GX214A Monolithic 4x1 Video Multiplexer DATA SHEET FEATURES CIRCUIT DESCRIPTION • low cost The GX214A is a low cost 4x1 video multiplexer containing four analog video switches and a 2 to 4 decoder. A Chip Select input allows paralleled GX214As to be operated in a switching matrix. • differential gain at 3.58 MHz, 0.05% max. • differential phase at 3.58 MHz, 0.05 deg. max. • off-isolation better than 90 dB at 10 MHz • all hostile crosstalk at 3.58 MHz, 75 dB typ. (RIN= 75 Ω) The GX214A represents a fully buffered, unilateral transmission path when enabled. When disabled, the output is high impedance. • make-before-break switching The device operates from ± 7.5 V to ± 9.5 V supplies with TTL and 5 V CMOS compatible input logic levels. FUNCTIONAL BLOCK DIAGRAM IN 0 APPLICATIONS X IN 1 X OUTPUT X IN 2 IN 3 X A0 A1 2 TO 4 DECODER LOGIC • CATV and CCTV systems • low cost video routing Pin 1 14 IN 0 CHIP SELECT CS VCC SIG GND AO IN 1 A1 SIG GND CS IN 2 TRUTH TABLE SIG GND IN 3 CS OUT A1 A0 OUTPUT 0 0 0 IN 0 0 0 1 IN 1 0 1 0 IN 2 0 1 1 IN 3 1 X X HI - Z LOGIC GND 7 8 VEE PIN CONNECTION 14 PIN DIP IN 0 Pin 1 14 AO IN 1 A1 SIG GND CS IN 2 X = DON'T CARE OUT SIG GND IN 3 GX214 - ACDB GX214 - ACKC GX214 - ACKB Package Type 14 Pin DIP 16 Pin SOIC 14 Pin SOIC LOGIC GND 7 VEE 8 PIN CONNECTION 14 PIN SOIC ORDERING INFORMATION Part Number VCC SIG GND Temperature Range 0° to 70°C 0° to 70°C 0° to 70°C IN 0 Pin 1 16 VCC SIG GND NC IN 1 AO SIG GND A1 IN 2 CS SIG GND OUT IN 3 NC LOGIC GND 8 9 VEE PIN CONNECTION 16 PIN SOIC Document No. 520 - 5 - 1 GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946 Japan Branch: A-302 Miyamae Village, 2-10-42 Miyamae, Suginami-ku, Tokyo 168, Japan tel. (03) 3334-7700 fax: (03) 3247-8839 ABSOLUTE MAXIMUM RATINGS Parameter Parameter Value Operating Temperature Range Storage Temperature Range 260 °C Lead Temperature (Soldering, 10 Sec) ± 10.0 V Supply Voltage Value -4 V ≤ V IN ≤ V CC+0.3 V Analog Input Voltage 0 °C ≤ TA ≤ 70 °C 0 V ≤ VL ≤ 5.5 V Logic Input Voltage -65 °C ≤ TS ≤ 150 °C NOTE: A short from output to ground or either supply will destroy the device. For REXT use a 2.67 kΩ 1%, 1/4 W resistor. ELECTRICAL CHARACTERISTICS PARAMETER Supply Voltage VS = ± 8 V DC, 0°C < TA < 70 °C, R L = 2.67 kΩ to V EE , CL = 30pF I L = 3mA SYMBOL SUPPLY Supply Current I- not including I L Analog Output V OUT Voltage Swing STATIC Analog Input Bias MIN TYP MAX 7.5 8.0 9.5 V Chip selected (CS=0) - 14 20 mA Chip not selected (CS=1) - 0.5 0.85 mA Chip selected (CS=0) - 13 18 mA Chip not selected (CS=1) - 0.58 0.88 mA +5.0 V - - -1.2 - 25 - µA +5 -30 -70 mV - 250 400 ns 500 750 - ns ± VS I+ DC CONDITIONS Extremes before clipping occurs I IN UNITS Current Output Offset Voltage V OS 75Ω resistor on each input to ground Turn-On Time t ON Control input to appearance of signal at output. Turn-Off Time t OFF Control input to disappearance of signal at output. LOGIC Logic Input V IH 1 2.4 - - V Thresholds V IL 0 - - 0.6 V Logic Input I BIAS Chip Selected A0,A1 = 1 - - 1 nA Chip Selected A0,A1 = 0 - - 2 µA 1V p-p sine or sq. wave at 100 kHz 0.05 0.08 0.11 dB 65 85 - MHz Bias Current DYNAMIC 520 - 5 - 1 Insertion Loss I.L. Bandwidth (-3dB) B.W. Input Resistance R IN Chip selected (CS = 0) 900 - - kΩ Input Capacitance CIN Chip selected (CS = 0) - 2.0 - pF Chip not selected (CS=1) - 2.2 - pF Output Resistance R OUT Chip selected (CS=0) - 14 - Ω Output Capacitance COUT Chip not selected (CS=1) - 12 - pF Differential Gain dg at 3.58 MHz - - 0.05 % Differential Phase dp V IN = 40 IRE - - 0.05 deg. All Hostile Crosstalk X TALK(AH) Sweep on 3 inputs 1V p-p 4th input has 75 Ω resistor to gnd. ƒ = 10 MHz 72 75 - dB Chip Disabled Crosstalk X TALK(CD) One xpt on output to ground ƒ = 10 MHz 90 100 - dB 2 APPLICATION INFORMATION The circuit layout of any wideband circuit is critical. Good high frequency design practice, proper lead dress and PCB component placement along with a well regulated and decoupled power supply will assure optimum performance of the crosspoint. An external load current of 2 to 8mA should be supplied from each output bus to negative supply. For most applications a load resistor of 2.67kΩ, 1% is recommended to minimize offset drift with temperature. In order to improve differential phase and tighten the insertion