NOT RECOMMENDED FOR NEW DESIGNS

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1 Order this document by MC355/D The MC355 is a complete wideband FM detector designed for satellite TV and other wideband data and analog FM applications. This device may be cascaded for higher IF gain and extended Receive Signal Strength Indicator () range. 2 MHz Video/Baseband Demodulator Ideal for Wideband Data and Analog FM Systems Limiter for Cascade Operation Low Drain Current:.0 ma Low Supply Voltage: 3.0 to 6.0 V Operates to 300 MHz MAXIMUM RATINGS Rating Pin Symbol Value Unit Power Supply Voltage, 4 VEE (max) 6.5 Vdc Input Voltage, 6 Vin.0 Vrms Junction Temperature TJ +50 C Storage Temperature Range Tstg 65 to +50 C NOTE: Input Input Devices should not be operated at or outside these values. The Recommended Operating Conditions provide for actual device operation. 6 Figure. Representative Block Diagram Decouple 5 Three Stage Amplifier 2 Decouple Buffered Balanced s Limiter 0 Detector Limiter NOTE: This device requires careful layout and decoupling to ensure stable operation. 9 8 Quad Coil Device Input Decouple VCC VCC2 Limiter Out Quad Coil WIDEBAND FM IF SEMICONDUCTOR TECHNICAL DATA 6 D SUFFIX PLASTIC PACKAGE CASE 5B (SO 6) PIN CONNECTIONS (Top View) ORDERING INFORMATION Operating Temperature Range Package MC355D TA = 40 to +85 C SO Input Decouple VEE Buffer VEE2 Limiter Out Quad Coil MOTOROLA ANALOG IC DEVICE DATA Motorola, Inc. 996 Rev

2 RECOMMENDED OPERATING CONDITIONS MC355 Rating Pin Symbol Value Unit Power Supply Voltage (TA= 25 C), 4 VEE 3.0 to 6.0 Vdc 40 C TA 85 C 3, 6 VCC Grounded Maximum Input Frequency, 6 fin 300 MHz Ambient Temperature Range TJ 40 to + 85 C DC ELECTRICAL CHARACTERISTICS (TA = 25 C, no input signal.) Characteristic Pin Symbol Min Typ Max Unit Drain Current I ma (VEE = 5.0 Vdc) 4 I (VEE = 5.0 Vdc) 4 I Drain Current Total (see Figure 3), 4 ITotal ma (VEE = 5.0 Vdc) (VEE = 6.0 Vdc) (VEE = 3.0 Vdc) AC ELECTRICAL CHARACTERISTICS (TA = 25 C, fif = 0 MHz, VEE = 5.0 Vdc Figure 2, unless otherwise noted.) Characteristic Pin Min Typ Max Unit Input for 3 db Limiting Sensitivity, mvrms Differential Detector Voltage (Vin = 0 mvrms) 4, 5 mvp p (fdev = ± 3.0 MHz) (VEE = 6.0 Vdc) (VEE = 5.0 Vdc) (VEE = 3.0 Vdc) Detector DC Offset Voltage 4, mvdc Slope µa/db Dynamic Range db 2 µa (Vin = 00 µvrms) 2. (Vin =.0 mvrms) 2.4 (Vin = 0 mvrms) (Vin = 00 mvrms) 65 (Vin = 500 mvrms) 5 Buffer Maximum Current (Vin = 0 mvrms) madc Differential Limiter (Vin =.0 mvrms), (Vin = 0 mvrms) 80 Demodulator Video 3.0 db Bandwidth 4, 5 2 MHz Input Impedance (Figure 4), 0 MHz Rp (VEE = 5.0 Vdc) MHz Cp (C2=C5 = 00 p) 4.8 pf Differential IF Power Gain,, 0, 6 46 db NOTE: Positive currents are out of the pins of the device. mvrms 2 MOTOROLA ANALOG IC DEVICE DATA

