pins.
Power and Ground Recommendations
When connecting power to the AD9258, it is recommended that
two separate 1.8 V supplies be used. Use one supply for analog
(AVDD); use a separate supply for the digital outputs (DRVDD).
For both AVDD and DRVDD several different decoupling capa-
citors should be used to cover both high and low frequencies.
Place these capacitors close to the point of entry at the PCB level
and close to the pins of the part, with minimal trace length.
A single PCB ground plane should be sufficient when using the
AD9258. With proper decoupling and smart partitioning of the
PCB analog, digital, and clock sections, optimum performance
is easily achieved.
LVDS Operation
The AD9258 defaults to CMOS output mode on power-up.
If LVDS operation is desired, this mode must be programmed,
using the SPI configuration registers after power-up. When the
AD9258 powers up in CMOS mode with LVDS termination
resistors (100 Ω) on the outputs, the DRVDD current can be
higher than the typical value until the part is placed in LVDS
mode. This additional DRVDD current does not cause damage
to the AD9258, but it should be taken into account when consid-
ering the maximum DRVDD current for the part.
To avoid this additional DRVDD current, the AD9258 outputs
can be disabled at power-up by taking the OEB pin high. After
the part is placed into LVDS mode via the SPI port, the OEB
pin can be taken low to enable the outputs.
Exposed Paddle Thermal Heat Slug Recommendations
It is mandatory that the exposed paddle on the underside of the
ADC be connected to analog ground (AGND) to achieve the
best electrical and thermal performance. A continuous, exposed
(no solder mask) copper plane on the PCB should mate to the
AD9258 exposed paddle, Pin 0.
The copper plane should have several vias to achieve the lowest
possible resistive thermal path for heat dissipation to flow through
the bottom of the PCB. These vias should be filled or plugged to
prevent solder wicking through the vias, which can compromise
the connection.
To maximize the coverage and adhesion between the ADC and
the PCB, a silkscreen should be overlaid to partition the continuous
plane on the PCB into several uniform sections. This provides
several tie points between the ADC and the PCB during the reflow
process. Using one continuous plane with no partitions guarantees
only one tie point between the ADC and the PCB. For detailed
information about packaging and PCB layout of chip scale
packages, see the AN-772 Application Note, A Design and
Manufacturing Guide for the Lead Frame Chip Scale Package
(LFCSP), at www.analog.com.
VCM
The VCM pin should be decoupled to ground with a 0.1 μF
capacitor, as shown in Figure 67.
RBIAS
The AD9258 requires that a 10 kΩ resistor be placed between
the RBIAS pin and ground. This resistor sets the master current
reference of the ADC core and should have at least a 1% tolerance.
Reference Decoupling
The VREF pin should be externally decoupled to ground with
a low ESR, 1.0 μF capacitor in parallel with a low ESR, 0.1 μF
ceramic capacitor.
SPI Port
The SPI port should not be active during periods when the full
dynamic performance of the converter is required. Because the
SCLK, CSB, and SDIO signals are typically asynchronous to the
ADC clock, noise from these signals can degrade converter
performance. If the on-board SPI bus is used for other devices,
it may be necessary to provide buffers between this bus and the
AD9258 to keep these signals from transitioning at the converter
inputs during critical sampling periods.
相关PDF资料
PDF描述
AD9259ABCPZRL7-50 IC ADC 14BIT SRL 50MSPS 48LFCSP
AD9260ASZRL IC ADC 16BIT 2.5MHZ 44MQFP
AD9262BCPZ-10 IC ADC 16BIT 10MHZ 64LFCSP
AD9266BCPZRL7-20 IC ADC 16BIT 20MSPS 32LFCSP
AD9269BCPZRL7-20 IC ADC 16BIT 20MSPS DL 64LFCSP
相关代理商/技术参数
参数描述
AD9258BCPZ-1251 制造商:AD 制造商全称:Analog Devices 功能描述:14-Bit, 80 MSPS/105 MSPS/125 MSPS, 1.8 V Dual Analog-to-Digital Converter (ADC)
AD9258BCPZ-80 功能描述:模数转换器 - ADC Dual 14 bit 80 high SNR ADC RoHS:否 制造商:Analog Devices 通道数量: 结构: 转换速率: 分辨率: 输入类型: 信噪比: 接口类型: 工作电源电压: 最大工作温度: 安装风格: 封装 / 箱体:
AD9258BCPZ-801 制造商:AD 制造商全称:Analog Devices 功能描述:14-Bit, 80 MSPS/105 MSPS/125 MSPS, 1.8 V Dual Analog-to-Digital Converter (ADC)
AD9258BCPZRL7-105 功能描述:模数转换器 - ADC Dual 14 bit 105 highSNR ADC RoHS:否 制造商:Analog Devices 通道数量: 结构: 转换速率: 分辨率: 输入类型: 信噪比: 接口类型: 工作电源电压: 最大工作温度: 安装风格: 封装 / 箱体:
AD9258BCPZRL7-1051 制造商:AD 制造商全称:Analog Devices 功能描述:14-Bit, 80 MSPS/105 MSPS/125 MSPS, 1.8 V Dual Analog-to-Digital Converter (ADC)