loss tolerance, an external constant current active load may be substituted for the load resistor. Note however, that since only one GX214A output drives the output bus at any one time, only one external load is needed for the bus. The GX214A is non-inverting. The inputs are buffered and require 75Ω line terminating resistors when driven from 75Ω cable. The inputs may be driven directly from an amplifier which has low output impedance. A typical application is shown below. Two GX214A ICs are paralleled to form an 8x1 crosspoint matrix. The three address lines make use of the A0, A1 and CS inputs. If more than two devices are used in parallel, a decoder is necessary in order to generate the extra address inputs. The output of the GX214A must be buffered to drive 7 Ω lines. The addition of an amplifier/buffer also allows adjustments to be made to the gain, offset and frequency response of the circuit. Signal Ground (SG) pins 2, 4 and 6 must be joined together and preferably form part of a ground plane. The Signal Ground must also be connected to the ± 8V power supply ground. The potential of the Logic Ground (LG) pin 9 can deviate from the Signal Ground by ±0.5V maximum. Alternatively, the signal and logic grounds can be joined together at one point only. INPUTS VIDEO SWITCHES +8V 0.1 1 V0 V1 SG 3 5 V2 6 7 V3 75 75 IN 0 2 4 75 Depending on the application and the speed of the logic family used, latches may be required for synchronization where timing delays are critical. The active switching circuitry of the GX214A ensures low crosstalk and high performance over an input voltage range of -1.2 to +5.0 volts. +V 14 13 A0 IN 1 A0 12 A1 SG CS 11 A2 IN 2 OUT SG LG -V IN 3 A 1 ADDRESS 10 9 8 0.1 75 -8V +8V 0.1 1 IN 0 V4 V5 2 SG 3 IN 1 4 SG 5 V6 6 7 V7 75 75 75 75 IN 2 SG IN 3 14 +V 13 A0 A 1 12 11 CS 10 OUT 9 LG 8 -V GAIN, OFFSET, FREQUENCY RESPONSE ADJUSTMENTS V OUT 75 2.67 K AMPLIFIER/BUFFER 0.1 All resistors in ohms, all capacitors in microfarads, unless otherwise stated -8V Fig. 1 8x1 Video Multiplexer Incorporating Two GX214A Devices 3 520 - 5 - 1 5 0.0 4 -0.5 3 -1.0 2 -1.5 PHASE (deg) GAIN (dB) TYPICAL PERFORMANCE CURVES FOR GX214A VS = ± 8V, CL = 30pF, IL = 3mA unless otherwise shown 1 0 -1 -2.0 -2.5 -3.0 -2 -3.5 -3 -4.0 -4 -4.5 -5 1 1 -5.0 1 1 100 100 10 3 FREQUENCY (MHz) -20 0.05 -30 0.04 -40 0.03 dg(%) dp( o) GAIN (dB) XTALK (AH) RS=75Ω -60 -70 -80 IN 1,2 OFF ISOLATION RL=15Ω IN 0,3 -90 10 10 Fig. 3 Phase vs Frequency Fig. 2 Gain vs Frequency -50 5 FREQUENCY (MHz) V =40 IRE IN 0.02 0.01 dg 0.00 -0.01 -0.02 -100 -0.03 -110 -0.04 dp -120 1 10 -0.05 100 11 3 FREQUENCY (MHz) 5 Fig. 4 All - Hostile Crosstalk & Off-Isolation vs Frequency Fig. 5 Differential Gain & Phasevs Frequency +5V FROM NETWORK ANALYSER 1 2 75 IN0 AG A0 A1 CS OUT LG 13 0.1 12 1 11 4 CLC110 10 9 14 8 -8V +8V 8 5 2.67k VCC VEE TO NETWORK ANALYSER 0.1 -5V * * * The power supply pins should be suitably decoupled with at least 0.1µF, high quality capacitors All resistors in ohms, all capacitors in microfarads unless otherwise stated. Fig. 6 Test Circuit The TEST SET UP shown is for INPUT 0 tests. Similar circuitry is used for each input INPUT in order to test FREQUENCY RESPONSE and PHASE DELAY. For OFF-ISOLATION, all switches are disabled (CHIP SELECT = logic 1) and a second enabled GX214A is connected to the output bus. For ALL-HOSTILE CROSSTALK, three OFF switches are driven from the generator and the fourth is terminated with a 75Ω resistor. For the DIFFERENTIAL GAIN and PHASE tests, the output is AC coupled to the output amplifier and the input level from the generator is modulated with a step signal varying between 0 volts DC and 0.714 volts DC. 520 - 5 - 1 10 10 FREQUENCY (MHz) 4 CAUTION ELECTROSTATIC SENSITIVE DEVICES DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION 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 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. REVISION NOTES . 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. Block diagram added,new test circuit, revised electrical characteristics, new application circuit, all new response graphs. 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 July 1990 Gennum Corporation. Revision Date: February 1993. All rights reserved. 5 Printed in Canada. 520 - 5 - 1