ST STV4100地面数字电视调谐方案

ST 公司的STV4100是超小型低功耗3.3V地面电视调谐器,具有正交输出的直接变换(零IF)接收器,主要用于数字电视广播.STV4100输入频率从174 到230MHz和470 到870 MHz,单电源3.3V工作,典型功耗625mW,全集成了VCO以及带RF功率监视的RF AGC,并具有谐波抑制级.它的可编程信道滤波器覆盖6-8MHz信道间隔.工作温度-10度到70度C,可用在地面电视机顶盒(STB),iDTV和PCTV.本文介绍了STV4100的主要特性,方框图和在DVB-T系统应用框图以及带与不带回路线入口的STV4100应用框图.

STV4100:Ultra-compact low-power 3.3-V terrestrial tuner IC The STV4100 terrestrial tuner is a directconversion (zero-IF) receiver with quadrature outputs intended for digital TV broadcasting.

On each VHF and UHF input is a low noise amplifier with both switchable and variable gain to ensure an optimal signal level for the two mixers.

Each mixer, which down-converts the signal to baseband, is followed by a low-pass filter and amplifier. The baseband gain is programmable via a dedicated pin.

The LO signals are provided by an integrated PLL which contains an on-chip voltage controlled oscillator meeting stringent phase noise requirements. The LO frequencies are programmable.

The comparison frequency for the phase/frequency detector is generated by dividing the crystal oscillator reference frequency. The crystal frequency can be from 16 MHz to 31 MHz depending on application.

STV4100主要特性:

RF-to-baseband direct conversion (IQ interface only)

Single 3.3-V DC supply

Input frequency range 174 to 230 MHz and 470 to 870 MHz

Fully integrated VCO

Harmonic rejection mixer stage

Fully integrated RF AGC with RF power monitoring

Programmable channel filter covers 6 to 8 MHz channel spacing

Low external component count

Low power consumption (625 mW typical)

Temperature range -10℃ to 70℃

Crystal frequency output to drive the demodulator IC

Compatible with 5-V and 3.3-V I2C bus

Fully Nordig Unified (versions 1.0.2, 1.0.3, 2.0) compliant

DTG (D-Book) compliant

Digitenne compliant

VFQFPN-32 5x5x1 mm3, exposed pad down

ECOPACK, environmentally-friendly package, RoHS (2002/95/EC) compliant.

STV4100典型应用:

Terrestrial set-top box

iDTV

PCTV



图1. STV4100方框图



图2.STV4100在DVB-T系统应用框图



图3.不带回路线入口的STV4100应用框图



图4.带回路线入口的STV4100应用简图