GT4123B Two Channel Video Multiplier DATA SHEET FEATURES DESCRIPTION two-quadrant video multiplication The GT4123B is a monolithic dual-channel video multiplier for use in a wide range of applications including broadcast and multimedia. operation from ±4.5 V to ±13.2 V supply voltages 20 MHz ±0.1 dB video & control channel bandwidth ultra low differential gain & differential phase Featuring two wideband video inputs and a single control input, the GT4123B achieves broadcast quality mixing of two video input signals to a single output by implementing the function: convenient 8 pin package VO = [ ( VC • VA) + (1 - VC) • VB ] Pb-free and Green where VC is the control input voltage, which may be varied continuously over the range 0 V to 1 V, and VA and V B are the video input signals. APPLICATIONS The GT4123B is a low power version of the GT4123 and GT4123A Video Multipliers which operates from ±5 V supply voltages and typically draws only 15 mA of current. • Multimedia Graphics Overlay • Production Switchers • Linear Keyers PIN CONNECTIONS FUNCTIONAL BLOCK DIAGRAM GT4123B FREQ COMP VIDEO IN A OUTPUT 1 8 V FREQ. COMP 2 7 VIDEO IN B CONTROL 3 6 V GROUND 4 5 VIDEO IN A cc MULTIPLIER CORE VIDEO IN B OUTPUT EE CONTROL VREF (0.5V) (INTERNAL) ORDERING INFORMATION Part Number Package Type Temperature Range Pb-Free and Green GT4123BCDA 8 pin PDIP 0° to 70° C No GT4123BCKA 8 pin SOIC 0° to 70° C No GT4123BCTA 8 pin SOIC Tape 0° to 70° C No GT4123BCKAE3 8 pin SOIC 0° to 70° C Yes Revision date: July 2004 Document No. 521 - 20 - 02 GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946 Gennum Japan: Shinjuku Green Tower Building 27F 6-14-1, Nishi Shinjuku Shinjuku-ku, Tokyo 160-0023 Japan Tel: +81 (03) 3349-5501 Fax: +81 (03) 3349-5505 ABSOLUTE MAXIMUM RATINGS PARAMETER CAUTION VALUE/UNITS Supply Voltage ELECTROSTATIC SENSITIVE DEVICES ±13.5 V 0°C ≤ TA ≤ 70°C Operating Temperature Range DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION -65°C ≤ TS ≤150°C Lead Temperature (soldering, 10 seconds) 260°C Storage Temperature Range Video Input Voltage ±5 V Control Input Voltage ±5 V Video Input Differential Voltage ±5 V ELECTRICAL CHARACTERISTICS GT4123B PARAMETER POWER SUPPLIES VS = ±5V, T A = 0°C to 70°C, RL=10kΩ, C L=10pF unless otherwise shown. SYMBOL CONDITIONS MIN TYP MAX UNITS ±4.5 ±5 ±13.2 V Supply Voltage ±VS + Supply Current I+ - 15 19.5 mA - Supply Current I- - 15 19.5 mA Common Mode Input Signal V IN CM - - 2.2 V Supply Voltage = ±5 V Positve Excursion Limit Negative Excursion Limit Bandwidth - - -3.5 V 10 - - MHz 20 25 - MHz - 0.01 0.02 % - 0.01 0.03 deg 60 70 - dB -0.02 -0.005 - dB - 4 10 ns ƒ = 1 kHz 70 - - dB ƒ = 10 MHz 25 - - dB V A or B/V O ƒSIG = 5 MHz (see note 1) 70 75 - dB V C/VA or B ƒSIG = 5 MHz (see note 2) 80 85 - dB BW0.05 BW 0.1 Differential Gain dg Differential Phase dp ±0.05 dB, V IN= 150 mVp-p ±0.1 dB, VIN= 150 mVp-p V IN = 40 IRE, 0V CM at 3.58 MHz and 4.43 MHz V IN = 40 IRE, 0V CM at 3.58 MHz and 4.43 MHz SIGNAL PATH PP Signal / RMS Noise S/N V SIG = 1 Vp-p, Gain AV 100 kHz (ß = 100%) Delay td SIG PSRR Power Supply Rejection Ratio Off Isolation & Crosstalk CONTROL CHANNEL Output Offset Channel A or Channel B - - ±15 mV Offset Difference Channel A - Channel B 0 - ±5 mV Input Resistance RIN Input Capacitance CIN Output Resistance ROUT Output Capacitance COUT Bandwidth BW0.1 Delay tD CONT ƒ=1 MHz at ±0.1 dB, VIN = 150 mVp-p Linearity Control Breakthrough VC = 0 to 1 V ƒ C =1 to 10 MHz V C = 0 to 1 V ƒ C = 3.58 MHz Crossfade Balance Control Range NOTE: ƒ=1 MHz VC 1. V A or B = +1 Vp-p, output taken from OUTPUT 2 . V C = +1 Vp-p, output taken from VA or VB 521 - 20 - 02 2 of 5 100 - - kΩ - 2.0 - pF - - 0.50 Ω - 2.0 - pF 15 20 - MHz - 4 10 ns - - 1.5 % - - -35 dB -15 0 +15 mV 0 - +1 V DETAILED