TSH345 Triple video buffer with selectable filter for HD and SD video applications Preliminary Data Features Selectable 6th order filtering of 36 MHz, 18 MHz and 9 MHz ■ 5 V single-supply operation ■ Internal input DC level shifter ■ No input capacitor required ■ 3 matched 6 dB amplifiers ■ AC or DC output-coupled ■ Very low harmonic distortion ■ Specified for 150 Ω loads TSSOP14 R1 in 1 R2 in 2 Data min. and max. are tested during production G1 in 3 MUX ■ SO14 MUX ■ Applications High-end video systems ■ High definition TV (HDTV) ■ Broadcast and graphic video ■ Multimedia products B1 in 5 MUX ■ G2 in 4 B2 in 6 36MHz 18MHz 9MHz LPF 36MHz 18MHz 9MHz LPF 36MHz 18MHz 9MHz LPF 14 Fs0 + 6dB 13 Fs1 12 R out + 6dB 11 G out 10 B out + 6dB 9 Mux DC Shifter +VCC 7 8 GND 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 Ω video lines. The TSH345 is ideal to drive either Y-C, CVBS, Y-U-V, Y-Pb-Pr or R-G-B signals from video DAC outputs. The TSH345 is available in the SO14 plastic package for optimum space-saving. The main advantage of this circuit is its input DC level shifter. It allows you to drive video signals on 75 Ω video lines without damage to the synchronization tip, and without either input or output capacitor while 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. May 2007 Rev 1 This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice. 1/14 www.st.com 14 Absolute maximum ratings and operating conditions TSH345 1 Absolute maximum ratings and operating conditions Table 1. Absolute maximum ratings (AMR) Symbol VCC Vin Parameter Supply voltage (1) Input voltage range (2) Value Unit 6 V TBD V Toper Operating free air temperature range -40 to +85 °C Tstg Storage temperature -65 to +150 °C Maximum junction temperature 150 °C Rthjc Thermal resistance junction to case SO14 TSSOP14 22 32 °C/W Rthja Thermal resistance junction to ambient area SO14 TSSOP14 125 110 °C/W Pmax Maximum power dissipation (@Tamb = 25°C) for Tj = 150° C SO14 TSSOP14 1 1.1 W ESD CDM: charged device model HBM: human body model MM: machine model 200 2 200 V kV V Tj 1. All voltage values, except differential voltage, are with respect to network terminal. 2. The magnitude of input and output voltage must never exceed VCC +0.3 V. Table 2. Operating conditions Symbol VCC Parameter Power supply voltage 1. Tested in full production with +5 V single power supply. 2/14 Value Unit 4.5 to 5.5(1) V TSH345 2 Electrical characteristics Electrical characteristics Table 3. Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C (unless otherwise specified) Symbol Test conditions Min. Typ. Max. Unit DC performance VDC Output DC shift RL = 150 Ω, Tamb -40° C < Tamb < +85° C 197 329 405 389 mV Iib Input bias current Tamb , input to GND -40° C < Tamb < +85° C 0.85 1.5 2.38 2.9 µA Rin Input resistance, Tamb 12.6 GΩ Cin Input capacitance, Tamb 0.1 pF ICC Total supply current No load, input to GND -40°C < Tamb < +85°C 50.7 TBD PSRR G Power supply rejection ratio 20 log (ΔVout/ΔVCC) Input to GND, RL = 150 Ω ΔVCC : 100 mVp/F = 1 MHz, CLF = 470 nF, CHF = 100 µF DC voltage gain RL = 150Ω, Vin = 0.5V -40°C < Tamb < +85°C 65 -70 1.94 mA dB 1.99 2 2.02 V/V DG Variation of the DC voltage gain between inputs of 0.3 V and 1 V Input step from 0.3 V to 1 V 0.2 0.5 % MG1 Gain matching between 3 channels, input = 1 V 0.5 1 % Gain matching between 3 channels, input = 0.3 V 0.5 1 % MG0.3 Output characteristics VOH High level output voltage RL = 150 Ω -40° C < Tamb < +85° C VOL Low level output voltage(1) RL = 150 Ω -40° C < Tamb < +85° C Iout 3.84 3.87 TBD 33 TBD V 40 mV 91 Isource Tamb -40° C < Tamb < +85° C 46 Isink -40° C < Tamb < +85° C TBD mA 79 145 102 mA 3/14 Electrical characteristics Table 3. Symbol TSH345 Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C (unless otherwise specified) (continued) Test conditions Min. Typ. 5.12 9.3 7.3 Max. Unit Filtering Bandwidth F1 selected, small