MOTOROLA SEMICONDUCTOR SaaS TECHNICAL DATA Low-Level Video Detector Rananan Tne MCi330A is an iniegraied circuit featuring very linear video characteristics and wide bandwidth. Designed for color and monochrome television receivers, replacing the third IF, detector, video buffer and AFC buffer. Conversion Gain: 33 dB (Typ) Fully Balanced Detector MAXIMUM RATINGS Excellent Differential Phase and Gain High Rejection of IF Carrier Feedthrough High Video Output: 8.0 V(p-p) Output Temperature Compensated Improved Version of the MC1330 MC1330A LOW-LEVEL VIDEO DETECTOR SILICON MONOLITHIC INTEGRATED CIRCUIT Rating Value Unit Power Supply Voitage 24 Vde DC Video Output Current 5.0 mAdc DC AFT Output Current 2.0 P SUFFIX PLASTIC PACKAGE Junction Temperature 150 C CASE 626 Operating Ambient Temperature Range Oto 75 C Storage Temperature Range -65 to +150 C Figure 1. Circuit Schematic Ri 48k 30 Tuned Gircuit 22 6 Vee . RQ : RIO : R7 ra 6.95 6.4k Q20 Ri Q25 2.2k 2.2k k 4,35k Ny Q24 1 R2 Kar9 --O AFT 3.6k Bufter LL D1 2 Output at wt 14boy Q9 Q10 oc Hl O15 16 D2 L_ pag AUX IF 5 video utput meg | % me Oe OR aL on 5K i Kee 3k o7 ais Q21 O12 255 grat wo oes Re R12 | R13 R3 $ WA Primary 2k 3k R14 R15 Video r{os 150 150 Qi7 P f > 4 Output wt we P J R27 $ R28 } a5 12k 10.75k R4 Q2 Q3 a4 Qi 680 R18 Rig R20 530 1k R24 25 R26 ge ok 2.5k 8k R21 R22 2.5k K p95 25k GND = = = = => = = => =F = => = MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA 9-30MC1330A ELECTRICAL CHARACTERICISTICS (Voc = +20 Vde, Q = 40, fg = 45.75 MHz, Ta = +25C, unless otherwise noted.) Characteristics Pin Min Typ Max Unit Zero Signal DC Output Voltage 4 7.0 ~~ 8.7 Vde Supply Current 5,6 1 17.5 24 mA Maximum Signal DC Output Voltage 4 _ 0 0.5 Vde Conversion Gain for 1.0 Vp-p Output (30% Modulation) 7 25 36 65 mVrms AFT Buffer Output at Carrier Frequency 1 300 475 650 mVp-p DESIGN CHARACTERISTICS (Vcc = +20 Vdc, Q = 40, fg = 45.75 MHz, Ta = +25C, unless otherwise noted.) Characteristics Pin Typ Unit Input Resistance 7 49 kQ Input Capacitance 7 15 pF Internal Resistance (Across Tuned Circuit) 2,3 44 kQ Intemal Capacitance (Across Tuned Circuit) 2,3 1.0 pF Negative Video Output Bandwidth (Figure10) 4 10.8 MHz Positive Video Output Bandwidth (Figure10) 5 2.2 MHz Differential Phase @ 3.58 MHz, 100% Modulated 4 7.0 Degrees Staircase, 3.0 Vp-p Detected Video Pin 5 Tied to Pin 6 Differential Gain @ 3.58 MHz, 100% Modulated 4 4.0 % Staircase, 3.0 Vp-p Detected Video Pin 5 Tied to Pin 6 Differential Phase @ 3.58 MHz, 100% Modulated 4 8.0 Degrees Staircase, 3.0 Vp-p Detected Video, R Pin 5 = 4.3 kQ Differential Gain @ 3.58 MHz, 100% Modulated 4 6.0 %o Staircase, 3.0 Vp-p Detected Video, R Pin 5 = 4.3 kQ 920 kHz Beat Output (dB Below 100% Modulated Video, see Figure 11) 4 38 dB 45.75 MHz = Reference 42.17 MHz = -6.0 dB 41.25 MHz = -20 dB Video Output Resistance @ 1.0 MHz, 2.0 mA 4 94 Q Input Overload (Carrier Level at Input to Pin 4, Primary Voc = 12 Vde 7 2.0 Vv Output to go Positive 0.1 Vdc from Ground.) Voc = 15 Vde 2.6 Voc = 20 Vde 3.6 Voc = 24 Vde 46 Power Supply Voltage Range 5 10 to 24 v Figure 2. Test Fixture Circuit Cartier Input 50 MC1330AP 1 2 3 4 AFT Output ut Primary Output 3.9K 3.3k GiMC1330A Figure 3. input Admittance S a e = gil gi1, b11 (mmhos) cS o11 1.0 3.0 50 100 5.0 10 FREQUENCY (MHz) Figure 4. Video Detector Output Resistance VIDEO OUTPUT RESISTNACE, PIN 4 (Q ) 10 03 0.5 1 3 VIDEO OUTPUT CURRENT, PIN 4 (mAdc) CIRCUIT DESCRIPTION The MC1330A video detector is a fully balanced multiplier detector circuit that has linear amplitude and phase character- istics. The signal is divided into two