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 ■ 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 ■ SO-14 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 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 Ω 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 Absolute maximum ratings and operating conditions TSH345 1 Absolute maximum ratings and operating conditions Table 1. Absolute maximum ratings Symbol Parameter VCC Supply voltage (1) Vin Input voltage range Value Unit 6 V 2.5 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 SO-14 TSSOP14 22 32 °C/W Rthja Thermal resistance junction to ambient area SO-14 TSSOP14 125 110 °C/W Pmax Maximum power dissipation (at Tamb = 25° C) for Tj = 150° C SO-14 TSSOP14 1 1.1 W ESD CDM: charged device model HBM: human body model MM: machine model 250 2 100 V kV V Tj 1. All voltage values, except differential voltage, are with respect to network terminal. Table 2. Operating conditions Symbol VCC Parameter Power supply voltage 1. Tested in full production with +5 V single power supply. 2/23 Value 4.5 to 5.5(1) Unit 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 100 240 310 440 mV 1.3 1.4 3.6 µA DC performance VDC Output DC shift RL = 150 Ω, Tamb -40° C < Tamb < +85° C Iib Input bias current Tamb , input to GND -40° C < Tamb < +85° C Rin Input resistance, Tamb Cin ICC G 1 MΩ Input capacitance, Tamb 0.1 pF Total supply current (3 x operators) No load, input to GND -40°C < Tamb < +85°C 44.6 45 51.6 mA 1.96 2 1.96 2.05 V/V 3.4 3.9 3.8 V 47 mV DC voltage gain RL = 150Ω, Vin = 1.4V -40°C < Tamb < +85°C Output characteristics VOH High level output voltage RL = 150 Ω -40° C < Tamb < +85° C VOL Low level output voltage RL = 150 Ω Iout Isource Tamb -40° C < Tamb < +85° C 76 100 91 mA Isink -40° C < Tamb < +85° C 106 134 126 mA Filtering Standard definition Bandwidth F1 selected, small signal, VICM= 0.5 V, RL = 150 Ω -3 dB bandwidth -1 dB bandwidth Attenuation F1 selected/F=27 MHz, small signal, VICM = 0.5 V, RL = 150 Ω 5 9 5.7 40 45 MHz dB 3/23 Electrical characteristics Table 3. TSH345 Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C (unless otherwise specified) (continued) Symbol Test conditions Bandwidth F2 selected, small signal, VICM = 0.5 V, RL = 150 Ω -3 dB bandwidth -1 dB bandwidth Standard definition with progressive Attenuation scanning F2 selected/F = 54 MHz, small signal, VICM = 0.5 V, RL = 150 Ω High definition Bandwidth F3 selected, small signal, VICM = 0.5 V, RL = 150 Ω -3 dB bandwidth -1 dB bandwidth Attenuation F3 selected/F = 74.25 MHz, small signal, VICM = 0.5 V, RL = 150 Ω Min. Typ. Max. Unit 13 21 18 32 38 25 36 32 25 32 dB MHz dB MHz D Delay between each channel 0.5 ns gd Group delay variation F1 selected/F = 0 to 6 MHz 11 ns Δg Differential gain F1 selected/F = 6 MHz, RL = 150 Ω 0.38 % ΔΦ Differential phase F1 selected/F = 6 MHz, RL = 150 Ω 0.5 ° Total input voltage noise in Standard Definition F = 100 kHz, RIN = 50 Ω 74 Total input voltage noise in High Definition F = 100 kHz, RIN = 50 Ω 86 Noise eN nV/√Hz Standby mode ISTBY Total current consumption in standby mode Fs1 = 1, Fs0 = 1 Tamb -40° C < Tamb < +85° C 440 480 690 µA Ton Time from standby to active mode 5 µs Toff Time from active to standby mode 5 µs Fs1, Fs0 and Mux features 4/23 Vhigh High level Vlow Low level 0.9 V 0.3 V TSH345 Electrical characteristics Table 4. Filter and standby settings, VCC = +5 V single supply, Tamb = 25°C (1) Fs0(1) Fs1 Settings 0 0 F3 Filtering for high definition (HD) 0 1 F2 Filtering for progressive video (PV) 1 0 F3 Filtering for standard definition (SD) 1 1 Standby TSH345 in standby mode 1. Fs1 and Fs0 pins must never be left floating. Table 5. Mux settings, VCC = +5 V single supply, Tamb = 25°C (1) Mux Settings 0 R1 G1 B1 Video1 selected 1 R2 G2 B2 Video2 selected 1. The MUX pin must never be left floating. 