- 您现在的位置：买卖IC网 > PDF目录69523 > TRF3750IRGPR (TEXAS INSTRUMENTS INC) PLL FREQUENCY SYNTHESIZER, 2400 MHz, PQCC20 PDF资料下载
参数资料
| 型号： | TRF3750IRGPR |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | PLL合成/DDS/VCOs |
| 英文描述： | PLL FREQUENCY SYNTHESIZER, 2400 MHz, PQCC20 |
| 封装： | 4 X 4 MM, GREEN, PLASTIC, QFN-20 |
| 文件页数： | 18/37页 |
| 文件大小： | 860K |
| 代理商： | TRF3750IRGPR |
第1页第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页当前第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页第33页第34页第35页第36页第37页
TRF3750
SLWS146B MARCH 2004 REVISED AUGUST 2007
www.ti.com
25
APPLICATION INFORMATION
SYNTHESIZING A SELECTED FREQUENCY
The TRF3750 is an integer-N PLL synthesizer, and because of its flexibility (14-bit R, 6-bit A, 13-bit B counter,
and dual modulus prescaler), is ideal for synthesizing virtually any desired frequency. Let us assume that we
need to synthesize a 900-MHz local oscillator, with spacing capability (minimum frequency increment) of 200
kHz, as in a typical GSM application. The choice of the external reference oscillator to be used is beyond the
scope of this section, but assuming that a 10-MHz reference is selected, we calculate the settings that yield
the desired output frequency and channel spacing. There is usually more than one solution to a specific set of
conditions, so below is one way of achieving the desired result.
First, select the appropriate R counter value. Since a channel spacing of 200 kHz is desired, the PFD can also
be set to 200 kHz. Calculate the R value through R = REFIN/PFD = 10 MHz / 200 kHz = 50. Assume a prescaler
value of 8/9 is selected. This is a valid choice, since the prescaler output will be well within the 200-MHz limit
(900 MHz / 8 = 112.5 MHz). Select the appropriate A and B counter values. We know that RFOUT = fPFD x N
= (fREFIN / R) x (A + P x B). Therefore, we need to solve the following equation:
900 MHz = 200 kHz x (A + 8 x B)
Clearly there are many solutions to this single equation with two unknowns; there are some basic constraints
on the solution, since 3 ≤ B ≤ 8191, and also B ≥ A. So, if we pick A = 4, solving the equation yields B = 562.
Thus, one complete solution would be to choose: R = 50, A = 4, B = 562, and P = 8/9, resulting in the desired
N = 4500.
The GUI software accompanying the evaluation board of the TRF3750 includes an easy Parameter Selection
Assistant that can directly propose appropriate values for all the counters given the user’s requirements. In
addition, the software can configure all the possible settings of the TRF3750 and can output the data stream
required, so that the user has a reference when programming the serial port.
To complete the example, the serial port has to be programmed in order for the correct frequency to appear
at the output of the complete PLL. Assuming that the user wanted to program the same modes as used in the
RF Performance Specifications section, a possible sequence of serial data going into the device could be the
one listed below for the three different latches (note that the initialization latch is not used in this example):
Table 10. R Counter Latch Programming Example
DB
23
DB
22
DB
21
DB
20
DB
19
DB
18
DB
17
DB
16
DB
15
DB
14
DB
13
DB
12
DB
11
DB
10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
1
0
1
0
1
0
1
0
Table 11. N Counter Latch Programming Example
DB
23
DB
22
DB
21
DB
20
DB
19
DB
18
DB
17
DB
16
DB
15
DB
14
DB
13
DB
12
DB
11
DB
10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
1
0
1
0
1
0
1
0
1
Table 12. Function Latch Programming Example
DB
23
DB
22
DB
21
DB
20
DB
19
DB
18
DB
17
DB
16
DB
15
DB
14
DB
13
DB
12
DB
11
DB
10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
1
0
1
0
1
0
1
0
1
0
相关PDF资料 |
PDF描述 |
|---|---|
| TRF3750IPW | PLL FREQUENCY SYNTHESIZER, 2400 MHz, PDSO16 |
| TRF3761-AIRHATG4 | PLL FREQUENCY SYNTHESIZER, 104 MHz, PQCC40 |
| TRF3761-EIRHAR | PLL FREQUENCY SYNTHESIZER, 104 MHz, PQCC40 |
| TRF3761-CIRHATG4 | PLL FREQUENCY SYNTHESIZER, 104 MHz, PQCC40 |
| TRF3761-JIRHATG4 | PLL FREQUENCY SYNTHESIZER, 104 MHz, PQCC40 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TRF3750IRGPRG4 | 功能描述:时钟合成器/抖动清除器 High Perf Integer-N PLL Freq Synth RoHS:否 制造商:Skyworks Solutions, Inc. 输出端数量: 输出电平: 最大输出频率: 输入电平: 最大输入频率:6.1 GHz 电源电压-最大:3.3 V 电源电压-最小:2.7 V 封装 / 箱体:TSSOP-28 封装:Reel |
| TRF3750Q1900EVM | 功能描述:射频开发工具 TRF3750Q1900 Eval Mod RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V |
| TRF3750Q2100EVM | 制造商:Texas Instruments 功能描述:TRF3750Q2100 EVAL - Bulk |
| TRF3750Q900EVM | 制造商:Texas Instruments 功能描述:TRF3750Q900 EVAL - Bulk |
| TRF3750T-1900EVM | 功能描述:射频开发工具 TRF3750T-1900 Eval Mod RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V |
发布紧急采购，3分钟左右您将得到回复。