signal, VICM= 0.5 V, RL = 150 Ω 3 dB bandwidth 1 dB bandwidth Standard definition Flatness F1selected/F= 6 MHz, small signal, VICM = 0.5 V, RL = 150 Ω Attenuation F1 selected/F=27 MHz, small signal, VICM = 0.5 V, RL = 150 Ω Bandwidth F2 selected, small signal, VICM = 0.5 V, RL = 150 Ω 3 dB bandwidth 1 dB bandwidth Standard definition Flatness with progressive F2 selected/F=12 MHz small signal, VICM = 0.5 V, scanning RL = 150 Ω Attenuation F2 selected/F=54 MHz, small signal, VICM = 0.5 V, RL = 150 Ω Bandwidth F3 selected, small signal, VICM = 0.5 V, RL = 150 Ω 3 dB bandwidth 1 dB bandwidth High definition 4/14 0.5 dB 30 47 dB 10.4 21.5 18.2 MHz 0.36 dB 34 42.7 dB 22 35.6 30.8 Flatness F3 selected/F=30 MHz, small signal, VICM = 0.5 V, RL = 150 Ω Attenuation F3 selected/F=74.25 MHz, small signal, VICM = 0.5 V, RL = 150 Ω MHz TBD MHz 0.46 dB 36 dB D Delay between each channel 0.5 ns gd Group delay variation F1 selected/F=0 to 6 MHz 10.3 ns Δg Differential gain F1 selected/F=6 MHz, RL = 150 Ω 0.5 % ΔΦ Differential phase F1 selected/F=6 MHz, RL = 150 Ω 0.5 ° TSH345 Electrical characteristics Table 3. Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C (unless otherwise specified) (continued) Symbol Test conditions Min. Typ. Max. Unit Noise and distortion Total input voltage noise in Standard Definition F = 100 kHz, RIN = 50 Ω 70 Total input voltage noise in High Definition F = 100 kHz, RIN = 50 Ω 93 HD2 2nd harmonic distortion F1 selected/F=1 MHz, Vout = 2 Vp-p, RL = 150 Ω -44 dBc HD3 3rd harmonic distortion F1 selected/F=1 MHz, Vout = 2 Vp-p, RL = 150 Ω -63 dBc eN nV/√Hz Standby mode Total current consumption in standby mode Fs1=1, Fs0=1 ISTBY TBD 570 µA Ton Time from standby to active mode 5 µs Toff Time from active to standby mode 5 µs Fs1, Fs0 and Mux features Vhigh High level Vlow Low level 0.9 V 0.3 V 1. Simulated data. Table 4. Filter and standby settings, VCC = +5 V single supply, Tamb = 25°C Fs1 Fs0 Settings 0 0 F3 Filtering for high definition (HD), 36 MHz 0 1 F2 Filtering for progressive video (PV), 18 MHz 1 0 F1 Filtering for standard definition (SD), 9 MHz 1 1 Standby TSH345 in standby mode Fs1 and Fs0 floating: forbidden (for proper behavior of the TSH345, the Fs1 and Fs0 pins must never be left floating) Table 5. Mux settings, VCC = +5 V single supply, Tamb = 25°C Mux Settings 0 R1 G1 B1 Video1 selected 1 R2 G2 B2 Video2 selected Floating R1 G1 B1 Video1 selected MUX floating: forbidden (for proper behavior of the TSH345, the MUX pin must never be left floating) 5/14 Power supply considerations 3 TSH345 Power supply considerations Correct power supply bypassing is very important for optimizing performance in low and high-frequency ranges. Bypass capacitors should be placed as close as possible to the IC pin (pin 4) to improve high-frequency bypassing. A capacitor (CLF) greater than 100 µF is necessary to improve the PSRR in low frequencies. For better quality bypassing, you can add a capacitor of 470 nF (CHF), also placed as close as possible to the IC pin, to improve the PSRR in the higher frequencies. Figure 1. Circuit for power supply bypassing +VCC CLF + CHF 4 R in G in B in TSH345 5 6/14 R out G out B out TSH345 4 Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components Figure 2. Implementation of the video driver on output video DACs +5V Video DAC Reconstruction Filtering Y +6dB + LPF 75Ω 75Ω Cable 1Vpp TV 75Ω 1Vpp 2Vpp Video DAC Pb Reconstruction Filtering +6dB + LPF 75Ω 75Ω Cable 0.7Vpp 75Ω 0.7Vpp 1.4Vpp Video DAC Reconstruction Filtering Pr +6dB + LPF 75Ω Cable 0.7Vpp 75Ω 0.7Vpp TSH345 1.4Vpp GND -5V Figure 3. 