GB4600 Monolithic Unity Gain Video Buffer DATA SHEET FEATURES DESCRIPTION • wideband, unity gain, stable operation (± 0.1 dB at 100 MHz when CL = 27 pF) (full power BW = 120 MHz when CL = 47 pF). The GB4600 is a high performance, monolithic unity gain video buffer made on Gennum's proprietary LSI process. The device features a stable wideband topology capable of driving high capacitance video busses. • selectable high and low current operating modes (I L = 10 mA or I L = 20 mA) • drives high capacitance loads (CL = 180 pF) to 70 MHz at -3 dB. • extremely low differential phase and gain • convenient 8 pin SOIC packaging • 100 mW disabled power consumption FUNCTIONAL BLOCK DIAGRAM INPUT VIDEO SWITCH OUTPUT Optimal system power/bandwidth can be achieved by using the high/low current mode select (I-SET). In addition, the GB4600 can be disabled by taking the ENABLE pin to ground. The ENABLE input is TTL and 5 V CMOS compatible. The GB4600 operates from ± 4.5 to ± 5.5 V power supplies and typically draws 30 mA of current when I -SET is not connected. The supply current drops by approximately 50% when I -SET is directly connected to VEE. A typical application for the GB4600 is interfacing Gennum's wide range of video crosspoint switches. The 8 pin SOIC packaging is ideally suited for space restricted board layouts. APPLICATIONS • Input and output buffering in wide crosspoint matrices • Inter-board video signal buffering ENABLE ENABLE CURRENT SET I-SET • Inter-system video signal buffering AVAILABLE PACKAGING 8 pin SOIC PIN CONNECTIONS ORDERING INFORMATION ENABLE 11 85 GND V EE 22 76 INPUT V CC 33 67 NC OUTPUT 44 58 I-SET Part Number Package Temperature Range GB4600-CKA 8 SOIC 0° to 70°C Revision Date: February 2003 Document No. 13421 - 5 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 VALUE Supply Voltage Operating Temperature Range 0°C to 70°C Storage Temperature Range Analog Input Voltage 260°C -5.5 V £ V IN £ 5.5 V -0.5 V £ VL £ 5.5 V Logic Input Voltage ELECTRICAL CHARACTERISTICS VS = ±5 V, T A = 0° to 70°C, RL = 10kW, CL = 47 pF, R- SET = open circuit unless otherwise shown. PARAMETER Supply Voltage Supply Current DC SUPPLY VS MIN. TYP. MAX. UNITS ±4.5 ±5.0 ±5.5 V I+ - 30 37 mA I- - 30 37 mA I+ R-SET = 0 W - 16 20 mA I- - 16 20 mA Enable = 0 - 0 - mA I - (off) Enable = 0 - 16 50 mA -1.8 - 2.2 V - 12 - mA 5 - 15 mV DVOS - 50 100 mV/°C Chip Enable Time t ON - 100 - ns Chip Disable Time tOFF - 1 - ms Logic Input Thresholds VIH 2.0 - - V VIL - - 0.8 V Analog Output Voltage VOUT Analog Input Bias Current IVBIAS Output Offset Voltage VOS Unclipped Extremes TA = 25°C - I BIAS Enable = 0, TA = 25°C - - 5.0 mA Insertion Loss I.L. ƒ = 100 kHz, TA = 25°C - -0.04 - dB Frequency Response (±0.1dB) F.R. VIN = 1 V p-p CL = 27 pF - 100 - MHz VIN = 1 V p-p, - 120 - MHz Full Power (-3dB) FPBW Input Resistance RIN 1.0 3.0 - MW Input Capacitance CIN - 1.1 - pF Output Resistance ROUT - 2 - W Output Capacitance COUT - 5 - pF Differential Gain dg ƒ = 3.58 MHz - 0.02 - % Differential Phase dp ƒ = 3.58 MHz - 0.02 - deg VIN = 1 V p-p 75 80 - dB - 250 - V/ms Off Isolation at 30 MHz +SR Slew Rate 13421 - 5 CONDITIONS R-SET = 0 W Enable Bias Current DYNAMIC SYMBOL I + (off) Output Offset Voltage Drift LOGIC DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION -65°C to 150°C Lead Temperature (soldering 10 sec.) STATIC CAUTION ELECTROSTATIC SENSITIVE DEVICES ±7.5 V R-SET = 0 (I minimum) VIN = 3 V p-p, CL = 100 pF -SR RS = 12 W - 100 - V/ms +SR VIN = 3 V p-p, CL = 100 pF - 350 - V/ms -SR RS = 12 W - 170 - V/ms 2 +5V TALLY OUT 0.1 GX4201 VIDEO OUT 10K 3 VIDEO INPUT 75 TALLY OUT 1 7 GB4600 4 8 2 5 GX4201 27 TALLY OUT CL *R-SET 0.1 VIDEO OUT -5V VIDEO OUT GX4201 -5V All resistors are in ohms, all capacitors in microfarads unless otherwise stated * The current will be maximum if the pin 5 is left open circuit. Any value of resistance from pin 5 to -VEE will reduce the current. The minimum current (50% of max.) will occur when R-SET = 0 W. TYPICAL APPLICATION CIRCUIT The circuit shown above uses the GB4600 as an input buffer driving several GX4201 video crosspoint ICs. For other applications, the ENABLE input on the GB4600 may be controlled by any TTL or 5 volt CMOS device. The GB4600 is capable of driving loads up to 100 pF to a -3 dB bandwidth of 80 MHz. For lighter loads, the bandwidth is extended to over 100 MHz. A unique feature of the GB4600 is that its current drain can be reduced by adjusting the value of the resistor on the I-SET input, pin 5. Capacitor CL is used to shape the response in conjunction with the 27 W series resistor from pin 4. The value shown will give a -1 dB response at 100 MHz with a total load capacitance (fixed plus actual) of 47 pF. If R-SET is made zero ohms (a direct connection to -VEE) then the supply current drops 50% from 36 mA to 18 mA. A reduced current will reduce the bandwidth as shown in Figure 3. For values of RS = 27 W and CL = 47 pF, the -1 dB bandwidth shrinks from 100 MHz at maximum current to 80 MHz at minimum current. In order to disable the GB4600, pin 1 is driven from the TALLY outputs of the GX4201s. When all crosspoints are OFF, the voltage on pin 1 will be 0 volts, disabling the GB4600. Whenever any crosspoint is selected, the voltage on pin 1 rises to +5 volts and turns on the buffer. This configuration minimizes the current drain when a group of crosspoints are turned off. +5V As with any high frequency circuit, careful board layout with ample ground plane is critical. CHIP ENABLE +5V 0.1 3 VIDEO INPUT 7 75 8 10 K 1 GB4600 4 2 5 RS 4 CL 0.1 -5V 0.1 0.1 RL 10 K 1 COMLINEAR CLC110 8 VIDEO OUT (75 W ) 5 0.1 -5V Max. Min. I-SET -5V All resistors are in ohms, all capacitors in microfarads unless otherwise stated TEST CIRCUIT 3 13421 - 5 TYPICAL PERFORMANCE CURVES FOR THE GB4600 40 1.5 OFF ISOLATION (dB) 1.0 VIN = 1V p-p 50 0.5 GAIN (dB) 70 80 90 100 ISET = MAX. 0 60 1 10 100 -0.5 -1.0 -1.5 -2.0 RS = 27W -2.5 CL = 47pF -3.0 V IN = 1V p-p -3.5 300 I SET = MIN. 10 10 100 Fig. 1 Off - Isolation vs Frequency Fig. 3 1.5 V BLANKING = 0V 0.5 V LUMINENCE = 0.714V 0.04 dg/dp GAIN (d B) 0 -0.5 RS = 18W -1.0 CL = 100pF -1.5 I-SET Bandwidth vs Frequency 0.05 RS = 12W 1.0 200200 FREQUENCY (MHz) FREQUENCY (MHZ) VIN = 40 IRE 0.03 dg 0.02 VIN = 1V p-p -2.0 dp 0.01 -2.5 -3.0 -3.5 1 1 0 100100 10 1 3 Fig. 2 5 10 FREQUENCY (MHz) FREQUENCY (MHz) Fig. 4 Full Power Bandwidth (100 pF) vs Frequency Differential Gain and Phase vs Frequency 75 o AMBIENT TEMPERATURE ( C) 80 (STILL AIR) 70 VS = ±5.0V 65 60 VS = ±5.3V 55 VS = ±5.5V 50 45 40 100 1K 10K 1M R-SET (W) Fig. 5 SOIC Derating Curves DOCUMENT IDENTIFICATION REVISION NOTES: Remove reference to DIP Package. Remove associated part number from DIP package. 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. 13421 - 5 4