channels, one a linear amplifier and the other a limiting amplifier that provides the switching carrier for the detector. The switching carrier has a buffered output for use in providing the AFT function. The video amplifier output is an improved design that reduces the differential gain and phase distortion associated with previous video output systems. The output is wideband, > 8.0 MHz, with normal negative polarity. A separate narrow bandwidth, positive video output is also provided. Figure 5. Differential Phase and Gain Test Set Up Modulation Adjust for Monitor OV to 3V Peak Tektronix 475 at Output of 50 Oscilloscope Video Demodulator Balanced 10 dB 10 dB = Modulator 502 502 [}_OO0} | Anzac A Variabl Pad MD-141 Pad 4.4mV Lo | Into Load 50 a aie i 2nd & 3rd = Harmonic ; 100 mV Into ca 0 Load Trap Boonton 91D 6.8k ~ Wideband Amplifier Modulation 6.0 dB H.P 8447F 7500 Adjustment 300 Ay = 26dB = 67 4B = -11 V for 100% t r a Video 45.75 MHz Demodulator 75Q re a Variable Rload ~ Sk Typ Pad Low Capacitance Resistor Probe Divider H.P 100204 Six Step Modulated S Staircase Vector Scone Generator Tektronix. Vector Scope Tektronix Subearrier 520 NTSC P 144 NTSC MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA 9-32MC1330A Figure 6. Output Voltage Transfer Function s = wT = a w 5 $ 5 5 0 2 4 6 8 10 12 14 16 CARRIER INPUT VOLTAGE (mVrms) 10 26 _ 9 24 a z > 3 6 ae ~ 2 5 = ? 20 iw a wi 6 186 5 5 s & Bs 16 oO > Oo > 4 14 > & Output Voltage = Ee: Amen 25 1 Supply Curent, 8 i 9 - 6 8 10 12 14 16 18 20 22 24 SUPPLY VOLTAGE (Vdc) Figure 10. Video Output Response Figure 7. Output Voltage Transfer Function See Figure 6 ow nun Oo & Voc = 10 Vde 20 140 = 160 40 60 80 100-120 CARRIER INPUT VOLTAGE (mVrms) Figure 9. AFT Limiting 5 10 2 30)(SO0 CARRIER INPUT (mVrms) 100 Figure 11. Video Output Products : : a = 3.58 MHz Output Pin 4 Negative Video = 45.75 MHz Input = 25 mVrms s Rein 5 = 0 2 42.17 MHZ Input = 12.5 mVrms z 3 41.25 MHz Input = Relative to MHz Input = z 3 E 4.5 MHz bk = 2 a 5 w Ww = Ee a Q=60 Q=2]Q-e[a-40 O= 0 2 4 6 8 10 612 014sS8 -10 -20 -30 ~40 -50 VIDEO OUTPUT RESPONSE (MHz} RELATIVE 41.25 MHz INPUT LEVEL (dB) MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA 9-33MC1330A GENERAL INFORMATION The MC1330A offers the designer a new approach to an old problem. Now linear detection can be performed at much lower power signal levels than possible with a detector diode. Offering a number of distinct advantages, its easy imple- mentation should meet with ready acceptance for television designs. Some specific features and information on systems design with this device are given below: 1. The device provides excellent linearity of output versus input, as shown in Figures 6 and 7. These graphs also show that video peak-to-peak amplitude (AC) does not change with supply voltage variation. (Slopes are parallel. Visualize a given variation of input CW and use the figure as a transfer function.) 2. The DC output level does change linearly with supply voltage shown if Figure 8. This can be accommadated by regulating the supply or by referencing the subsequent video amplifier to the same power supply. 3. The choice of Q for the tuned circuit of Pin 2 and 3 is not critical. The higher the Q, the better the rejection of 920 kHz products by the more critical the tuning accuracy required (see Figure 11). Values of Q from 20 to 50 are recommended. (Note the internal resistance.) 4. A video output with positive-going sync is available at Pin if required. This signal has a higher output impedance than Pin 4 so it must be handled with greater care. If not used, Pin 5 may be connected directly to the supply voltage (Pin 6). The video response will be altered somewhat (see Figure 10). 