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 0.01µF (FZ) ceramic). Applications •Video cassette recorders, television and camcorders •1)Features Small clamp capacitors can be used (ceramic, 5) Wide dynamic range (3.1VP-P Typ. for VCC = 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 VCC is not applied. 3000pF (Min.), 0.01µF (FS) (recommended)). 2) Low supply voltage operation possible. Supply voltage 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 VCC = 5V, 25mW Typ.). •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit Applied voltage VCC 9 V Power dissipation Pd 500∗ mW Operating temperature Topr – 25 ~ + 75 °C Storage temperature Tstg – 55 ~ + 125 °C ∗ 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°C) Parameter Power supply voltage Symbol Limits Unit VCC 4.0 ~ 7.0 V 1 Multimedia ICs BA7653AF •Block diagram IN1 1 8 GND CTLa 2 7 OUT IN2 3 6 VCC 5 IN3 Logic CTLb 4 •Control pin truth table •Pin descriptions CTLa CTLb OUT Input 1 L L IN1 Control input a H L IN2 Input 2 L H IN3 Control input b H H IN3 Pin No. Pin name 1 IN1 Function 2 CTLa 3 IN2 4 CTLb 5 IN3 Input 3 6 VCC Supply voltage 7 OUT Output 8 GND GND •Electrical characteristics (unless otherwise noted, Ta = 25°C and V Parameter CC = 5.0V) Symbol Min. Typ. Max. Unit Conditions VCC 3.7 — 7.7 V — Supply current ICC 2.7 5.0 8.2 mA — Maximum output level Vom 2.6 3.1 — VP-P f = 1kHz, THD = 1.0% Voltage gain GV – 0.5 0 0.5 dB f = 1MHz, VIN = 1.0VP-P Interchannel crosstalk Cta — — dB f = 4.43MHz, VIN = 1.0VP-P Gf dB f = 10MHz / 1MHz, VIN = 1.0VP-P Operating voltage Frequency characteristic CTL switching voltage – 70 – 3.0 0 1.0 VTH L — — 1.0 VTH H 2.5 — — VCC – CTL Threshold Level VCC – VF VTH = × 20 (V) 45 V •Guaranteed design parameters (unless otherwise noted, Ta = 25°C and V CC Parameter 2 Symbol Min. Differential gain DG Differential phase DP Unit = 5.0V) Conditions Typ. Max. — 0 0.5 % VIN = 1.0VP-P, standard staircase signal — 0.5 1.0 deg VIN = 1.0VP-P, standard staircase signal Multimedia ICs BA7653AF •Input / output circuits Pin No. Pin name DC voltage (VCC = 5V) Input / output impedance Equivalent circuit VCC 1 IN 1 1.65V 10MΩ or more IN1 100 50µA VCC 2.3V 2 CTLa — — 50k CTLa 1.9V VCC 3 IN 2 1.65V 10MΩ or more IN2 100 50µA VCC 2.3V 4 CTLb — — 50µA 50k CTLb 1.9V 3 Multimedia ICs Pin No. Pin name BA7653AF DC voltage (VCC = 5V) Input / output impedance Equivalent circuit VCC 5 IN 3 1.65V 10MΩ or more IN3 100 50µA VCC 6 VCC 5.0V — VCC 7 OUT 0.95V OUT 26Ω 1mA VCC 8 GND 0V — GND 4 Multimedia ICs BA7653AF •Application examples GND IN1 C. Video In 1 8 2 7 0.01µ OUT CTLa Logic C. Video Out VCC VCC IN2 C. Video In 3 6 + 0.01µ 47µ CTLb Logic 4 Logic 0.1µ IN3 5 C. Video In 0.01µ When superimposition is used GND IN1 C. Video In 1 8 2 7 0.01µ Logic C. Video or DC Out OUT CTLa VCC VCC IN2 3 6 + DC1.7V or more 47µ Logic CTLb 4 Logic 0.1µ IN3 5 DC1.7V or more Fig. 1 • Operation notes (1) To ensure stable clamp operation, the output impedance of the previous stage connected to the inputs should be 1kΩ 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 0.1µF Max. (0.01µF (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 VCC. (4) If control inputs are left open they will be unstable, set to H or L. (5) When using superimposition, the DC voltage directly applied to the inputs should be at least 1.7V. 5 Multimedia ICs BA7653AF •External dimensions (Units: mm) 1 4 0.11 1.27 0.15 ± 0.1 4.4 ± 0.2 5 1.5 ± 0.1 6.2 ± 0.3 5.0 ± 0.2 8 0.4 ± 0.1 0.3Min. 0.15 SOP8 6