Linear LTM9002 14位双路IF接收方案

Linear 公司的LTM9002是14位双路IF接收器子系统,包括两个高速14位ADC,匹配网络,抗混淆滤波器和两个低噪音差分放大器.能对高达300MHz的宽动态范围的IF信号进行数字化. 低噪音差分放大器的固定增益为8dB, 14dB, 20dB 或26dB,输入阻抗为50欧姆,200欧姆或400欧姆,输入到140MHz的SNG为66dB,SFDR为76dB.主要应用在电信,直接变换接收器,蜂窝基站.本文介绍了LTM9002的主要特性,方框图以及双路IF接收器方框图.

The LTM9002 is a 14-bit dual-channel IF receiver subsystem. Utilizing an integrated system in a package (SiP) technology, it includes a dual high-speed 14-bit A/D converter,matching network, anti-aliasing filter and two low noise, differential amplifiers. It is designed for digitizing wide dynamic range signals with an intermediate frequency (IF) up to 300MHz. The amplifiers allow either AC- or DC coupled input drive. Lowpass or bandpass filter networks can be implemented with various bandwidths. Contact Linear Technology regarding customization.

The LTM9002 is perfect for demanding communications applications, with AC performance that includes 66dB SNR and 76dB spurious free dynamic range (SFDR). Auxiliary DACs allow gain balancing between channels.

A single 3V supply allows low power operation. A separate output supply allows the outputs to drive 0.5V to 3.3V logic.

An optional multiplexer allows both channels to share a digital output bus. Two single-ended CLK inputs can be driven together or independently. An optional clock duty
cycle stabilizer allows high performance at full speed for a wide range of clock duty cycles.

主要特性:

Integrated Dual 14-Bit, High-Speed ADC, Passive Filters and Fixed Gain Differential Amplifiers

Up to 300MHz IF Range Lowpass and Bandpass Filter Versions

Integrated Low Noise, Low Distortion Amplifiers

Fixed Gain: 8dB, 14dB, 20dB or 26dB

50Ω, 200Ω or 400Ω Input Impedance

Integrated Bypass Capacitance, No External Components Required

66dB SNR Up to 140MHz Input (LTM9002-AA)

76dB SFDR Up to 140MHz Input (LTM9002-AA)

Auxilliary 12-Bit DACs for Gain Adjustment

Clock Duty Cycle Stabilizer

Single 3V to 3.3V Supply

Low Power: 1.3W (665mW/ch.)

Shutdown and Nap Modes

15mmx11.25mm LGA Package

应用:

Telecommunications

Direct Conversion Receivers

Main and Diversity Receivers

Cellular Base Stations



图1.LTM9002功能方框图(仅显示一路)



图2.双路IF接收器方框图