3 MC355 CIRCUIT DESCRIPTION The MC355 consists of a wideband three stage limiting amplifier, a wideband quadrature detector which may be operated up to 200 MHz, and a received signal strength indicator () circuit which provides a current output linearly proportional to the IF input signal level for approximately 35 db range of input level. Vin Video Limiter Figure 2. Test Circuit DEC VCC DETO DETO2 VCC2 LIMO QUAD Evaluation PC Board The evaluation PCB shown in Figures 9 and 20 is very versatile and is designed to cascade two ICs. The center section of the board provides an area for attaching all surface mount components to the circuit side and radial leaded components to the component ground side of the PCB (see Figures and 8). Additionally, the peripheral area surrounding the RF core provides pads to add supporting and interface circuitry as a particular application dictates. This evaluation board will be discussed and referenced in this section. Limiting Amplifier Differential input and output ports interfacing the three stage limiting amplifier provide a differential power gain of typically 46 db and useable frequency range of 300 MHz. The IF gain flatness may be controlled by decoupling of the internal feedback network at Pins 2 and IN p 260n IN2 DEC2 VEE Buffer VEE2 LIMO2 QUAD2 APPLICATIONS INFORMATION L n 00n.0k 00n 2 Limiter µ 0µ L Coilcraft part number 46 09J08S + + VEE VEE VEE Scattering parameter (S parameter) characterization of the IF as a two port linear amplifier is useful to implement maximum stable power gain, input matching, and stability over a desired bandpass response and to ensure stable operation outside the bandpass as well. The MC355 is unconditionally stable over most of its useful operating frequency range; however, it can be made unconditionally stable over its entire operating range with the proper decoupling of Pins 2 and 5. Relatively small decoupling capacitors of about 00 pf have a significant effect on the wideband response and stability. This is shown in the scattering parameter tables where S parameters are shown for various values of C2 and C5 and at VEE of 3.0 and 5.0 Vdc. MOTOROLA ANALOG IC DEVICE DATA 3

4 I and I 4, TOTAL DRAIN CURRENT (madc) I 4 and I Total, DRAIN CURRENT (madc) OUTPUT ( µ A) I, Figure 3. Drain Current versus Supply Voltage TA = 25 C ITotal = I4 + I 5.0 Vdc MC355 OUTPUT ( A) 2 µ I, 40 dbm VEE, SUPPLY VOLTAGE ( Vdc) Figure 5. Total Drain Current versus Ambient Temperature and Supply Voltage I4 VEE = 6.0 Vdc TA, AMBIENT TEMPERATURE ( C) Figure. versus Ambient Temperature and Supply Voltage TYPICAL PERFORMANCE AT TEMPERATURE (See Figure 2. Test Circuit) 3.0 Vdc DRAIN CURRENT (madc) I 4 and I, Figure 4. versus Frequency and Input Signal Level 0 dbm 0 dbm 20 dbm 30 dbm f, FREQUENCY (MHz) Figure 6. Detector Drain Current and Limiter Drain Current versus Ambient Temperature VEE = 6.0 Vdc VEE = 5.0 Vdc VEE = 3.0 Vdc OUTPUT ( µ A) I, f = 0 MHz VEE = 5.0 Vdc VEE = 5.0Vdc TA, AMBIENT TEMPERATURE ( C) I4 Figure 8. versus Input Signal Voltage (Vin at Temperature) I TA = + 85 C +25 C 40 C TA, AMBIENT TEMPERATURE ( C) Vin, INPUT VOLTAGE (mvrms) 4 MOTOROLA ANALOG IC DEVICE DATA

5 MC355 DIFFERENTIAL DETECTOR OUTPUT VOLTAGE (Pins 4, 5), (mv pp ) DIFFERENTIAL DETECTOR OUTPUT (mv pp ) OUTPUT VOLTAGE, (Vdc) Figure 9. Differential Detector Voltage versus Ambient Temperature and Supply Voltage VEE = 6.0 Vdc Vdc Vdc TA, AMBIENT TEMPERATURE ( C) DIFFERENTIAL LIMITER OUTPUT VOLTAGE (Pins, 0), (mvrms) Figure 0. Differential Limiter Voltage versus Ambient Temperature (Vin = and 0 mvrms) Vin = 0 mvrms Figure A. Differential Detector Voltage versus Q of Quadrature LC Tank Vin = 30 dbm VEE = 5.0 Vdc fc = 0 MHz fmod =.0 MHz (Figure 6 no external capacitors between Pins, 8 and 9, 0) Q OF QUADRATURE LC TANK Figure. Figure 2. Voltage versus IF Input IF INPUT, (dbm) f dev = ± 6.0 MHz ± 5.0 MHz ± 4.0 MHz ± 3.0 MHz ± 2.0 MHz ±.0 MHz DIFFERENTIAL DETECTOR OUTPUT (mv pp TA, AMBIENT TEMPERATURE ( C) Q OF QUADRATURE LC TANK IF INPUT (dbm) ±.0 MHz VEE = 5.0 Vdc fc = 0 MHz (See Figure 6) Capacitively coupled interstage: no attenuation 5 db Interstage Attenuator ) S+N, N (db) f = 0 MHz VEE = 5.0 Vdc Figure B. Differential Detector Voltage versus Q of Quadrature LC Tank 2400 Vin = 30 dbm VEE = 5.0 Vdc f dev = ± 6.0 MHz 2000 fc = 0 MHz fmod =.0 MHz (Figure 6 no external capacitors ± 5.0 MHz 600 between Pins, 8 and 9, 0) ± 4.0 MHz 200 ± 3.0 MHz S+N Vin =.0 mvrms Figure 3. S+N, N versus IF Input ± 2.0 MHz fc = 0 MHz N fmod =.0 MHz 60 fdev = ± 5.0 MHz VEE = 5.0 Vdc MOTOROLA ANALOG IC DEVICE DATA 5

