Space saving transistors for digital and analog TV tuners
( 01 Jun 2003 )
A new generation of RF transistors, optimized to provide excellent dynamic performance and significant space savings in TVs, VCRs, set-top boxes and satellite systems has been launched by Vishay Intertechnology.
The new MOS Transistor (MOSMIC) devices include two single MOSMICs — the S505TY and S506TY—respectively optimized for UHF and VHF amplification; and a dual MOSMIC with both UHF- and VHF-optimized amplifiers, the TSDF02830Y. The three MOSMICs serve as low-noise, gain controlled input stages in digital and analog TV tuners and are specified for a supply-voltage range of 3 to 7V. They feature a high, soft-slope automatic gain control (AGC) range to minimize noise. The S505TY, S506TY and TSDF02830Y also provide easy Gate-1 switch-off with PNP switching transistors inside the PLL. Additional integrated features include gate protection diodes and a partly internal self-biasing network.
Typical forward transadmittance is 31 mS for the UHF-optimized S505TY and the UHF amplifier of the dual TSDF02830Y. Input capacitance is 1.9 pF, with a typical noise figure of 1.3 dB at 800 MHz. For the VHF-optimized S506TY and the VHF amplifier of the TSDF02830Y, typical forward transadmittance is 28 mS, with input capacitance of 2.5 pF, and a typical noise of 1.5 dB at 800 MHz.
The devices offer good cross modulation at gain reduction. At typical frequencies of fwanted = 50 MHz and funwanted = 60 MHz, k = 1% of cross modulation at 40 dB AGC (automatic gain control) is achieved for input levels up to a minimum of 100 dBmV in the UHF-optimized MOSMIC amplifiers, and up to a minimum 105 dBV in the VHF-optimized amplifiers. Packaging options for the S505TY and S506TY are the compact, surface - mount SOT143, SOT143R and SOT343R. The TSDF02830Y is available in the SOT363, SOT363R and SOT363L SMD packages which share a common outline but feature diff e rent internal pin configurations to accommodate a wider variety of applications.
A new generation of RF transistors, optimized to provide excellent dynamic performance and significant space savings in