5/23 Electrical characteristics Figure 1. TSH345 Filtering Figure 2. 10 6.2 6.0 HD Filter response (dB) Filter response (dB) 0 -10 PV -20 SD -30 -40 Gain flatness 5.8 HD SD 5.4 Vcc=5V small signal Load=150Ω -50 1M PV 5.6 Vcc=5V small signal Load=150 Ω 5.2 10M 100M 1M Frequency (Hz) Figure 3. Distortion 1 MHz (HD) Figure 4. 0 -20 HD2 & HD3 (dBc) -30 Vcc=5V F=1MHz HD filter Load=150 Ω -10 -20 -40 -50 -60 Distortion 10 MHz (HD) 0 HD2 & HD3 (dBc) -10 HD2 -70 -80 -30 Vcc=5V F=10MHz HD filter Load=150 Ω -40 -50 HD2 -60 -70 -80 HD3 HD3 -90 -90 -100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 -100 0.0 4.0 0.5 1.0 Output Amplitude (Vp-p) Figure 5. -20 Distortion 1 MHz (PV) Figure 6. -10 -20 HD2 & HD3 (dBc) HD2 & HD3 (dBc) -40 -50 HD2 -70 -80 -30 -40 3.0 3.5 4.0 3.0 3.5 4.0 Distortion 10 MHz (PV) Vcc=5V F=10MHz PV filter Load=150 Ω HD2 -60 -70 -80 HD3 -90 0.5 1.0 1.5 2.0 2.5 Output Amplitude (Vp-p) 6/23 2.5 -50 HD3 -90 -100 0.0 2.0 0 Vcc=5V F=1MHz PV filter Load=150 Ω -30 -60 1.5 Output Amplitude (Vp-p) 0 -10 10M Frequency (Hz) 3.0 3.5 4.0 -100 0.0 0.5 1.0 1.5 2.0 2.5 Output Amplitude (Vp-p) TSH345 Electrical characteristics Figure 7. Distortion 1 MHz (SD filter) Figure 8. 0 HD2 & HD3 (dBc) -20 -30 1000 Vcc=5V F=1MHz SD filter Load=150 Ω -40 -50 HD2 -60 Vcc=5V No load HD Input Noise (nV/VHz) -10 Input noise vs. frequency -70 PV SD 100 -80 HD3 -90 -100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 100 Output Amplitude (Vp-p) Figure 9. 10k 100k 1M Frequency (Hz) Gain vs. input amplitude Figure 10. Channel crosstalk vs. frequency 2.10 -40 Vcc=5V Load=150Ω -45 2.05 -50 X-Talk (dB) Gain (V/V) 1k 2.00 Input: 1Vp-p HD filter Vcc=5V Load=150Ω -55 -60 -65 1.95 -70 1.90 0.0 0.2 0.4 0.6 0.8 1.0 1.2 -75 1M 1.4 10M Vin (Vp-p) Figure 11. Output vs input amplitude Figure 12. MUX isolation 5.0 4.5 -40 Vcc=5V Load=150Ω -45 4.0 MUX isolation (dB) VOH 3.5 Vout (V) 100M Frequency (Hz) 3.0 2.5 2.0 1.5 Input: 1Vp-p Vcc=5V Load=150Ω -50 -55 -60 -65 1.0 -70 0.5 Output DCshift 0.0 0.0 0.2 0.4 0.6 0.8 1.0 Vin (V) 1.2 1.4 1.6 1.8 2.0 -75 1M 10M 100M Frequency (Hz) 7/23 Electrical characteristics TSH345 Figure 13. Current consumption vs. supply Figure 14. Supply current vs. temperature Vcc=5V no Load 50 49 40 Vcc=5V no Load 47 30 ICC (mA) Icc (mA) 48 20 46 45 44 43 10 42 41 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 40 -40 Vcc (V) -20 0 20 40 60 80 Temperature (°C) Figure 15. Filtering vs. temperature Figure 16. Filter attenuation vs. temperature 40 60 Vcc=5V Load=150Ω Vcc=5V Load=150Ω 55 HD 30 25 20 PV 15 50 Attenuation (dB) -1dB Bandwidth (MHz) 35 10 SD, f=27MHz 45 PV, f=54MHz 40 35 HD, f=74.25MHz 30 5 25 SD 0 -40 -20 0 20 40 60 20 -40 80 -20 Temperature (°C) 0 20 40 60 80 Temperature (°C) Figure 17. Gain matching vs. temperature Figure 18. Output DC shift vs. temperature 5 400 Vcc=5V Load=150 Ω 375 350 4 Vcc=5V Load=150Ω DCshift (mV) 325 MG (%) 3 2 300 275 250 225 200 175 1 150 125 0 -40 -20 0 20 40 Temperature (°C) 8/23 60 80 100 -40 -20 0 20 40 Temperature (°C) 60 80 TSH345 Electrical characteristics Figure 19. Standby current vs. temperature Figure 20. Isink vs. temperature 150 180 Vcc=5V no Load 140 130 120 160 Isink (mA) Istandby (µA) 170 150 140 110 100 90 80 70 130 60 120 -40 -20 0 20 40 60 Vcc=5V 50 -40 80 -20 0 Temperature (°C) Figure 21. 