6 In the S parameters measurements, the IF is treated as a two port linear class A amplifier. The IF amplifier is measured with a single ended input and output configuration in which the Pins 6 and are terminated in the series combination of a 4 Ω resistor and a 0 nf capacitor to VCC ground (see Figure 4. S Parameter Test Circuit). The S parameters are in polar form as the magnitude (MAG) and angle (ANG). Also listed in the tables are the calculated values for the stability factor (K) and the Maximum IF Input SMA 4 MC355 Figure 4. S Parameter Test Circuit C IN DEC VCC DETO DETO2 VCC2 LIMO QUAD Available Gain (MAG). These terms are related in the following equations: K = ( IS I2 I S22 I2 + I I2 ) / ( 2 I S2 S2 I ) where: I I = I S S22 S2 S2 I. MAG = 0 log I S2 I / I S2 I + 0 log I K ( K2 )/2 I where: K >. The necessary and sufficient conditions for unconditional stability are given as K > : B = + I S I2 I S22 I2 I I2 > 0 IN2 DEC2 VEE Buffer VEE2 LIMO2 QUAD C5 4 SMA 00n 0µ IF + VEE 6 MOTOROLA ANALOG IC DEVICE DATA

7 MC355 S Parameters (VEE = 5.0 Vdc, TA = 25 C, C2 and C5 = 0 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db S Parameters (VEE = 5.0 Vdc, TA = 25 C, C2 and C5 = 00 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db MOTOROLA ANALOG IC DEVICE DATA

8 MC355 S Parameters (VEE = 5.0 Vdc, TA = 25 C, C2 and C5 = 680 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db S Parameters (VEE = 3.0 Vdc, TA = 25 C, C2 and C5 = 0 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db MOTOROLA ANALOG IC DEVICE DATA

9 MC355 S Parameters (VEE = 3.0 Vdc, TA = 25 C, C2 and C5 = 00 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db S Parameters (VEE = 3.0 Vdc, TA = 25 C, C2 and C5 = 680 pf) Frequency Input S Forward S2 Rev S2 S22 K MAG MHz MAG ANG MAG ANG MAG ANG MAG ANG MAG db MOTOROLA ANALOG IC DEVICE DATA 9

