- 您现在的位置：买卖IC网 > PDF目录9090 > LTC6945IUFD#PBF (Linear Technology)IC SYNTHESIZER INTEGER N 28QFN PDF资料下载
参数资料
| 型号： | LTC6945IUFD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 2/28页 |
| 文件大小： | 0K |
| 描述： | IC SYNTHESIZER INTEGER N 28QFN |
| 软件下载： | PLLWizard™ PLLWizard™, with .NET 2.0 installer |
| 标准包装： | 73 |
| 类型： | * |
| PLL： | 是 |
| 输入： | 时钟 |
| 输出： | 时钟 |
| 电路数： | 1 |
| 比率 - 输入:输出： | 1:1 |
| 差分 - 输入:输出： | 是/是 |
| 频率 - 最大： | 6GHz |
| 除法器/乘法器： | 是/无 |
| 电源电压： | 3.15 V ~ 5.25 V |
| 工作温度： | -40°C ~ 105°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-QFN（4x5） |
| 包装： | 管件 |
第1页当前第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LTC6945
10
6945f
OPERATION
Figure 1. Simplified REF Interface Schematic
Figure 2. Simplified REFO Interface Schematic
The LTC6945 is a high performance PLL, and, combined
with an external high performance VCO, can produce low
noise LO signals up to 6GHz. It is able to achieve superior
integrated phase noise performance due to its extremely
low in-band phase noise performance.
REFERENCE INPUT BUFFER
The PLL’s reference frequency is applied differentially on
pins REF+ and REF–. These high impedance inputs are
self-biased and must be AC-coupled with 470pF capacitors
(see Figure 1 for a simplified schematic). Alternatively, the
inputs may be used single-ended by applying the refer-
ence frequency at REF+ and bypassing REF– to GND with
a 470pF capacitor.
Table 1. FILT[1:0] Programming
FILT[1:0]
fREF
3
<20MHz
2NA
1
20MHz to 50MHz
0
>50MHz
Table 2. BST Programming
BST
VREF
1
<2.0VP-P
0
≥2.0VP-P
REFERENCE OUTPUT BUFFER
The reference output buffer produces a low noise square
wave with a noise floor of –155dBc/Hz (typical) at 10MHz.
Its output is low impedance, and produces 2dBm typical
output power into a 50Ω load at 10MHz. Larger output
swings will result if driving larger impedances. The out-
put is self-biased, and must be AC-coupled with a 22nF
capacitor (see Figure 2 for a simplified schematic). The
buffer may be powered down by using bit PDREFO found
in the serial port Power register h02.
27
28
4.2k
REF+
REF–
BST
FILT[1:0]
LOWPASS
4.2k
6945 F01
1.9V
BIAS
VREF
+ VREF+
A high quality signal must be applied to the REF± inputs
as they provide the frequency reference to the entire PLL.
To achieve the part’s in-band phase noise performance,
apply a CW signal of at least 6dBm into 50Ω, or a square
wave of at least 0.5VP-P with slew rate of at least 40V/μs.
Additional options are available through serial port register
h08 to further refine the application. Bits FILT[1:0] control
the reference input buffer’s lowpass filter, and should be
set based upon fREF to limit the reference’s wideband
noise. The FILT[1:0] bits must be set correctly to reach
the LM(NORM) normalized in-band phase noise floor. See
Table 1 for recommended settings.
The BST bit should be set based upon the input signal level
to prevent the reference input buffer from saturating. See
Table 2 for recommended settings and the Applications
Information section for programming examples.
2
REFO
VREFO
+
800Ω
6945 F02
REFERENCE (R) DIVIDER
A 10-bit divider, R_DIV, is used to reduce the frequency
seen at the PFD. Its divide ratio R may be set to any
integer from 1 to 1023, inclusive. Use the RD[9:0] bits
found in registers h03 and h04 to directly program the R
divide ratio. See the Applications Information section for
the relationship between R and the fREF, fPFD, fVCO and
fRF frequencies.
相关PDF资料 |
PDF描述 |
|---|---|
| X9409WV24T1 | IC XDCP QUAD 64-TAP 10K 24-TSSOP |
| V150A3V3H200B | CONVERTER MOD DC/DC 3.3V 200W |
| X9410YS24I-2.7 | IC XDCP DUAL 64-TAP 2.5K 24-SOIC |
| X9410YS24I | IC XDCP DUAL 64-TAP 2.5K 24-SOIC |
| X9410YS24-2.7 | IC XDCP DUAL 64-TAP 2.5K 24-SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC6946-1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:30MHz to 1.4GHz IQ Demodulator |
| LTC6946-2 | 制造商:LINER 制造商全称:Linear Technology 功能描述:30MHz to 1.4GHz IQ Demodulator |
| LTC6946-3 | 制造商:LINER 制造商全称:Linear Technology 功能描述:30MHz to 1.4GHz IQ Demodulator |
| LTC6946IUFD-1#PBF | 功能描述:IC INTEGER-N PLL W/VCO 28-QFN RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 时钟发生器，PLL，频率合成器 系列:- 标准包装:2,000 系列:- 类型:PLL 频率合成器 PLL:是 输入:晶体 输出:时钟 电路数:1 比率 - 输入:输出:1:1 差分 - 输入:输出:无/无 频率 - 最大:1GHz 除法器/乘法器:是/无 电源电压:4.5 V ~ 5.5 V 工作温度:-20°C ~ 85°C 安装类型:表面贴装 封装/外壳:16-LSSOP（0.175"，4.40mm 宽） 供应商设备封装:16-SSOP 包装:带卷 (TR) 其它名称:NJW1504V-TE1-NDNJW1504V-TE1TR |
| LTC6946IUFD-1#TRPBF | 功能描述:IC INTEGER-N PLL W/VCO 28QFN RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 时钟发生器，PLL，频率合成器 系列:- 标准包装:1,000 系列:Precision Edge® 类型:时钟/频率合成器 PLL:无 输入:CML，PECL 输出:CML 电路数:1 比率 - 输入:输出:2:1 差分 - 输入:输出:是/是 频率 - 最大:10.7GHz 除法器/乘法器:无/无 电源电压:2.375 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:16-VFQFN 裸露焊盘，16-MLF? 供应商设备封装:16-MLF?（3x3） 包装:带卷 (TR) 其它名称:SY58052UMGTRSY58052UMGTR-ND |
发布紧急采购，3分钟左右您将得到回复。