7 GEC PLESSEY [SEMICONDUCTORS | SL1611 IS FOR MAINTENANCE PURPOSES ONLY AND IS NOT RECOMMENDED FOR NEW DESIGNS $L1610, SL1611, SL1612 RF/IF AMPLIFIERS The SL1610C, SL1611C and SL1612C are RF voltage amplifiers with AGC facilities. The voltage gains are 10, 20 and 50 times respectively and the upper frequency res- ponse varies from 15 MHz to 120|MHz according to type. wc}1 ~~ aDov Vee (] 2SL1610 7 1 acc SL1611 OUTPUT] 3 1 4642 6 [linpuT aus FEATURES INPUT EARTH] 4 51 input M Wide AGC Range 50dB M Easy Interfacing DP8 MH Integral Power Supply RF Decoupling Fig 1 Pin connections (top view) APPLICATIONS ABSOLUTE MAXIMUM RATINGS Mm RF Ampoiifiers Supply voltage 12V m@ IF Amplifiers Storage temperature 55C tol+1125C ORDERING INFORMATION QUICK REFERENCE DATA $L1610/1/2 C DP M Supply Voitage 6V M Voltage Gain 20dB to 34dB CONDUCTANCE $L1610C SUSCEPTANCE ~ ? i 1 4 SL _ 1611C ri i SL1610C Su SL1612C | 7}4 ADMITTANCE (mmho) o* OUTPUT . Sut | | ai 10 10 100 FREQUENCY (MHz) Fig 2 Block diagram Fig 3 Inout admittance with o/c output {Gq }) 1-137 $L1610/1611/1612 ELECTRICAL CHARACTERISTICS Test conditions (uniess otherwise stated): Supply voltage Vcc 6V Ambient temperature 30C to +85C Test frequency SL1610C 30MHz SL1611C 30MHz SL1612C 1 75MHz Characteristics Circuit ~ Value Units Conditions Min. | Typ. | Max. Supply current $L1610C 15 24 mA SL1611C 15 24 mA No signal, pin 3 open circutt $L1612C 33 6 mA Voltage gain SLi610C } 17 20 24 dB Rs = 500 SL1611C | 23 26 30 dB RL = 500Q SL1612C | 31 34 38 dB Tamo = 22C Cut-off frequency (-3d8) SL1610C 120 MHz SL1611C 80 MHz $L1612C 15 MHz Max.output signal (max AGC) 10 Vrms | RL = 1509 (SL1610C/1611C) RL = 1 2kM (SL1612C) Max.input signal (max AGC) 250 mV rms AGC range SL1610C | 40 50 d8 $L1611C | 40 50 dB Pin 7 OV to 5.1V $L1612C | 60 70 dB AGC current 015; O06 mA | Current into pin 7 at51V APPLICATION NOTES AGC Input circuit The SL1610C, $L1611C and SL1612C are normally used with pins 5 and 6 connected together and with the input connected via a capacitor as shown in Fig 2 The input impedance |s negative between 30MHz and 100MHz (SL1610C, S$L1611C only) and is shown in Fig 3. the source is inductive it should be shunted by a 1kQ resistor to prevent oscillation An alternative input circuit with improved noise figure Is shown in Fig 4 Fig 4 Alternative input circuit Output circuit The output stage ts an emitter follower and has a neg- ative output impedance at certain frequencies as shown In Fig 5 . To prevent oscillation when the load is capacitive a47Q resistor should be connected in series with the output 1-138 When pin 7 !s open circuit or connected to a voltage less than 2V the voltage gain is normal As the AGC voltage !s increased there is a reduction in gain as shown in Fig 6 This reduction varies with temperature 100 161 a0 eo SL1611 RESISTANCE REACTANCE -- 60 40 20 SL1611 S = 0 oO z q -20 z SL1610C = -40 -60 -380 -100 0.1 10 10 FREQUENCY (MHz) Fig 5 Typical output impedance with s/c input (G22) 100 SL1610/1611/1612 Typical applications The circuit of Fig 7 1s ageneral purpose RF preamplifier The voltage gain (from pin 5 to pin 3) is shown in Fig 8 Fig. 9 is the IF section of a simple SSB transceiver At QMHz it has a gain of 100dB i} = oa 1 id o i we o $L1612C S$L1610C SL1611C & = eo RI 7 5h 2 3 47 t]}-+ 5 }--<}-6 outPuT INPUT 3 00ty a 8 gow RELATIVE GAIN (dB) B 0 1.0 2.0 3.0 AGC SIGNAL (V) Fig 6 AGC characteristics (typical) 4.0 5.0 Fig. 7 RF preampiitier INPUT 4 at a 7 QUTPUT ao 3 z +6V = < j=l al S wrt st sy sts SP SAT ost Oi w okt e120 Fitts s6120 ott s| 1612 [= < 0Op e a o > SL1610C Nj 8} 7 i : =47n 09) 11 4) 3 7 =47n 100 4.7n soo) i AGC 0.1 1.0 10 FREQUENCY (MHz) Fig 8 Typical voltage gain (Rs=50Q) 100 Fig. 9 IF ampither using SL1612 1-139