- 您现在的位置：买卖IC网 > PDF目录16560 > EVAL-ADF4193EBZ2 (Analog Devices Inc)BOARD EVALUATION EB2 FOR ADF4193 PDF资料下载
参数资料
| 型号： | EVAL-ADF4193EBZ2 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 3/32页 |
| 文件大小： | 0K |
| 描述： | BOARD EVALUATION EB2 FOR ADF4193 |
| 标准包装： | 1 |
| 主要目的： | 计时，频率合成器 |
| 嵌入式： | 否 |
| 已用 IC / 零件： | ADF4193 |
| 主要属性： | 400 MHz ~ 3.5 GHz，数字式可编程输出相位 |
| 次要属性： | 板不包括环路滤波器和 VCO |
| 已供物品： | 板，缆线，CD |
| 相关产品： | ADF4193BCPZ-ND - IC PLL FREQ SYNTHESIZER 32LFCSP ADF4193BCPZ-RL7-ND - IC PLL FREQ SYNTHESIZER 32LFCSP ADF4193BCPZ-RL-ND - IC PLL FREQ SYNTHESIZER 32LFCSP |
第1页第2页当前第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页第29页第30页第31页第32页
Data Sheet
ADF4193
Rev. F | Page 11 of 32
THEORY OF OPERATION
The ADF4193 is targeted at GSM base station requirements,
specifically to eliminate the need for ping-pong solutions. It
works based on fast lock, using a wide loop bandwidth during a
frequency change and narrowing the loop bandwidth once
frequency lock is achieved. Widening the loop bandwidth is
achieved by increasing the charge pump current. Switches are
included to change the loop filter component values to maintain
stability with the changing charge pump current. The narrow
loop bandwidth ensures that phase noise and spur specifications
are met. A differential charge pump and loop filter topology are
used to ensure that the fast lock time benefit from widening the
loop bandwidth is maintained when the loop is restored to
narrow bandwidth mode for normal operation.
REFERENCE INPUT SECTION
The reference input stage is shown in Figure 20. Switches S1 and
S2 are normally closed, and S3 is normally open. During power-
down, S3 is closed, and S1 and S2 are opened to ensure that
there is no loading of the REFIN pin. The falling edge of REFIN is
the active edge at the positive edge triggered PFD.
05328-016
BUFFER
TO R COUNTER
REFIN
100k
NC
S2
S3
NO
NC
S1
POWER-DOWN
CONTROL
Figure 20. Reference Input Stage
R Counter and Doubler
The 4-bit R counter allows the input reference frequency to be
divided down to produce the reference clock to the phase
frequency detector (PFD). A toggle flip-flop can be optionally
inserted after the R counter to give a further divide-by-2. Using
this option has the additional advantage of ensuring that the
PFD reference clock has a 50/50 mark-space ratio. This ratio
gives the maximum separation between the fast lock timer
clock, which is generated off the falling edge of the PFD
reference, and the rising edge, which is the active edge in the
PFD. It is recommended that this toggle flip-flop be enabled for
all even R divide values greater than 2. It must be enabled if
dividing down a REFIN frequency that is greater than 120 MHz.
An optional doubler before the 4-bit R counter can be used for
low REFIN frequencies, up to 20 MHz. With these programmable
options, reference division ratios from 0.5 to 30 between REFIN
and the PFD are possible.
RF INPUT STAGE
The RF input stage is shown in Figure 21. It is followed by a
2-stage limiting amplifier to generate the CML clock levels
needed for the prescaler. Two prescaler options are selectable: a
4/5 and an 8/9. The 8/9 prescaler is selected for N divider values
greater than 80.
05328-017
BIAS
GENERATOR
1.6V
AGND
AVDD
500
500
RFIN–
RFIN+
Figure 21. RF Input Stage
RF N Divider
The RF N divider allows a fractional division ratio in the PLL
feedback path. The integer and fractional parts of the division
are programmed using separate registers, as shown in Figure 22
and described in the INT, FRAC, and MOD Relationship
section. Integer division ratios from 26 to 255 are allowed and a
third-order, Σ-Δ modulator interpolates the fractional value
between the integer steps.
05328-
018
THIRD-ORDER
FRACTIONAL
INTERPOLATOR
FRAC
VALUE
MOD
REG
INT
REG
RF N DIVIDER
N = INT + FRAC/MOD
FROM RF
INPUT STAGE
TO PFD
N COUNTER
Figure 22. Fractional-N Divider
INT, FRAC, and MOD Relationship
The INT, FRAC, and MOD values, programmed through the
serial interface, make it possible to generate RF output frequencies
that are spaced by fractions of the PFD reference frequency.
The N divider value, shown inside the brackets of the following
equation for the RF VCO frequency (RFOUT), is made up of an
integer part (INT) and a fractional part (FRAC/MOD):
RFOUT = FPFD × [INT + (FRAC/MOD)]
where:
RFOUT is the output frequency of the external VCO.
FPFD is the PFD reference frequency.
相关PDF资料 |
PDF描述 |
|---|---|
| RMC06DRTH-S734 | CONN EDGECARD 12POS DIP .100 SLD |
| HBM18DSUN | CONN EDGECARD 36POS .156 DIP SLD |
| RSC06DREI-S734 | CONN EDGECARD 12POS .100 EYELET |
| EBA24DRMI | CONN EDGECARD 48POS .125 SQ WW |
| MAX8663ETL+T | IC PMIC LI+ SNGL CELL 40TQFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| EVAL-ADF4206-7EB1 | 制造商:Analog Devices 功能描述:EVALUATION BOARD FOR DUAL RF PLL FREQUENCY SYNTHESIZERS 制造商:Analog Devices 功能描述:DUAL RF PLL FREQ SYNTHESIZERS - Bulk |
| EVAL-ADF4208EB1 | 制造商:Analog Devices 功能描述:Evaluation Board For Dual RF PLL Frequency Synthesizers 制造商:Analog Devices 功能描述:DUAL RF PLL FREQ SYNTHESIZERS - Bulk |
| EVAL-ADF4212EB1 | 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk |
| EVAL-ADF4213EB1 | 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk |
| EVAL-ADF4213EB2 | 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk |
发布紧急采购，3分钟左右您将得到回复。