ADI ADF4355微波宽带(54－6800 MHz)频率合成器解决方
案
ADI公司的ADF4355是微波宽带(54-6800MHz)可实现小数N分频或整数N分频锁相环(PLL)的频率合成器,高分辨率38位模数,低相位噪声电压控制振荡器(VCO),可编程
1/2/4/8/16/32/64分频输出,模拟和数字电源为3.3 V,主要用在无线基础设施
（W-CDMA,TD-SCDMA,WiMAX,GSM, PCS,DCS,DECT）,点到点/点到多点微波链路,卫星/VSAT ,测试设备/仪器仪表和时钟产生.本文介绍了ADF4355主要特性,框图和几种应用电路,以及评估板EV-ADF4355SD1Z主要特性,电路图,材料清单和PCB设计图.
The ADF4355 allows implementation of fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers when used with an external loop filter and an external reference frequency. A series of frequency dividers permits operation from 54 MHz to 6800 MHz.
The ADF4355 has an integrated VCO with a fundamental output frequency ranging from 3400 MHz to 6800 MHz. In addition, the VCO frequency is connected to divide by 1, 2, 4, 8, 16, 32, or 64 circuits that allow the user to generate RF output frequencies as low as 54 MHz. For applications that require isolation, the RF output stage can be muted. The mute function is both pin and software controllable.
Control of all on-chip registers is through a simple 3-wire interface. The ADF4355 operates with analog and digital power supplies ranging from 3.15 V to 3.45 V, with charge pump and VCO supplies from 4.75 V to 5.25 V. The ADF4355 also contains hardware and software power-down modes.
ADF4355主要特性:
RF output frequency range: 54 MHz to 6800 MHz
Fractional-N synthesizer and integer-N synthesizer
High resolution 38-bit modulus
Low phase noise, voltage controlled oscillator (VCO)
Programmable divide by 1, 2, 4, 8, 16, 32, or 64 output
Analog and digital power supplies: 3.3 V
Charge pump and VCO power supplies: 5.0 V typical
Logic compatibility: 1.8 V
Programmable dual modulus prescaler of 4/5 or 8/9
Programmable output power level
RF output mute function
3-wire serial interface
Analog and digital lock detect
ADF4355应用:
Wireless infrastructure (W-CDMA, TD-SCDMA, WiMAX, GSM, PCS, DCS, DECT) Point to point/point to multipoint microwave links
Satellites/VSATs
Test equipment/instrumentation
Clock generation
图1.ADF4355功能框图
图2. ADF4355直接转换调制器电路图
图3. ADF4355功电源电路图
评估板EV-ADF4355SD1Z
The EV-ADF4355SD1Z evaluates the performance of the ADF4355 frequency synthesizer with integrated VCO for phase-locked loops (PLLs). A photograph of the evaluation board is shown in Figure 1. The evaluation board contains the ADF4355
frequency synthesizer with integrated VCO, a differential 122.88 MHz reference (TCXO), a loop filter, a USB interface, power supply connectors, and subminiature Version A (SMA) connectors. A USB cable is included to connect the board to a PC USB port. For easy programming of the synthesizer, download the Windows-based software
from .analog./ADF4355. This board requires an SDP-S (shown in Figure 1, but not supplied with the kit). The SDP-S allows software programming of the EV-ADF4355SD1Z device.
评估板EV-ADF4355SD1Z主要特性:
Self contained board, including ADF4355 frequency
synthesizer with integrated VCO, differential 122.88 MHz
temperature controlled crystal oscillator (TCXO), loop
filter (20 kHz), USB interface, and voltage regulators
Windows®-based software allows control of synthesizer functions from a PC
Externally powered by 6 V
图4.评估板EV-ADF4355SD1Z外形图
图5.评估板EV-ADF4355SD1Z电路图(1)
图6.评估板EV-ADF4355SD1Z电路图(2)
图7.评估板EV-ADF4355SD1Z电路图(3) 评估板EV-ADF4355SD1Z材料清单:
图8.评估板EV-ADF4355SD1Z PCB设计图(1)
图9.评估板EV-ADF4355SD1Z PCB设计图(2)
图10.评估板EV-ADF4355SD1Z PCB设计图(3)
图11.评估板EV-ADF4355SD1Z PCB设计图(4)
图12.评估板EV-ADF4355SD1Z PCB设计图(5)
图13.评估板EV-ADF4355SD1Z PCB设计图(6)。