20 40 60 80 60 80 60 80 Temperature (°C) Isource vs. temperature Figure 22. Ibias vs. temperature 2.0 120 1.8 Vcc=5V 110 1.6 1.4 90 IBIAS (μA) Isource (mA) 100 80 1.2 1.0 0.8 0.6 70 0.4 60 0.2 Vcc=5V 50 -40 -20 0 20 40 60 0.0 -40 80 -20 Temperature (°C) 0 20 40 Temperature (°C) Figure 23. VOL vs. temperature Figure 24. VOH vs. temperature 4.00 60 3.95 55 3.90 3.85 VOH (V) VOL (mV) 50 45 3.80 3.75 40 3.70 35 30 -40 Vcc=5V Load=150Ω -20 3.65 0 20 40 Temperature (°C) 60 80 3.60 -40 Vcc=5V Load=150Ω -20 0 20 40 Temperature (°C) 9/23 Electrical characteristics TSH345 Figure 25. Gain vs. temperature 2.20 2.15 Gain (dB) 2.10 2.05 2.00 1.95 1.90 1.85 1.80 -40 Vcc=5V Load=150Ω -20 0 20 40 Temperature (°C) 10/23 60 80 TSH345 2.1 Electrical characteristics Power supply considerations: improving the power supply noise rejection Correct power supply bypassing is very important to optimize performance in low- and highfrequency 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 10 µF is necessary to improve the PSRR in low frequencies. For better quality bypassing, you can add a capacitor of 100 nF (CHF). CHF must be placed as close as possible to the IC pin to improve the noise supply rejection in the higher frequencies. A coil can be added in order to better reject the noise from the supply and to prevent current peaks as much as possible. Figure 26. Circuit for power supply bypassing +VCC Coil CLF + CHF 7 R G TSH345 B 8 AM00816 11/23 Electrical characteristics TSH345 Figure 27. Circuit for noise rejection improvement measurement S R +5 V T-bias + Coil CLF AGILENT 4395A CHF 50 7 A TSH345 50 7 AM00817 Figure 28 shows how the power supply noise rejection evolves according to the frequency and depending on how carefully power supply decoupling is achieved. Figure 28. Power supply noise rejection 0 Noise rejection ratio (dB) -10 -20 Vcc=5V(dc)+0.2Vp-p(ac) Decoupling capacitor: 10µF+100nF Load=150Ω Noise rejection=20 log (ΔVCC/ΔVout) -30 no coil -40 -50 -60 -70 -80 10k coil=560µH 100k 1M Frequency (Hz) 12/23 10M 100M TSH345 3 Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components Figure 29. Implementation of the video driver on output video DACs +5 V Y Video DAC Reconstruction filtering 75 7 ++ LPF 75 7cable + 6 dB 1 Vpp TV 75 7 1 Vpp 2 Vpp Pb Video DAC Reconstruction filtering 75 7 ++ LPF 75 7cable + 6 dB 0.7 Vpp 75 7 0.7 Vpp 0. 1.4 Vpp 1. Pr Video DAC Reconstruction filtering LPF 75 7 ++ + 6 dB 75 7cable 0.7 Vpp 75 7 0.7 Vpp 0. TSH345 1.4 Vpp 1. GND -5 V AM00818 13/23 Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components TSH345 Figure 30. Synchronization details (example for a black picture) 54 ns (4t) 27 ns (2t) 27 ns (2t) 590 ns (44 t) HD •Fclock=74.25 MHz •t=1/Fclock=13.5 ns 300 mV Black (30IRE) 300 mV 14.8 us (110 0t): 1920/1080i 24.3 us (180 0t): 1280/720i 590 ns (44 t) GN D s yn c.t ip 160 ns 150 ns SD Black (30IRE) 64 us 300 mV 4.6 us G ND s yn c.t ip AM00819 Figure 31. HD video signal Video contents up to 30 MHz 1 Vp-p (+/- 5 %) 300 mV GND DAC’s offset (DAC’s offset on STi7200 = 28 mV) AM00820 14/23 TSH345 Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components Figure 32. Standard video signal Video contents up to 6 MHz 1.3 Vp-p (+/- 5 %) 300 mV GND DAC’s offset (DAC’s offset on STi7200 = 28 mV) AM00821 15/23 Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components TSH345 Figure 33. Flexibility of the TSH345 for SD and HD signals HD/PV/SD Y,G DAC +5V 150Ω DAC 150Ω