Maxim MAX19794 10MHz－500MHz双路模拟可变电压衰减器解决方案

Maxim公司的MAX19794是10MHz-500MHz频率的双路通用模拟可变电压衰减器(VVA),设计用于50欧姆系统,包括专用控制电路,提供22.4dB衰减,典型线性控制斜率为8dB/V.两个衰减器采用共同的确模拟控制,可以级联起来以得到44.7dB的总衰减,典型的组合线性控制斜率为16dB/V(5V工作).片上4线SPI控制的10位DAC能用来控制两个衰减器.MAX19794是单片器件,采用该公司的专有的SiGeBiCMOS工艺,工作单5V电压或+3.3V电压.器件具有高度线性度,整个衰减范围内IIP3大于+34.4dBm,输入P1dB为+21.8dBm.采用36引脚6mmx6mmx0,8mm TQFN封装,工作温度为-40NC到+100NC.主要用在宽带系统包括无线基础设备数字和扩频通信系统, WCDMA/LTE, TD-SCDMA/TD-LTE, WiMAX®, cdma2000®, GSM/EDGE和MMDS基站,VSAT/卫星地面调制解调器,微波点对点系统,温度补偿电路,自动增益控制(ALC),发送器增益控制,接收器增益控制和通用测试设备.本文介绍了MAX19794主要优势和特性,典型应用电路,以及评估板MAX19794 EVK主要特性,电路图,材料清单和PCB设计图.

The MAX19794 dual general-purpose analog voltage variable attenuator (VVA) is designed to interface with 50I systems operating in the 10MHz to 500MHz frequency range. This device includes a patented control circuit that provides 22.4dB of attenuation range (per attenuator) with a typical linear control slope of 8dB/V.

Both attenuators share a common analog control. They can be cascaded together to yield 44.7dB of total attenuation range with a typical combined linear control slope of 16dB/V (5V operation). Alternatively, the on-chip, 4-wire SPI-controlled 10-bit DAC can be used to control both attenuators. In addition, a step-up/down feature allows user-programmable attenuator stepping through command pulses without re-programming the SPI interface.

The MAX19794 is a monolithic device designed using one of Maxims proprietary SiGeBiCMOS processes. The part operates from a single +5V supply or alternatively operates from a single +3.3V supply. It is available in a compact 36-pin TQFN package (6mm x 6mm x 0.8mm) with an exposed pad. Electrical performance is guaranteed over the -40NC to +100NC extended...