GT4123, GT4123A Two Channel Video Multipliers DATA SHEET FEATURES DESCRIPTION • two-quadrant video multiplication • 20 MHz 0.1 dB video & control channel bandwidth • one external frequency compensation adjustment • ultra low differential gain & differential phase The GT4123 and GT4123A are monolithic dual-channel video multipliers for use in a wide range of applications including broadcast and multimedia. Featuring two wideband video inputs and a single control input, they achieve high quality video mixing of the two video input signals to a single output by implementing the function: • convenient 8 pin package VO = [ ( VC • VA ) + (1 - VC ) • VB ] where VC is the control input voltage, which may be varied continuously over the range 0 to 1V with respect to the ground pin, and VA and V B are the video input signals. APPLICATIONS • Multimedia Graphics Overlay • Production switchers The GT4123 operates with typical power supply voltages of ± 10 volts and draws 15 mA of current. The GT4123A typically operates from +12 and -5 volt supplies. Both are available in 8 pin PDIP and 8 pin SOIC. • Linear Keyers PIN CONNECTIONS An Application Note entitled "Using the GT4123 and GT4123A Video MIxer ICs" (Document No. 520 - 61) is available from Gennum Corporation. TOP VIEW OUTPUT PIN 1 8 FREQ. COMP cc VIDEO IN B V EE CONTROL GROUND V 4 5 FREQ COMP VIDEO IN A VIDEO IN A MULTIPLIER CORE 8 PIN DIP VIDEO IN B ORDERING INFORMATION Part Number Package Type GT4123 - CDA GT4123 - CKA GT4123ACDA GT4123ACKA 8 pin PDIP 8 pin SOIC 8 pin PDIP 8 pin SOIC OUTPUT CONTROL Temperature Range 0o 0o 0o 0o to 70o C to 70o C to 70o C to 70o C VREF (0.5V) (INTERNAL) FUNCTIONAL BLOCK DIAGRAM CAUTION ELECTROSTATIC SENSITIVE DEVICES DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION Revision Date: January 1994. GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 Japan Branch: A-302, M i yamae Vi l l age, 2–10–42 M i yamae, Suginami–ku Tokyo 168, Japan Document No. 520 - 38 - 3 tel. (905) 632-2996 fax: (905) 632-5946 tel. (03) 3334-7700 fax (03) 3247-8839 ABSOLUTE MAXIMUM RATINGS PARAMETER VALUE Supply Voltage (VS) ± 13.5 V 0° C ≤ TA ≤ 70° C Operating Temperature Range Storage Temperature Range -65° C ≤ TS ≤ 150° C Lead Temperature (Soldering, 10 Sec) 260° C Video Input Voltage (VA,VB) to ground ±5 V Control Input Voltage (VC) to ground ±5 V Video Input Differential Voltage (VA - VB) ±5 V ELECTRICAL CHARACTERISTICS GT4123 PARAMETER POWER SUPPLIES V S = ±10V, T A = 0°C to 70°C, RL =10kΩ unless otherwise shown. SYMBOL UNITS ±9 ± 10 ± 12 V I+ - 15 19.5 mA - Supply Current I- - 13 17.0 mA Common Mode Input Signal VIN CM Bandwidth BW0.1 Bandwidth BW3 - - 5 V 20 25 - MHz - 80 - MHz DC -10 MHz - ± 0.05 - dB at ± 0.1 dB VIN = 150 mVp-p at -3 dB VIN = 1 Vp-p Differential Gain ∂g VIN = 40 IRE at 3.58 MHz - 0.01 0.05 % Differential Phase ∂p VIN = 40 IRE at 3.58 MHz - 0.01 0.05 degrees Signal to Noise S/N VSIG = 1 V, BW = 5 MHz 64 70 - dB Gain AVL 100 kHz (ß = 100%) -0.02 -0.005 - dB Delay td SIG VA or B VO VC VA or B - 4 10 ns ƒSIG = 5 MHz (see note 1) 70 75 - dB ƒSIG = 5 MHz (see note 2) 80 85 - dB RIN ƒ=1 MHz 150 - - kΩ - 2.0 - pF - - 0.1 Ω - 2.0 - pF 20 25 - MHz Input Capacitance CIN Output Resistance ROUT Output Capacitance COUT Bandwidth BW0.1 Bandwidth BW3 Delay tD CONT ƒ=1 MHz (see Figure 9) at ± 0.1 dB VIN = 150 mVp-p at -3 dB VIN = 1 Vp-p - 80 - MHz - 4 10 ns Linearity 10% to 90% range - 1 - % Control Breakthrough VC = 0 to 1 V ƒ C =1 to 10 MHz VC = 0 to 1 V ƒ C = 3.58 MHz - - -35 dB - 5 10 mVp-p (see Figure 10) 0 - +1 V Crossfade Balance Control Range VC 1. V A or B = +1 Vp-p output taken from OUTPUT 2 . VC = +1 Vp-p output taken from VA or V B 520 - 38 - 3 MAX + Supply Current Input Resistance NOTE: TYP VS Off Isolation & Crosstalk CONTROL CHANNEL Operating Range MIN Supply Voltage Frequency Response SIGNAL CHANNEL CONDITIONS 2 ELECTRICAL CHARACTERISTICS GT4123A PARAMETER Supply Voltage POWER SUPPLIES V S = ±12V, -5V, TA = 0°C to 70°C, RL=10kΩ unless otherwise shown. SYMBOL VS CONTROL CHANNEL TYP MAX UNITS +9 +12 ± 12 V -3 -5 I+ - 15 19.5 mA - Supply Current I- - 13 17.0 mA Common Mode Input Signal VIN CM - - 5 V Bandwidth BW 0.1 20 25 - MHz Bandwidth BW 3 at ± 0.1 dB V IN = 150 mVp-p at -3 dB V IN = 1 Vp-p - 80 - MHz DC -10 MHz - ± 0.05 - dB Differential Gain ∂g VIN = 40 IRE at 3.58 MHz - 0.02 0.05 % Differential Phase ∂p VIN = 40 IRE at 3.58 MHz - 0.02 0.05 degrees Signal to Noise S/N VSIG = 1 V, BW = 5 MHz Gain AVL 100 kHz (ß = 100%) Delay Off Isolation & Crosstalk t d SIG VA or B VO VC VA or B ƒ SIG = 5 MHz (see note 1) Input Resistance RIN ƒ=1MHz Input Capacitance CIN Output Resistance ROUT Output Capacitance COUT Bandwidth BW 0.1 Bandwidth BW 3 Delay t D CONT ƒ SIG = 5 MHz (see note 2) ƒ=1MHz (see Figure 9) at ± 0.1 dB V IN = 150 mVp-p at -3 dB V IN = 1 Vp-p 64 70 - dB -0.02 -0.005 - dB - 4 10 ns 70 75 - dB 80 85 - dB 150 - - kΩ - 2.0 - pF - - 0.1 Ω - 2.0 - pF 20 25 - MHz - 80 - MHz - 4 10 ns Linearity 10% to 90% range - 1 - % Control Breakthrough V C = 0 to 1 V ƒC =1 to 10 MHz - - -35 dB Crossfade Balance VC = 0 to 1 V ƒ C = 3.58 MHz - 5 10 mVp-p (see Figure 10) 0 - +1 V Control Range NOTE: Operating Range MIN + Supply Current Frequency Response SIGNAL CHANNEL CONDITIONS VC 1. V A or B = +1 Vp-p output taken from OUTPUT 2 . VC = + 1 Vp-p output taken from V A or V B 3 520 - 38 - 3 DETAILED DESCRIPTION When VC is less than 0.5 volts, VCA reduces and VCB increases in proportion so that less of the Channel A signal and more of the Channel B signal is transferred. Similarly, when VC is greater than 0.5 volts, the opposite occurs. The GT4123 and GT4123A are the first dedicated single device, two input video mixer ICs available to the professional video and multimedia markets. The internal topology of the devices is shown in Figure 1. The SPAN or control range is internally set so that a CONTROL voltage of 0 volts completely cuts off Channel A and fully turns on Channel B. Similarly, a CONTROL voltage of 1 volt will fully turn on Channel A and completely turn Channel B off. AMP A IN A XA COMP Figure 10 shows the CONTROL transfer characteristics of the GT4123 and GT4123A. OUT There is a small ‘dead band’ at either extreme of the CONTROL input. The amount of ‘dead band’ is about 100 mV and is shown in Figure 10. The CONTROL input can be preceded by an operational amplifier so biased as to overcome this ‘dead band’ as well as level shift the control signal so that other than 0 to 1 volt ranges can be used. The bandwidth of the CONTROL input is sufficient to allow very fast keying and is in the order of 20 MHz at -0.1 dB. + + VCA Σ1 + AMP D IN B AMP B XB + VCB = 0.5 - (VC - 0.5) + CONTROL (VC) AMP C + VCB VCA = 0.5 + (VC - 0.5) Σ2 + + Σ3 + 0.5V The linear portion of the transfer characteristic has a linearity of 1% or better. REF Fig. 1 The outputs from the multipliers are applied to an analog summing circuit (Σ1) whose output feeds a wideband amplifier (Amp D) and presents the mixed signals to the outside world. The inverting inputs of each input amplifier are directly connected to the output. Functional Block Diagram of the GT4123 and GT4123A Each input signal is applied to a conventional differential amplifier (AMP A and AMP B). From the amplifiers, the signals are applied to analog multiplier circuits (XA and XB) whose outputs are the product of the input signals and internally generated controlling voltages VCA and VCB. In this manner the closed loop gain is nearly