( GENNUM 6C4130A Low Distortion EQRAPRPoORrsA TI! OC WW AGC Amplifier DATA SHEET FEATURES CIRCUIT DESCRIPTION The GC4130A contains four functional blocks: * high stability of output level 1. Variable Attenuator * 40 068 AGC operating range 2. Linear Amplitier ; 3. Attenuator Control * d adjustable AGC threshol 4. Voltage Regulator * adjustable release time A vatiable attenuator is placed at the input and is controlled * levels adjustable with external components by a Oc voltage. Withno DC inpul it has an initial attenuation .- ' of 1 io 4 dB; in AGC mode (for input signals larger than the maximum frequency 200 KHz threshold) it maintains a constant ievel at the input of the * operates from standard SV power supply ampalier. The DC voltage at pin 7 is 1.9 V. INTRODUCTION The amplifier has a gain of 33 dB and together with [he attenuator (for input signals lower than ine thrashold}, the gain ig approximately 31 0B, The non-inverting amplifier nag a class AB quiput sage, and the phase shiftof the output signal t is levelindependent. The minimum bandwidih (-3 dB) is 200 kHz. The GOC41304 isa low cost, high performance, easy to use AGC amplifier, in the minimum component configuration id only requires four external capacitors. The output level is maintained constant over 40.08 variation of inpul signal, The SC41304 can drive a B00 & load and can be ooerated vith apower supply valiage of 4.6 to 20 volts. No acdjusinvents are MACRSSAry. The altenuator contol is a window comparator tolowed By a consiant current ouiput stage. The window 1 Set by ihe chip voltage regulator and the comparator responds to both Some potential applications are: negative and positive cycles. The input signal to the intercoms answering machines comparator (pin 4) must be coupked Ihrough an extemal hands-free telephones modems capacitor. The peak-to-peak voltage of [he outpul signal is FA, systems voice operaled devices maintained constant within 0.2 d6 over the AGC operating voice recognition systems infrared security contrals range. To smooch the OC control signal an external titer ultrasonic remote controts capacitor is rquired . An on-chip current source, fogelhar ultrasonic radars & proximity switches with this capacitor, determines therelease time and connecting a resisior in parallel to ihe capacitor will reduce the release time. FUNCTIONAL BLOCK DIAGRAM The voltage regulator powers all the functional blocks except the output stage of the amplifier. The 3.2 V nominalreguiated j= Ce - voltage is rfernced to a lemperature-stable bandgap reference. The regulator voltage is brought out at pin 3 for fitering and external use. PIN. CONNECTIONS NOTE: PiN-OUTS DIFFER SOIC TO POP APLAR Id A oo ATTENUATOR Meet ma C)) ATTENUATOR WA Sh a p> ec cal = ae a THAAD Ta CONTROLLER THAAD oj ps LIT A GND C NA ! Dey AG, ,c Yer t ------- te 3 so oo GND | * 5, ASC 4 40 oura oc, AGo,, GUT A 8 PIN SOIC 8 PIN PDIP Dacument Ma. S10- 82-4 GENANUM CORPORATION P.O, Box 465, Stn 4. Burkington, Ontaro, Canada LA SYS te, (416) 622-2996 fer (416) 6232-2055 tee 061-3525 Japen Branch: 5-201, Miyamae Vilage. 2-10-42 Miyamae, Suginamitu, Toko 168, Japan tel. (0G) 3247-6806 fax (06) 32a7-BAg8 i=)ABSOLUTE MAXIMUM RATING ORDERING INFORMATION Power Supply 20V'0G GC41304EDA | Pin PDIP -40 to + 85C Power Dissipation 300 mi Gcaig0aeKA | arin S0Ic -40 to + a85C Operating Tamperature Range 40 to +8590 ELECTRICAL CHARACTERISTICS Lirttts apoty over-25C aT s 85C Vy=4.5te20. Typical values arealT, =<25C. The test circuit is shown in Figure 6. Parameter | Symbol Conditions / Notes Min. Typ. Max. Linita Supply Voltage Vee 45 3.0 20 VOC Supply Current Toy: ino gignal 2 a 4,7 mA, Reg. Vottage Vireo 3.00 32 35 v Temp. Goat of Vien . 100 prmy*C Kaeo. OVP (Cisne las for Vises: 1 Tw, Decoupling Capacitor Cres for Vises . 47 pF Power Supply Decoupling Capacitor Cy optional - 10 - yr Signal-to-Nolee Aatio at amplifier OF LA - oe My = 100 -1000 mv'p-p at 1 kHz) Total Harmonic Distortion) THD | at ampBlier OP - 0.5 Z Mig = 100-7000 mvp at 7 KHZ, Vig get VWinep ih lop Signal Level Vea - 0.1 4 Ves Output Signal Lawel Veur | in. AGC mode 0.8 0.96. 