DESCRIPTION The GT4123B is a low power two quadrant video multiplier for use in a wide range of applications including broadcast and multimedia. When VC is less than 0.5 V, VCA reduces and VCB increases in proportion so that less of Channel A and more of Channel B signal is transferred. Similarly, when VC is greater than 0.5 V, the opposite occurs. The internal topology of the device is shown in Figure 1 below. The SPAN or control range is internally set so that a CONTROL voltage of 0 V completely cuts off Channel A and fully turns on Channel B. Similarly, a CONTROL voltage of 1 V will fully turn on Channel A and completely turn off Channel B. IN A AMP A COMP XA + VCA + Σ1 + AMP D OUT IN B AMP B XB + VCB = 0.5 - (VC - 0.5) + CONTROL (VC) AMP C + VCB VCA = 0.5 + (VC - 0.5) Σ2 + + Σ3 + The linear portion of the transfer characteristic has a linearity of better than 1.5%. The outputs from the multipliers are applied to an analog summing circuit (å1) whose output feeds a wideband amplifier (Amp D) and presents the mixed signals to the outside world. The inverting nodes of each input are directly connected to the output. 0.5V REF Fig. 1 There is a small dead band at either end of the CONTROL input. The amount of dead band is about 100 mV. The CONTROL input can be preceded by an operational amplifier to overcome the dead band and level shift the control signal so that other than 0 to 1 V range can be used. The bandwidth of the CONTROL input is in the order of 20 MHz at ±0.1 dB to allow for very fast KEY signals. Functional Block Diagram of the GT4123B Each input is applied to a differential amplifier (AMP A and AMP B). From the amplifiers, the signals are passed 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, the GT4123B lends itself to high density, multi-function PC board layouts in devices such as RGB mixers and four layer keyers where close control law tracking is essential. The internal control voltages are derived from a unity gain differential amplifier (AMP C) whose outputs (true and invert) are the difference between an internal 0.5 V reference voltage, and the externally applied CONTROL voltage. In addition, the internal DC offset of 0.5 V is applied to the controlling voltage summing circuits å2 and å3. Therefore, VCA = 0.5 V + (VC - 0.5 V) and VCB = 0.5 V - (VC - 0.5 V) When the control input VC equals 0.5 volts, VCA = 0.5 V and VCB = 0.5 V, and 50% of each input signal passes to the output of the multiplier stages. 3 of 5 521- 20 - 02 +5V 0.1 8 7 +5V 5 - 30pF 4 2 150 FROM NETWORK ANALYSER 75 0.1 GT4123B 5 4 CLC110 1 3 6 1 0.1 TO NETWORK ANALYSER 8 5 75 10k 0.1 -5V B 0.1 A -5V All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 2 +1V Frequency Response, Cross Talk, Differential Gain & Phase Test Circuit +5V -5V 0.1 0.1 8 6 6dB AMPLIFIER VIDEO OUT GT4123B VA 5 1 75 7 75 4 3 2 VB 150 75 5-30 pF VC All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 3 (VS = ±5V, unless otherwise specified) 0.2 0 0.1 -20 0 -40 CROSSTALK (dB) GAIN (dB) GT4123B TYPICAL PERFORMANCE CURVES Typical Application Circuit -0.1 VS = ±12V -0.2 VS = ±5V -80 VC - CHANNEL A -100 -0.3 -120 -0.4 0.1 1 10 1 100 10 100 FREQUENCY (MHz) FREQUENCY (MHz) Fig. 4 Frequency Response 521 - 20 - 02 VC - CHANNEL B -60 Fig. 5 Crosstalk vs Frequency 4 of 5 2.5 0.03 OUTPUT RESISTANCE (ý) 0.02 dg / dp 0.01 0 dg dp -0.01 -0.02 2 1.5 1 0.5 0 -0.03 1 10 0.1 FREQUENCY (MHz) 1 10 FREQUENCY (MHz) Fig. 6 dg & dp vs Frequency CH-B Fig. 7 Output Resistance vs Frequency CH-A GAIN (%) 100 50 0 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 CONTROL VOLTAGE (VC) Fig. 8 Control Characteristics 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 September 1994 Gennum Corporation. All rights reserved. Printed in Canada. 5 of 5 521- 20 - 02