10 DC Biasing Considerations The DC biasing scheme utilizes two VCC connections (Pins 3 and 6) and two VEE connections (Pins 4 and ). VEE (Pin 4) is connected internally to the IF and circuits negative supply bus while VEE2 (Pin ) is connected internally to the quadrature detector s negative bus. Under positive ground operation, this unique configuration offers the ability to bias the and IF separately from the quadrature detector. When two ICs are cascaded as shown in the 0 MHz application circuit and provided by the PCB (see Figures and 8), the first MC355 is used without biasing its quadrature detector, thereby saving approximately 3.0 ma. A total current of.0 ma is used to fully bias each IC, thus the total current in the application circuit is approximately ma. Both VCC pins are biased by the same supply. VCC (Pin 3) is connected internally to the positive bus of the first half of the IF limiting amplifier, while VCC2 is internally connected to the positive bus of the, the quadrature detector circuit, and the second half of the IF limiting amplifier (see Figure 5). This distribution of the VCC enhances the stability of the IC. Circuitry The circuitry provides typically 35 db of linear dynamic range and its output voltage swing is adjusted by MC355 Block Diagram of 0 MHz Video Receiver Application Circuit selection of the resistor from Pin 2 to VEE. The slope is typically 2. µa/db ; thus, for a dynamic range of 35 db, the current output is approximately 4 µa. A 4 k resistor will yield an output voltage swing of 3.5 Vdc. The buffer output at Pin 3 is an emitter follower and needs an external emitter resistor of 0 k to VEE. In a cascaded configuration (see circuit application in Figure 6), only one of the Buffer outputs (Pin 3) is used; the outputs (Pin 2 of each IC) are tied together and the one closest to the VEE supply trace is decoupled to VCC ground. The two pins are connected to VEE through a 4 k resistor. This resistor sources a current which is proportional to the signal level at the IF input; typically,.0 mvrms ( 4 dbm) is required to place the MC355 into limiting. The measured output voltage response of the application circuit is shown in Figure 2. Since the current output is dependent upon the input signal level at the IF input, a careful accounting of filter losses, matching and other losses and gains must be made in the entire receiver system. In the block diagram of the application circuit shown below, an accounting of the signal levels at points throughout the system shows how the response in Figure 2 is justified. Input 45 dbm 0 dbm 2 dbm 32 dbm 4 dbm Minimum Input to Acquire Level:.26 mvrms µvrms 5 µvrms 5 µvrms.0 mvrms Limiting in MC355 IF Input Saw Filter :4 Transformer 25 db 2.0 db (Insertion Loss) (Insertion Loss) Cascading Stages The limiting IF output is pinned out differentially, cascading is easily achieved by AC coupling stage to stage. In the evaluation PCB, AC coupling is shown, however, interstage filtering may be desirable in some applications. In which case, the S parameters provide a means to implement a low loss interstage match and better receiver sensitivity. Where a linear response of the output is desired when cascading the ICs, it is necessary to provide at least 0 db of interstage loss. Figure 2 shows the response with and without interstage loss. A 5 db resistive attenuator is an inexpensive way to linearize the response. This has its drawbacks since it is a wideband noise source that is dependent upon the source and load impedance and the amount of attenuation that it provides. A better, although more costly, solution would be a bandpass filter designed to the desired center frequency and bandpass response while carefully selecting the insertion loss. A network topology 6 MC db Gain 0 5 db (Attenuator) 6 MC db Gain shown below may be used to provide a bandpass response with the desired insertion loss µ Network Topology 6 0 MOTOROLA ANALOG IC DEVICE DATA

11 MC355 Quadrature Detector The quadrature detector is coupled to the IF with internal 2.0 pf capacitors between Pins and 8 and Pins 9 and 0. For wideband data applications, such as FM video and satellite receivers, the drive to the detector can be increased with additional external capacitors between these pins, thus, the recovered video signal level output is increased for a given bandwidth (see Figure A and Figure B). The wideband performance of the detector is controlled by the loaded Q of the LC tank circuit. The following equation defines the components which set the detector circuit s bandwidth: Q = RT/XL () where: RT is the equivalent shunt resistance across the LC Tank and XL is the reactance of the quadrature inductor at the IF frequency (XL = 2πfL). The inductor and capacitor are chosen to form a resonant LC Tank with the PCB and parasitic device capacitance at the desired IF center frequency as predicted by: fc = (2π (LCp)) (2) where: L is the parallel tank inductor and Cp is the equivalent parallel capacitance of the parallel resonant tank circuit. The following is a design example for a wideband detector at 0 MHz and a loaded Q of 5. The loaded Q of the quadrature detector is chosen somewhat less than the Q of the IF bandpass. For an IF frequency of 0 MHz and an IF bandpass of 0.9 MHz, the IF bandpass Q is approximately 6.4. Example: Let the external Cext = 20 pf. (The minimum value here should be greater than 5 pf making it greater than the internal device and PCB parasitic capacitance, Cint 3.0 pf). Cp = Cint + Cext = 23 pf Rewrite Equation 2 and solve for L: L = (0.59)2 /(Cp fc2) L = 98 nh, thus, a standard value is chosen. L = 0.22 µh (tunable shielded inductor). The value of the total damping resistor to obtain the required loaded Q of 5 can be calculated by rearranging Equation : RT = Q(2πfL) RT = 5 (2π)(0)(0.22) = Ω. The internal resistance, Rint between the quadrature tank Pins 8 and 9 is approximately 3200 Ω and is considered in determining the external resistance, Rext which is calculated from: Rext = ((RT)(Rint))/ (Rint RT) Rext = 50, thus, choose the standard value. Rext = 560 Ω. SAW Filter In wideband video data applications, the IF occupied bandwidth may be several MHz wide. A good rule of thumb is to choose the IF frequency about 0 or more times greater than the IF occupied bandwidth. The IF bandpass filter is a SAW filter in video data applications where a very selective response is needed (i.e., very sharp bandpass response). The evaluation PCB is laid out to accommodate two SAW filter package types: ) A five leaded plastic SIP package. Recommended part numbers are Siemens X6950M which operates at 0 MHz; 0.4 MHz 3 db passband, X695M (X252.8) which operates at 0 MHz; 9.2 MHz 3 db passband; and X6958M which operates at 0 MHz, 6.3 MHz 3 db passband, and 2) A four leaded TO 39 metal can package. Typical insertion loss in a wide bandpass SAW filter is 25 db. The above SAW filters require source and load impedances of 50 Ω to assure stable operation. On the PC board layout, space is provided to add a matching network, such as a :4 surface mount transformer between the SAW filter output and the input to the MC355. A :4 transformer, made by Coilcraft and Mini Circuits, provides a suitable interface (see Figures 6, and 8). In the circuit and layout, the SAW filter and the MC355 are differentially configured with interconnect traces which are equal in length and symmetrical. This balanced feed enhances RF stability, phase linearity, and noise performance. MOTOROLA ANALOG IC DEVICE DATA