1.78 VWoHo (Gain A in reat proce - a dae Alten. Input Impedance ran at | wHz & 10 - Wi Oulput impedance four at 1 kHz - 2 Qn Clipping Voltage Veuna BS v Slew Fae = 15 Vilas OVP OG Bias Level AG Sip - 14 VW Source impedance R, for Vy 5 ko Aibenuation Aange at} - dB OVP Gurrent I, Source 3 - rms Sink 3 - mA CHP Voltage Change VP Level Change V,, 20 to 1000 mV nag - o2 510-92 .4100 OUTPUT RELATIVE LEVEL (aB) GAIN 0 Y TLV a ly YY, M/Z Ye 4 i) > 50 4 Oy YU 6 -10 AY Y Yr a 40 Y k/ r 4 SAPO iB 30 y VY A = -20 U7, ) LA 20 30 ZL 400 0 10 107 10 1 10 INPUT SIGNAL (mV AMS) THRESHOLD RESISTANCE (Q) Fig. 2 AGC Characteristics Fig. 3 AGC Threshoid versus Resistance (R,) R z 8 E a 5 Ee 2 a 10 100 1000 100 1.0K 10K 300K 10M 10M INPUT LEVEL (mV RAMS) FREQUENCY (Hz) Fig. 5 Distortion Function of Input Level (AGC Mode) Fig. 4 Amplifier Gain versus Frequency TEST CIRCUIT Voc T The test circuit is shown in Figure 6. The 20 dB Cour out attenuator at the input facilitates measurements at low 8 7 6 | 1 : : : 47 input levels. The input (pin 1) must be capacitively Cw [THR INA Veo OUTA coupled. Any direct coupling of the input will prevent + Cs proper operation. ' GC4130A To = 9.1K oc GNO Va AGC Ts : : IN The output is loaded by a 600 Q resistor through a ine vv 7 2 3 4 2.2 coo capacitor. The resistor is present for test purposes | only. Output loading is not necessary for normal g, K Cr Eva operation. The amplifier output is coupled with the 2.2 Tio attenuator control (AGC,,, pin 4) through a capacitor. Both inputs (IN A and AGC, ) are internally biased and : tr should not be loaded with a DC current. Frequency = response should be measured at input levels lower All resistors in ohms, all capacitors in microfarads unless otherwise stated than the threshold. A value of 8 MV avg (80 MV before the attenuator) is recommended. Fig.6 Test Circuit 510-92-4 J-/3& 1 1b Cw THA 2.2 ee) 2} eno INA CVn yf GC4130A . Vv, R Voc 10 (6.3V) 4Jaccw oural Ail resistors in ohms, all capacitors in microfarads. unless otherwise stated. Fig. 7 Minimum Components Circuit APPLICATIONS Figure 7 shows a minimum component configuration. This should be adequate for most applications. With a 1 pF input Capacitor coupling, the 3 dB cut-off frequency (highpass) is approximately 150 Hz. The AGC filter capacitor, C,, sets the attack and release time. C,, also affects the distortion per- formance at low frequencies. For operation down to 300 Hz, C,, should be a minimum of 2.2 pF. Figure 8 shows a maximum component configuration. An optional capacitor,C,,, has been added for filtering the power supply line. Itis not necessary to have it close to the IC. If there iS a Capacitor already on the supply line, another one is not necessary. The threshold resistor, Ry, is to be used if a higher threshold is desired. The relationship between the threshold voltage and this resistor is shown in Figures 2 and 3. The release time resistor, R,, connected in parallel to C,,, will reduce the release time. The same effect can be obtained by reducing the value of C,.. However , using a resistor ensures a better control of the release time. Finally a potentiometer, R1, and a resistor, R2, are added in order to control the output level, which can only be increased: it Cannot be decreased. The potentiometer can be replaced by two or three resistors in parallel. The output level can be adjusted by cutting one or two of these. In order to avoid clipping, care should be exercised not to exceed 1.5 V p-p output level. 1 OCw THREE 2 G GNO 7 N Sr INA 1 FO IN 7 CV, g] GC4130A 6 + ko Vp Voc 10 4 5 UT g AGCN OUTA {F-o o: Pe $ R, Rt - Coe te 2.5K + 10 R2 5K All resistors in ohms, all capacitors in microfarads uniess otherwise stated. Fig. 8 Maximum Components Circuit AVAILABLE PACKAGING 8 Pin Molded SOIC 8 Pin DIP CAUTION ELECTROSTATIC SENSITIVE DEVICES a 00 NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION REVISION NOTES: -3 Product No. is changed to GC4130A -4 SOIC pin-out added 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 February 1989 Gennum Corporation. Revision Date: December 1991 All rights reserved. Printed in Canada. 510-92-4 5-14