GX214A GENNUM

Document overview

  • Manufacturer or author: Provided By digicamel.com
  • PDF pages: 5

Technical content

V EE 8 7 14Pin 1 IN 0 SIG GND IN 1 SIG GND IN 2 SIG GND IN 3 VCC AO CS OUT LOGIC GND V EE 8 7 14Pin 1 FUNCTIONAL BLOCK DIAGRAM GX214A Monolithic 4x1 Video Multiplexer 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 Document No. 520 - 5 - 1 CS 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

X = DON'T CARE TRUTH TABLE

ORDERING INFORMATION

14 PIN DIP

X X X X

2 TO 4 DECODER

14 PIN SOIC

V EE 8 9 16Pin 1 PIN CONNECTION

16 PIN SOIC

Part Number Package Type Temperature Range GX214 - ACDB 14 Pin DIP 0 ° to 70°C GX214 - ACKC 16 Pin SOIC 0 ° to 70°C GX214 - ACKB 14 Pin SOIC 0 ° to 70°C

FEATURES

  • low cost
  • 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 )
  • make-before-break switching CIRCUIT DESCRIPTION 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. The GX214A represents a fully buffered, unilateral transmission path when enabled. When disabled, the output is high impedance. The device operates from ± 7.5 V to ± 9.5 V supplies with TTL and 5 V CMOS compatible input logic levels.

APPLICATIONS

  • CATV and CCTV systems
  • low cost video routing DATA SHEET

Supply Voltage ± VS 7.5 8.0 9.5 V DC I+ Chip selected (CS=0) - 14 20 mA SUPPLY Chip not selected (CS=1) - 0.5 0.85 mA I- Chip selected (CS=0) - 13 18 mA Chip not selected (CS=1) - 0.58 0.88 mA Analog Output V OUT Extremes before +5.0 V Voltage Swing clipping occurs - - -1.2 STATIC Analog Input Bias IIN -2 5- µ A Current Output Offset Voltage V OS 75Ω resistor on each +5 -30 -70 mV input to ground Turn-On Time t ON Control input to appearance - 250 400 ns of signal at output. Turn-Off Time t OFF Control input to disappear- 500 750 - ns ance of signal at output. LOGIC Logic Input V IH 1 2.4 - - V Thresholds V IL 0 - - 0.6 V Logic Input IBIAS Chip Selected A0,A1 = 1 - - 1 nA Bias Current Chip Selected A0,A1 = 0 - - 2 µ A at 100 kHz Bandwidth (-3dB) B.W. 65 85 - MHz Input Resistance R IN Chip selected (CS = 0) 900 - - k Ω DYNAMIC Input Capacitance C IN 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 C OUT 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. Sweep on 3 inputs 1V p-p All Hostile Crosstalk X TALK(AH) 4th input has 75 Ω resistor 72 75 - dB to gnd. ƒ = 10 MHz Chip Disabled Crosstalk X TALK(CD) One xpt on output to ground 90 100 - dB ƒ = 10 MHz Parameter Value Supply Voltage ± 10.0 V Operating Temperature Range 0 °C ≤ TA ≤ 70 °C Storage Temperature Range -65 °C ≤ TS ≤ 150 °C PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current not including IL ABSOLUTE MAXIMUM RATINGS Parameter Value Lead Temperature (Soldering, 10 Sec) 260 °C Analog Input Voltage -4 V ≤ VIN ≤ VCC+0.3 V Logic Input Voltage 0 V ≤ VL ≤ 5.5 V 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 VS = ± 8 V DC, 0°C < TA < 70 °C, RL = 2.67 k Ω to V EE, CL = 30pF IL = 3mA

0.1 V 4 V 5 V 6 V 7 75 75 75 75 0.1 0.1 0.1 -8V -8V +8V +8V A 0 A 1 A 2 IN 0 SG IN 1 SG IN 2 SG IN 3 A 0 A 1 CS OUT LG IN 0 SG IN 1 SG IN 2 SG IN 3 A 0 A 1 CS OUT LG ADDRESS GAIN, OFFSET, FREQUENCY RESPONSE ADJUSTMENTS AMPLIFIER/BUFFER V OUT 2.67 K 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 2.67k Ω , 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. 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. 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 per- formance over an input voltage range of -1.2 to +5.0 volts. Fig. 1 8x1 Video Multiplexer Incorporating Two GX214A Devices

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. The GX214A is non-inverting. The inputs are buffered and require 75 Ω line terminating resistors when driven from 75 Ω cable. The inputs may be driven directly from an amplifier which has low output impedance. 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. All resistors in ohms, all capacitors in microfarads, unless otherwise stated

Fig. 2 Gain vs Frequency Fig. 4 All - Hostile Crosstalk & Off-Isolation vs Frequency 1 10 100 GAIN (dB) 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 PHASE (deg) 1 3 5 10 Fig. 3 Phase vs Frequency FREQUENCY (MHz) FREQUENCY (MHz) * * 1 10 dg(%) dp(o) 0.05 0.04 0.03 0.02 0.01 0.00 -0.01 -0.02 -0.03 -0.04 -0.05 FREQUENCY (MHz) Fig. 5 Differential Gain & Phasevs Frequency dg dp VIN=40 IRE 1 3 5 10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 GAIN (dB)IN 1,2 XTALK (AH) RS=75Ω OFF ISOLATION RL=15ΩIN 0,3 1 10 100 FREQUENCY (MHz) TYPICAL PERFORMANCE CURVES FOR GX214A VS = ± 8V, CL = 30pF, IL = 3mA unless otherwise shown 1075 +5V 0.1 0.1 TO NETWORK ANALYSER CLC110 2.67k FROM NETWORK ANALYSER 1 13 -8V+8V IN0 AG CS OUT LG VCC VEE -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 75 Ω 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.

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. Printed in Canada. 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. 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. CAUTION ELECTROSTATIC SENSITIVE DEVICES DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION REVISION NOTES . Block diagram added,new test circuit, revised electrical characteristics, new application circuit, all new response graphs.