12 MC355 5 Decouple Buffer VCC LIM Out Quad Coil LIM Out VCC2 0p 8.0k.0k.0k k.6k 8.0k Bias Bias Det Out 2.0p 2.0p.0p 6 4 Input Input VEE VEE 2 Figure 5. Figure 5. Simplified Internal Circuit Schematic 2 MOTOROLA ANALOG IC DEVICE DATA

13 MC355 Figure 6. 0 MHz Video Receiver Application Circuit If Input :4 Detector 2 3 SAW Filter is Siemens Part Number X6950M 00n 00n SAW Filter 33p 33p 5 4.0k.0k 00p 00p 2.0p IN DEC VCC DETO DETO2 VCC2 LIMO QUAD MC IN2 DEC2 VEE Buffer VEE2 LIMO2 QUAD n IN DEC VCC DETO DETO2 VCC2 LIMO QUAD 220 MC IN2 DEC2 VEE Buffer VEE2 LIMO2 QUAD p 0n 00p 0n 0n 2.0p 4k 0k 0µ + 00n + 0µ VEE2 VEE 20p L 0.22µ L Coilcraft part number 46 08J08S MOTOROLA ANALOG IC DEVICE DATA 3

14 MC355 Figure. Component Placement (Circuit Side) Figure 8. Component Placement (Ground Side) 4 MOTOROLA ANALOG IC DEVICE DATA

15 MC355 Figure 9. Circuit Side View 4.0 Figure 20. Ground Side View 4.0 MOTOROLA ANALOG IC DEVICE DATA 5

16 SEATING PLANE 6 G A 9 8 B P T D6 PL K 0.25 (0.00) M T B S A S MC355 OUTLINE DIMENSIONS C D SUFFIX PLASTIC PACKAGE CASE 5B (SO 6) 8 PL 0.25 (0.00) M B M M R X 45 F J NOTES:. DIMENSIONING AND TOLERANCING PER ANSI Y4.5M, CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSION A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.5 (0.006) PER SIDE. 5. 5B 03 IS OBSOLETE, NEW STANDARD 5B 04. DIM A B C D F G J K M P R MILLIMETERS MIN MAX BSC BSC INCHES MIN MAX Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including Typicals must be validated for each customer application by customer s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. Mfax is a trademark of Motorola, Inc. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; JAPAN: Nippon Motorola Ltd.: SPD, Strategic Planning Office, 4 32, P.O. Box 5405, Denver, Colorado or Nishi Gotanda, Shinagawa ku, Tokyo 4, Japan Mfax : RMFAX0@ .sps.mot.com TOUCHTONE ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, US & Canada ONLY Ting Kok Road, Tai Po, N.T., Hong Kong INTERNET: MOTOROLA ANALOG IC DEVICE MC355/D DATA

ML13155 Wideband FM IF

ML13155 Wideband FM IF Wideband FM IF SEMICONDUCTOR TECHNICAL DATA Legacy Device: Motorola MC355 The ML355 is a complete wideband FM detector designed for satellite TV and other wideband data and analog FM applications. This