5. An AFT output (Pin 1) provides 460 mV of IF carrier output, sufficient voltage to drive an AFT ratio detector, with only one additional stage. 6. AGC lockout can occur if the input signal presented in the MC1330A is greater than that shown in the input overload section of the design characteristics shown on Page 3. If these values are exceeded, the turns ratio between the primary and secondary of Ty should be increased. Another solution to the problem is to use an input clamp diode Dj shown if Figure 14. 7. The total |.F. noise figure at high gain reductions can be improved by reflecting = 1.0 k source impedance to the input of the MC1330A. This will cause some loss in overall IF voltage gain. TV-IF AMPLIFIER INFORMATION A very compact high performance IF amplifier constructed as shown in Figure 14 minimizes the number of overall components and alignment adjustments. it can be readily combined with normal tuners and input tuning-trapping circuitry to provide the performance demanded of high quality receivers. This configuration will provide approximately 93 dB voltage gain and can accommodate the usual low impedance input network or, if desired, can take advantage of an impedance step-up from tuner to MC1350 input. The burden of selectivity, formerly found between the third IF and detector, must now be placed at the interstage. The nominal 3.0 V peak-to-peak output can be varied from 0 V to 7.0 V with excellent linearity and freedom from spurious output products. Alignment is most easily accomplished with an AM genera- tor, set at a carrier frequency of 45.75 MHz, modulated with a video frequency sweep. This provides the proper realistic Figure 12. Band Pass Displayed by Conventional Sweep conditions necessary to operate to low-level detector ({LLD). The detector tank is first adjusted for maximum detected DC (with a CW input). Next, the video sweep modulation is applied and the interstage and input circuits aligned, step by step, as in a standard IF amplifier. Note: A normal IF sweep generator, essentially an FM generator, will not serve properly without modification. The LLD tank attempts to follow the sweep input frequency, and results in variations of switching amplitude in the detector. Hence, the apparent overall response becomes modified by ihe response of the LLD tank, which a real signal doesnt do. This effect can be prevented by resistively adding a 45.75 MHz CW signal to the output of the sweep generator approximately 3.0 dB greater than the sweep amplitude. See Figures 12 and 13 below. For a more detailed description of ihe MC1330A see application note ANS545A. Figure 13. Band Pass Display with the Addition of Carrier Injection MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA 9-34MC1330A Figure 14. Typical Application of MC1350P Video if Amplifier and MC1330A Low-Level Video Detector Circuit C6 Ra Ra 0.002nF 479 220 +18Vde Tt e - 18V _ 4 0.002 C12 Auxiliary Video Q = uF | T OtpF Cit 3.3k Output vl hw 68pr tov-_ - 4 0.001pF + ro 7 | | ? lar Primary Vi ry Video 4 3 2 Q 1 7 6 5 4 and Sound Output M1 WE - 4SMHz R2 MC1350 MC13304 3.9 Ly Input R7 0 C13 OpF BO 3D amr O2 O14 t~@ AFT Output 3.9k 3 4 | 5 R6 4 Tums 16 All windings #30 AWG tinned nyion acetate L1 wound with #26 AWG tinned nylon wire tuned with Carbonyl E or J slugs. acetate wire tuned by distorting winding. Figure 15. Printed Circuit Board (Parts Layout) Figure 16. Printed Circuit (Board Layout) MC1360P COPPER SIDE UP COPPER SIDE UP MOTOROLA LINEAR/INTERFACE ICs DEVICE DATA 9-35