75Ω Shapes of video signals coming from DACs (example for a black picture) 54ns (4t) 27ns (2t) 590ns (44t) HD 300mV 27ns (2t) •Fclock=74.25MHz •t=1/Fclock=13.5ns 300mV Black (30IRE) 14.8us (1100t): 1920/1080i 24.3us (1800t): 1280/720i 590ns (44t) GND sync.tip 160ns 150ns SD Black (30IRE) 64us 300mV 4.6us GND sync.tip 7/14 Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components Figure 4. TSH345 Flexibility of the TSH345 for SD and HD signals HD/PV/SD Y,G DAC +5V TV 75Ω Cable 75Ω Cable 75Ω Cable 150Ω DAC 75Ω 150Ω Pb,B 150Ω DAC TSH345 150Ω Pr,R TSSOP14 SO14 150Ω 75Ω 75Ω 150Ω DAC DAC DAC Y,G Mux Filter select Standby Pb,B,C Pr,R,CVBS HD/PV/SD Y,G DAC +5V TV 75Ω 150Ω DAC DAC NC 75Ω Pb,B,C 75Ω 150Ω NC Pr,R,CVBS 150Ω Cable NC TSH345 TSSOP14 SO14 Cable 75Ω 75Ω Cable 75Ω Mux (NC) Filter select Standby The TSH345 is used to drive either high definition video signals up to 30 MHz, or progessive and interlaced standard definition video signals on 75-ohm video lines. It can drive a large panel of signals like Y-C and CVBS, Y-U-V, Y-Pb-Pr and R-G-B where the bottom of the signal (the synchronization tip in the case of Y and CVBS signals) is close to zero volts. An internal input DC value is added to the video signal in order to shift the bottom from GND. The shift is not based on the average of the signal, but is an analog summation of a DC component to the video signal. Therefore, no input capacitors are required, which provides a real advantage in terms of cost and board space. Under these conditions, it is possible to drive the signal in single supply without any saturation of the driver against the lower rail. Because half of the signal is lost through output impedance matching, in order to properly drive the video line, the shifted signal is multiplied by a gain of 2 or +6 dB. 8/14 TSH345 4.1 Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components Output capacitor The output can be either DC-coupled or AC-coupled. The output can be connected to the line via a 75-ohm resistor directly (see Figure 5). Or, an output capacitor can be used to remove any DC components in the load. Assuming the load is 150-ohm, a coupling capacitor of 220 µF can be used to provide a very low cut-off frequency close to 5 Hz (see Figure 6). Figure 5. DC output coupling (1 of 3 channels) +5V 75Ω Video DAC 75Ω Cable TSH345 75Ω 150Ω Figure 6. AC output coupling (1 of 3 channels) +5V 75 Video DAC TSH345 C=220µF 75 + Cable 75 150 CS 1. CS is a 100nF used to decrease the parasitic components of C in high frequencies. 2. The 75-ohm resistor must be as close as possible to the output of the driver to minimize the effect of parasitic capacitance. 9/14 Package information 5 TSH345 Package information In order to meet environmental requirements, STMicroelectronics offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics trademark. ECOPACK specifications are available at: www.st.com. 10/14 TSH345 5.1 Package information SO-14 package Dimensions Ref. Millimeters Min. Typ. A a1 Inches Max. Min. Typ. 1.75 0.1 0.2 a2 Max. 0.068 0.003 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45° (typ.) D 8.55 8.75 0.336 0.344 E 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 7.62 0.300 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.68 0.026 8° (max.) 11/14 Package information 5.2 TSH345 TSSOP14 package Dimensions Ref. Millimeters Min. Typ. A Inches Max. Min. Max. 1.2 A1 0.05 A2 0.8 b 0.047 0.15 0.002 0.004 0.006 1.05 0.031 0.039 0.041 0.19 0.30 0.007 0.012 c 0.09 0.20 0.004 0.0089 D 4.9 5 5.1 0.193 0.197 0.201 E 6.2 6.4 6.6 0.244 0.252 0.260 E1 4.3 4.4 4.48 0.169 0.173 0.176 1 e 0.65 BSC K 0° L1 0.45 A 0.0256 BSC 8° 0° 0.60 0.75 0.018 e c 8° 0.024 0.030 A2 A1 b K E1 PIN 1 IDENTIFICATION 1 L E D 12/14 Typ. TSH345 6 Ordering infomation Ordering infomation Table 6. Order codes Temperature range Part number TSH345ID TSH345IDT -40°C to +85°C TSH345IPT 7 Package SO14 TSSOP14 Packing Marking Tube TSH345I Tape & reel TSH345I Tape & reel TSH345I Revision history Date Revision 29-May-07 1 Changes Preliminary data, initial release. 13/14 TSH345 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. 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