DAC 150Ω Cable 75Ω Cable 75Ω Cable NC 75Ω Pb,B,C Pr,R,CVBS TV 75Ω NC NC TSH345 TSSOP14 SO14 75Ω 75Ω RCA SCART RCA MUX and Filter select (as defined in Table 4 and Table 5) CVBS R-G-B Y-Pb-Pr Y-C-CVBS HD/PV/SD Y,G DAC +5V 150Ω DAC Pr,R,CVBS 150Ω TV 75Ω Cable 75Ω Cable 75Ω Cable NC 75Ω Pb,B,C 150Ω DAC Y-C NC NC TSH345 TSSOP14 SO14 75Ω 75Ω MUX and Filter select (as defined in Table 4 and Table 5) The TSH345 is used to drive either high-definition video signals up to 30 MHz or progressive and interlaced standard definition video signals on 75-Ω video lines. It can drive a large panel of signals such as YC and CVBS, YUV, YPbPr and RGB, 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. Since 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. 16/23 TSH345 3.1 Using the TSH345 to drive YC, CVBS, YUV, YPbPr and RGB video components Output capacitor The output can be either DC-coupled or AC-coupled. The output can be directly connected to the line via a 75-Ω resistor (see Figure 34), or an output capacitor can be used to remove any DC components in the load. Assuming the load is 150 Ω, a coupling capacitor of 220 µF can be used to provide a very low cut-off frequency close to 5 Hz (see Figure 35). Figure 34. DC output coupling for SD, PV and HD +5V 75 7 Video DAC 75 7cable TSH345 75 7 150 7 AM00822 Figure 35. AC output coupling +5V 75 7 Video DAC TSH345 C=220 µF + 75 7 cable 75 7 150 7 CS AM00823 1. CS is 100 nF used to decrease the parasitic components of C in high frequencies. It is preferable to limit the use of this output AC-coupling to the standard definition only. 2. The 75-Ω resistor must be as close as possible to the output of the driver to minimize the effect of parasitic capacitance. 17/23 Package information 4 TSH345 Package information In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. 18/23 TSH345 4.1 Package information SO-14 package information Figure 36. SO-14 package mechanical drawing Table 6. SO-14 package mechanical data Dimensions Millimeters Inches Ref. Min. Typ. Max. Min. Max. A 1.35 1.75 0.05 0.068 A1 0.10 0.25 0.004 0.009 A2 1.10 1.65 0.04 0.06 B 0.33 0.51 0.01 0.02 C 0.19 0.25 0.007 0.009 D 8.55 8.75 0.33 0.34 E 3.80 4.0 0.15 0.15 e 1.27 0.05 H 5.80 6.20 0.22 0.24 h 0.25 0.50 0.009 0.02 L 0.40 1.27 0.015 0.05 k ddd Note: Typ. 8° (max.) 0.10 0.004 D and F dimensions do not include mold flash or protrusions. Mold flash or protrusions must not exceed 0.15 mm. 19/23 Package information 4.2 TSH345 TSSOP14 package information Figure 37. TSSOP14 package mechanical drawing Table 7. TSSOP14 package mechanical data Dimensions Ref. Millimeters Min. Typ. A Max. Min. Typ. 1.20 A1 0.05 A2 0.80 b Max. 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 4.90 5.00 5.10 0.193 0.197 0.201 E 6.20 6.40 6.60 0.244 0.252 0.260 E1 4.30 4.40 4.50 0.169 0.173 0.176 e L k aaa 1.00 0.65 0.45 L1 20/23 Inches 0.60 0.0256 0.75 0.018 1.00 0° 0.024 0.030 0.039 8° 0.10 0° 8° 0.004 TSH345 5 Ordering information Ordering information Table 8. Order codes Part number Temperature range TSH345ID TSH345IDT TSH345IPT -40°C to +85°C Package SO-14 TSSOP14 Packing Marking Tube TSH345I Tape & reel TSH345I Tape & reel TSH345I 21/23 Revision history 6 TSH345 Revision history Table 9. 22/23 Document revision history Date Revision Changes 29-May-2007 1 Initial release. 18-Dec-2008 2 Added curves in Chapter 2: Electrical characteristics. Added all test limits in Chapter Table 3. TSH345 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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