参数资料
型号: AD9640ABCPZ-105
厂商: Analog Devices Inc
文件页数: 26/52页
文件大小: 0K
描述: IC ADC 14BIT 105MSPS 64LFCSP
设计资源: Interfacing ADL5534 to AD9640 High Speed ADC (CN0049)
标准包装: 1
位数: 14
采样率(每秒): 105M
数据接口: 串行,SPI?
转换器数目: 2
功率耗散(最大): 657mW
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: 4 个单端,单极;2 个差分,单极
AD9640
Rev. B | Page 32 of 52
ADC OVERRANGE AND GAIN CONTROL
In receiver applications, it is desirable to have a mechanism to
reliably determine when the converter is about to be clipped.
The standard overflow indicator provides after-the-fact infor-
mation on the state of the analog input that is of limited usefulness.
Therefore, it is helpful to have a programmable threshold below
full scale that allows time to reduce the gain before the clip
actually occurs. In addition, because input signals can have
significant slew rates, latency of this function is of major concern.
Highly pipelined converters can have significant latency. A good
compromise is to use the output bits from the first stage of the
ADC for this function. Latency for these output bits is very low,
and overall resolution is not highly significant. Peak input signals
are typically between full scale and 6 dB to 10 dB below full
scale. A 3-bit or 4-bit output provides adequate range and
resolution for this function.
Using the SPI port, the user can provide a threshold above which
an overrange output is active. As long as the signal is below that
threshold, the output should remain low. The fast detect outputs
can also be programmed via the SPI port so that one of the pins
functions as a traditional overrange pin for customers who
currently use this feature. In this mode, all 14 bits of the converter
are examined in the traditional manner, and the output is high for
the condition normally defined as overflow. In either mode, the
magnitude of the data is considered in the calculation of the
condition (but the sign of the data is not considered). The threshold
detection responds identically to positive and negative signals
outside the desired range (magnitude).
FAST DETECT OVERVIEW
The AD9640 contains circuitry to facilitate fast overrange detec-
tion, allowing very flexible external gain control implementations.
Each ADC has four fast detect (FD) output pins that are used
to output information about the current state of the ADC input
level. The function of these pins is programmable via the fast detect
mode select bits and the fast detect enable bit in Register 0x104,
allowing range information to be output from several points in
the internal datapath. These output pins can also be set up to
indicate the presence of overrange or underrange conditions,
according to programmable threshold levels. Table 17 shows the
six configurations available for the fast detect pins.
Table 17. Fast Detect Mode Select Bits Settings
Fast Detect
Mode Select Bits
(Register 0x104[3:1])
Information Presented on
Fast Detect (FD) Pins of Each ADC1, 2
FD3
FD2
FD1
FD0
000
ADC fast magnitude
(see Table 18)
001
ADC fast magnitude
(see Table 19)
OR
010
ADC fast magnitude
(see Table 20)
OR
F_LT
011
ADC fast magnitude
(see Table 20)
C_UT
F_LT
100
OR
C_UT
F_UT
F_LT
101
OR
F_UT
IG
DG
1 The fast detect pins are FD0A/FD0B to FD3A/FD3B for the CMOS mode
configuration and FD0+/FD0 to FD3+/FD3 for the LVDS mode configuration.
2 See the ADC Overrange (OR) and Gain Switching sections for more
information about OR, C_UT, F_UT, F_LT, IG, and DG.
ADC FAST MAGNITUDE
When the fast detect output pins are configured to output the ADC
fast magnitude (that is, when the fast detect mode select bits are
set to 0b000), the information presented is the ADC level from
an early converter stage with a latency of only two clock cycles
(when in CMOS output mode). Using the fast detect output pins
in this configuration provides the earliest possible level indication
information. Because this information is provided early in the
datapath, there is significant uncertainty in the level indicated.
The nominal levels, along with the uncertainty indicated by the
ADC fast magnitude, are shown in Table 18.
Table 18. ADC Fast Magnitude Nominal Levels with Fast Detect
Mode Select Bits = 000
ADC Fast
Magnitude on
FD[3:0] Pins
Nominal Input
Magnitude
Below FS (dB)
Nominal Input
Magnitude
Uncertainty (dB)
0000
<24
Minimum to 18.07
0001
24 to 14.5
30.14 to 12.04
0010
14.5 to 10
18.07 to 8.52
0011
10 to 7
12.04 to 6.02
0100
7 to 5
8.52 to 4.08
0101
5 to 3.25
6.02 to 2.5
0110
3.25 to 1.8
4.08 to 1.16
0111
1.8 to 0.56
2.5 to FS
1000
0.56 to 0
1.16 to 0
相关PDF资料
PDF描述
MS27467E19B11SA CONN PLUG 11POS STRAIGHT W/SCKT
IDT72805LB10PF8 IC FIFO SYNC DUAL 256X18 128TQFP
VI-J4B-MX-S CONVERTER MOD DC/DC 95V 75W
VI-25D-MX-F2 CONVERTER MOD DC/DC 85V 75W
LTC1350IG#TRPBF IC TXRX 3.3V EIA/TIA-562 28-SSOP
相关代理商/技术参数
参数描述
AD9640ABCPZ-125 功能描述:IC ADC 14BIT 125MSPS 64LFCSP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:250 系列:- 位数:12 采样率(每秒):1.8M 数据接口:并联 转换器数目:1 功率耗散(最大):1.82W 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:48-LQFP 供应商设备封装:48-LQFP(7x7) 包装:管件 输入数目和类型:2 个单端,单极
AD9640ABCPZ-150 功能描述:模数转换器 - ADC 14Bit 150Msps Dual 1.8V PB Free 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:
AD9640ABCPZ-80 功能描述:IC ADC 14BIT 80MSPS 64LFCSP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1 系列:- 位数:14 采样率(每秒):83k 数据接口:串行,并联 转换器数目:1 功率耗散(最大):95mW 电压电源:双 ± 工作温度:0°C ~ 70°C 安装类型:通孔 封装/外壳:28-DIP(0.600",15.24mm) 供应商设备封装:28-PDIP 包装:管件 输入数目和类型:1 个单端,双极
AD9640ABCPZRL7-105 功能描述:模数转换器 - ADC 14Bit 105Msps Dual 1.8V PB Free 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:
AD9640ABCPZRL7-125 功能描述:14 Bit Analog to Digital Converter 2 Input 2 Pipelined 64-LFCSP-VQ (9x9) 制造商:analog devices inc. 系列:- 包装:带卷(TR) 零件状态:在售 位数:14 采样率(每秒):125M 输入数:2 输入类型:差分,单端 数据接口:并联 配置:S/H-ADC 无线电 - S/H:ADC:1:1 A/D 转换器数:2 架构:管线 参考类型:外部, 内部 电压 - 电源,模拟:1.7 V ~ 1.9 V 电压 - 电源,数字:1.7 V ~ 1.9 V 特性:同步采样 工作温度:-40°C ~ 85°C 封装/外壳:64-VFQFN 裸露焊盘,CSP 供应商器件封装:64-LFCSP-VQ(9x9) 标准包装:750