unity providing wideband, stable operation. Because the devices have only 8 pins and require virtually no external parts in order to function, they lend themselves to high density, multi-functional PC board layouts. Several devices can be used in parallel applications such as R-G-B mixers and four-layer keyers where close control law tracking is essential. These voltages are derived from a unity gain differential amplifier (AMP C) whose outputs (true and invert) are the difference between an externally applied CONTROL voltage (VC) and an internal 0.5 volt reference voltage. In addition, the internal DC offset of 0.5 volts is applied to the controlling voltage summing circuits Σ2 and Σ3. The only difference between the GT4123 and the GT4123A is the fact that the latter device can operate with non-equal power supplies. The negative supply can be as low as -3 volts unlike the GT4123 which can only operate down to ± 9 volt supplies. Therefore, VCA = 0.5V + (VC - 0.5V) and VCB = 0.5V - (VC - 0.5V) When the CONTROL input (VC ) equals 0.5 volts, V CA and VCB = 0.5 volts and exactly 50% of each input signal passes to the output of the multiplier stages. 520 - 38 - 3 4 GT4123 / GT4123A TEST CIRCUITS +10V 0.1 +5V 7 8 0.1 4 1 75 DUT 4 CLC110 1 0.1 5 5 10k 3 6 TO NETWORK ANALYSER 8 0.1 75 -5V 0.1 -10V FROM NETWORK ANALYSER All resistors in ohms, all capacitors in µF unlesss otherwise stated. VSIG = 1VP-P + 0.5V BIAS (100 kHz to 10 MHz) Fig. 2 Crossfade Balance +10V 0.1 7 FROM NETWORK ANALYSER 8 4 +5V 5 - 30pF 2 680 75 0.1 DUT 5 6 1 3 4 CLC110 1 0.1 8 5 75 TO NETWORK ANALYSER 10k 0.1 -5V B 0.1 A -10V All resistors in ohms, all capacitors in µF unlesss otherwise stated. +1V Fig. 3 Frequency Response, Crosstalk & Differential Gain & Phase (+12V) +10V (-5V) -10V 0.1 0.1 8 6 6dB AMPLIFIER GT4123 (GT4123A) VA 5 75 VIDEO OUT 1 75 7 4 3 2 All resistors in ohms, all capacitors in µF unlesss otherwise stated. VB 680 75 5-30 pF VC Fig. 4 Typical Application Circuit 5 520 - 38 - 3 TYPICAL PERFORMANCE CURVES FOR GT4123 / GT4123A 0.5 -20 0.4 -30 CH-A VIN=1Vp-p 0.3 -40 0.2 -50 0.1 CH-A 0.0 dB dB CH-B -0.1 -60 -70 -0.2 CH-B VIN = 150mVp-p -0.3 RCOMP = 680Ω -0.4 CCOMP = 18pF -80 -90 -0.5 1 1 -100 1 1 100 10 100 Fig. 5 100 Fig. 6 Crosstalk vs Frequency Frequency Response 0.03 -30 0.02 -35 VC = 1Vp-p+0.5VDC 0.01 REF = 1Vp-p (0dB) -40 dg 0.00 dB dg / dp 100 10 FREQUENCY (MHz) FREQUENCY (MHz) -0.01 -45 -50 dp -0.02 -55 -0.03 1 1 3 -60 10 5 0.1 10 1 10 FREQUENCY (MHz) FREQUENCY (MHz) Fig. 7 Differential Gain & Phase vs Frequency Fig. 8 Crossfade Balance vs Frequency 1.0 CH-A CH-B 0.9 100 0.8 GAIN (%) RESISTANCE (Ω) 0.7 0.6 0.5 0.4 50 0.3 0.2 0 0.1 0.0 01 0.01 0.1 1.0 10 10 -0.2 FREQUENCY (MHz) 0.2 0.4 0.6 0.8 CONTROL VOLTAGE (VC ) Fig. 10 Control Characteristics Fig. 9 Output Resistance vs Frequency 520 - 38 - 3 0.0 6 1.0 1.2 Revision Notes: Detailed Description added. DOCUMENT IDENTIFICATION PRODUCT PROPOSAL This data has been compiled for market investigation purposes only, and does not constitute an offer for sale. ADVANCE INFORMATION NOTE This product is in a development phase and specifications are subject to change without notice. Gennum reserves the right to remove the product at any time. Listing the product does not constitute an offer for sale. PRELIMINARY DATA SHEET The product is in a preproduction phase and specifications are subject to change without notice. DATA SHEET The product is in production. Gennum reserves the right to make changes at any time to improve reliability, function or design, in order to provide the best product possible. Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. © Copyright May 1991 Gennum Corporation. All rights reserved. Printed in Canada. 7 520 - 38 - 3