1 multimedia ics video signal switcher, 1 3-channel with clamped-input ba7653af the ba7653af is a video-signal switching ic that contains a three-channel clamped-input multiplexer. the inputs are sync-tip clamped (synchronous edge of the video input signals are aligned to the same voltage), and as the input impedance is extremely large, it is possible to use a small value for the clamp capacitor (the recommended capacitor is 0.01 m f (fz) ceramic). applications video cassette recorders, television and camcorders features 1) small clamp capacitors can be used (ceramic, 3000pf (min.), 0.01 m f (fs) (recommended)). 2) low supply voltage operation possible. supply volt- age range is 3.7v to 7.7v. 3) superimposition used for fast switching speed with low switching noise (70nsec. typ.). 4) low power consumption (when v cc = 5v, 25mw typ.). 5) wide dynamic range (3.1v p-p typ. for v cc = 5v). 6) excellent frequency characteristics (10mhz, 0db typ.). 7) low interchannel crosstalk ( ?70db typ.). 8) voltage can be applied to the control pins even when v cc is not applied. absolute maximum ratings (ta = 25?) parameter symbol limits unit v cc 9v mw topr c tstg c 500 * pd ?25 ~ + 75 ?55 ~ + 125 applied voltage power dissipation operating temperature storage temperature * when mounted on a 50mm 50mm board, reduced by 5mw for each increase in ta of 1 c over 25 c. recommended operating conditions (ta = 25?) parameter symbol limits unit v cc v 4.0 ~ 7.0 power supply voltage
2 multimedia ics ba7653af electrical characteristics (unless otherwise noted, ta = 25? and v cc = 5.0v) parameter symbol unit conditions min. typ. max. v cc 3.7 7.7 v i cc 2.7 5.0 8.2 ma v om 2.6 3.1 v p-p g v ?0.5 0 db c ta ?70 db g f ?3.0 0 db v th l 1.0 v v th h 2.5 45 20 (v) v cc ?v f v th = f = 1khz, thd = 1.0% f = 1mhz, v in = 1.0v p-p f = 4.43mhz, v in = 1.0v p-p f = 10mhz / 1mhz, v in = 1.0v p-p v cc ?ctl threshold level 0.5 1.0 operating voltage supply current maximum output level voltage gain interchannel crosstalk frequency characteristic ctl switching voltage guaranteed design parameters (unless otherwise noted, ta = 25? and v cc = 5.0v) parameter symbol unit conditions min. dg 0 0.5 % dp 0.5 1.0 deg typ. max. differential gain differential phase v in = 1.0v p-p , standard staircase signal v in = 1.0v p-p , standard staircase signal pin descriptions 1 in1 2 ctla 3 in2 4 ctlb 5 in3 6v cc 7out 8gnd pin no. pin name input 1 control input a input 2 control input b input 3 supply voltage output gnd function control pin truth table ctla ctlb out l l in1 h l in2 l h in3 h h in3 block diagram 1 2 3 4 8 7 6 5 in1 ctla in2 ctlb gnd out in3 logic v cc
3 multimedia ics ba7653af input / output circuits 1 in 1 1.65v 2 ctla 3 in 2 1.65v 4 ctlb 50 m a 100 in1 v cc v cc v cc v cc 2.3v 1.9v 50k ctla 50 m a 100 2.3v 1.9v 50k ctlb 50 m a pin no. in2 pin name dc voltage (v cc = 5v) input / output impedance equivalent circuit 10m w or more 10m w or more
4 multimedia ics ba7653af 50 m a 100 v cc v cc v cc v cc out 1ma gnd 5 in 3 1.65v 6v cc 5.0v 7 out 0.95v 8 gnd 0v pin no. in3 pin name dc voltage (v cc = 5v) input / output impedance equivalent circuit 10m w or more 26 w
5 multimedia ics ba7653af application examples 1 2 3 4 8 7 6 5 in1 ctla in2 ctlb gnd out v cc in3 logic logic logic v cc c. video in c. video in c. video in c. video out 0.01 m 0.01 m 0.01 m 47 m 0.1 m + when superimposition is used 1 2 3 4 8 7 6 5 in1 ctla in2 ctlb gnd out in3 logic logic logic 47 m 0.1 m v cc v cc dc1.7v or more dc1.7v or more c. video or dc out c. video in 0.01 m fig. 1 + operation notes (1) to ensure stable clamp operation, the output impedance of the previous stage connected to the inputs should be 1k w or lower. (2) if large input clamp capacitors are used, the time constant of the circuit will mean that some time will be required until stable operation after power is applied. the value for the input clamp capacitors is 0.1 m f max. (0.01 m f (fz) ceramic capacitor recommended). (3) the ba7653af is a three-channel multiplexer, but two-channel operation is also possible. in this case, if the unused input is left open it will oscillate, but this will not effect the other inputs and cause problems. if this is a concern, ground the unused input via a capacitor, or connect it directly to v cc . (4) if control inputs are left open they will be unstable, set to h or l. (5) when using superimposition, the dc voltage direct- ly applied to the inputs should be at least 1.7v.
6 multimedia ics ba7653af external dimensions (units: mm) sop8 0.4 0.1 1.27 0.15 0.3min. 0.15 0.1 0.11 6.2 0.3 4.4 0.2 5.0 0.2 85 4 1 1.5 0.1
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