DEMO CIRCUIT 858 LT6555 QUICK START GUIDE LT6555 Triple High-Speed 2:1 Video MUX DESCRIPTION Demonstration circuit 858 is a Triple High-Speed 2:1 The Performance Summary table below indicates the Video MUX featuring the LT6555. This Demo Circuit operating characteristics of this demonstration circuit. provides DC-coupled 75W inputs/outputs and is in- Design files for this circuit board are available. Call tended to operate from split power supplies. The ultra the LTC factory. high bandwidth and channel-switching rate make the LT6555 ideal for HDTV and UXGA video equipment. , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT and PowerPath are trademarks of Linear Technology Corporation. PERFORMANCE SUMMARY Specifications are at T = 25C A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Split supply operation 3.3 5.0 5.5 V CC Supply Voltage(s) V Single supply operation 6 12 V EE Z Input Impedance, IN1A, IN2A, IN3A, 75 W IN DC-coupled IN1B, IN2B, IN3B Z Output Impedance, OUT1, OUT2, OUT3 DC-coupled 75 W OUT Outputs terminated into 75W 0.0 dB Gain A Outputs terminated into High impedance 6.0 dB BW Bandwidth 3dB, Small Signal 650 MHz Worst-case All Hostile, 10MHz -75 dB Crosstalk Worst-case All Hostile, 100MHz -50 dB 3.3V Split Supply, 0.7 V V No Output Clipping IN Input Signal Voltage Range 5.0V Split Supply, 1.5 V (note: feedback resistor connections tied No Output Clipping to ground on printed circuit) +9.0V Single Supply, V = 2.2V +1.0 +3.5 V REF No Output Clipping Logic Low Voltage (Amplifiers ON, Inputs -0.3 1.0 V A active), DGND = 0V V EN, Control Input Voltage 1.8 (EN) 5.5 V V Logic High Voltage (Amplifiers OFF, Inputs SEL B active), DGND = 0V 1.8 (SEL) 8 V t Select Response Time 8 ns SEL t Enable/Disable Response Time 50/500 ns EN I , I Supply Current 5.0V supply, No signal 27 mA CC EE 1 LT6555 and/or video analyzer to the outputs, using equal- 9. To evaluate the input selection feature, place the JP4 length cabling amongst the three video channels. jumper in either the A or B position to activate the Figure 2 shows a typical pulse response. appropriate input. If JP4 is in the B position, a select command signal may be furnished to SEL A/B (J8 8. To evaluate the shutdown mode, disconnect or relo- or E4) from an external source. Logic low selects cate the JP1 jumper to the EXT position (with no input-group A and logic high selects input-group B. connections made at EN (J1 or E1), or if present, a logic high provided). Power Supply ----5555....00000000 ++++5555....00000000 COM + A Inputs Outputs B Inputs Figure 1. Recommended Demo Circuit Setup 3