TSH345 Triple video buffer with selectable filter for HD and SD video applications Features Selectable 6th order filtering of 36 MHz, 18 MHz and 9 MHz SO-14 5 V single-supply operation Internal input DC level shifter No input capacitor required TSSOP14 3 matched 6 dB amplifiers AC or DC output-coupled Fs0 Very low harmonic distortion 1 14 R1 in 36MHz 18MHz 6dB + Specified for 150 loads 9MHz LPF 13 Fs1 R2 in 2 Data min. and max. are tested during production 12 R out G1 in 36MHz 3 18MHz 6dB + 9MHz Applications LPF G2 in 4 11 G out High-end video systems 10 B out B1 in 5 36MHz High definition TV (HDTV) 18MHz + 6dB 9MHz Broadcast and graphic video LPF B2 in 6 9 Mux DC Shifter Multimedia products +VCC 8 GND 7 Description The TSH345 is a triple single-supply video buffer featuring an internal gain of 6 dB and selectable filtering for HD and SD video outputs on 75 video lines. The TSH345 is ideal to drive YC, CVBS, YUV, YPbPr or RGB signals from video DAC outputs. The main advantage of this circuit is its input DC level shifter. It allows driving video signals on 75 video lines without damaging the synchronization tip and without input or output capacitors when using a single 5 V power supply. The DC level shifter is internally fixed and optimized to keep the output video signals between low and high output rails in the best position for the greatest linearity. The TSH345 is available in SO-14 and TSSOP-14 plastic packages for optimum space saving. December 2008 Rev 1 1/23 www.st.com 23 MUX MUX MUXAbsolute maximum ratings and operating conditions TSH345 1 Absolute maximum ratings and operating conditions Table 1. Absolute maximum ratings Symbol Parameter Value Unit (1) V Supply voltage 6V CC V Input voltage range 2.5 V in T Operating free air temperature range -40 to +85 C oper T Storage temperature -65 to +150 C stg T Maximum junction temperature 150 C j Thermal resistance junction to case R C/W SO-14 22 thjc 32 TSSOP14 Thermal resistance junction to ambient area R C/W SO-14 125 thja TSSOP14 110 Maximum power dissipation (at T =25 C) for T = 150 C amb j P W SO-14 1 max TSSOP14 1.1 CDM: charged device model V 250 2 ESD HBM: human body model kV 100 MM: machine model V 1. All voltage values, except differential voltage, are with respect to network terminal. Table 2. Operating conditions Symbol Parameter Value Unit (1) V Power supply voltage 4.5 to 5.5 V CC 1. Tested in full production with +5 V single power supply. 2/23