Order this document by MC33110/D The MC33110 contains two variable gain circuits configured for compressing and expanding the dynamic range of an audio signal. One circuit is configured as an expander, while the other circuit can be configured as a compressor or expander. Each circuit has a full wave rectifier to provide average value information to a variable gain cell located in either the input stage or the feedback path. An internal, temperature stable bandgap reference provides the necessary precision voltages and currents required. The MC33110 will operate from a supply voltage of 2.1 to 7.0 V, over a temperature range of –40 to 85°C. The device is designed to accommodate an 80 dB dynamic range from –60 dB to 20 dB, referenced to 100 mVrms. Applications include cordless telephone, CB, walkie–talkie, most voice RF links, and any application where the signal–to–noise ratio can be improved by reducing the transmitted dynamic range. Other applications include speakerphone and voice activated intercom, dictating machine, standard telephone, etc. The MC33110 is packaged in a 14 pin DIP for through–the–hole applications and an SO–14 surface mount. • • • • • • • • LOW VOLTAGE COMPANDER SEMICONDUCTOR TECHNICAL DATA 14 1 Operating Supply Voltage: 2.1 to 7.0 V D SUFFIX PLASTIC PACKAGE CASE 751A (SO–14) No Precision External Components Required 80 dB Dynamic Range Compressed to 40 dB, Re–expandable to 80 dB Unity Gain Level: 100 mVrms Adjustable Response Time Ambient Operating Temperature: –40 to 85°C Temperature Compensated Reference 14 Applications Include Cordless Phone, CB Radio, Speakerphone, etc. 1 P SUFFIX PLASTIC PACKAGE CASE 646 PIN CONNECTIONS Vref NC Exp Filter Exp Output Exp Input VB Gnd Simplified Block Diagram 3 Rectifier 2.2 µF Exp Input 5 Exp. 4 Output 14 VCC VB 6 10 µF 7 Gnd 4.7 k 12 ∆ Gain Rectifier 10 k 10 k 4.7 k – + ∆ Gain VB Bias & Reference Generator VB 2.2 µF 10 k 13 3 12 4 11 5 10 6 9 7 8 VCC NC Comp Filter Comp Output Comp Input Inv Input Comp Feedback (Top View) 11 2.0 µF Comp Output 9 20 k 1.0 µF 10 20 k Comp Input ORDERING INFORMATION Device MC33110D MC33110P Operating Temperature Range TA = –40 to 85°C Motorola, Inc. 1998 MOTOROLA RF/IF DEVICE DATA 14 2 8 10 k – + 1 Package SO–14 Plastic DIP Rev 1 1 MC33110 PIN DESCRIPTION Name Pin Vref 1 Description NC 2, 13 Expander Filter 3 Connect to an external capacitor to filter the full wave rectifier’s output. This capacitor affects attack and decay times, as well as low frequency accuracy. Expander Output 4 Output of the expander amplifier. Expander Input 5 The input impedance is nominally 3.2 kΩ. Nominal signal range is 3.16 mVrms to 316 mVrms. Must be capacitor coupled to the signal source. VB 6 An internal reference voltage, nominally VCC/2. This is an ac ground and must be well filtered to obtain high power supply rejection and low crosstalk. Ground 7 Connect to a clean power supply ground. Compressor Feedback 8 Input to the compressor variable gain stage and rectifier. Normally the signal is supplied by the compressor’s output (Pin 11). Input impedance is nominally 3.2 kΩ. Inverting Input 9 Inverting input to the compressor amplifier. Normally, this is connected to the compressor’s output through a filtered dc feedback path. Compressor Input 10 The input impedance is nominally 10 kΩ. Nominal signal range is 100 µVrms to 1.0 Vrms. Must be capacitor coupled to the signal source. Compressor Output 11 Output of the compressor amplifier. Compressor Filter 12 Connect to an external capacitor to filter the full wave rectifier’s output. This capacitor affects attack & decay times, and low frequency accuracy. VCC 14 Power supply pin. Connect to a power supply providing between 2.1 V and 7.0 V. Nominal current consumption is 3.5 mA. Normally this pin is not used and is left open. It can be used to make limited adjustments to the 0 dB level. Any noise or leakage at this pin will affect the 0 dB level and gain tracking. No connection. These pins are not internally connected. Compressor Transfer Functions Compression Rectifier R5 R6 ∆ Gain Iref VB Vin – + 0 dB Vout R4 Ǹ + R5 x R67.2 xx IR4ref x Vin + 0.3162 x ǸVin 100 mV – 60 dB Vin R2 ∆ Gain VB 31.6 mV 10 mV 10 mV 3.16 mV – 30 dB – 50 dB RS 316 mV – 10 dB – 40 dB Expansion 1.0 V 10 dB – 20 dB Vout 2 20 dB Expander – + Vout Iref R1 Rectifier 1.0 mV 100 µV (Voltages are rms) Vout + 7.2R1 xx R3R2 xx VIrefin2 + 10 x Vin2 MOTOROLA RF/IF DEVICE DATA MC33110 ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁ MAXIMUM RATINGS Symbol Value Unit VCC Supply Voltage Rating VCC 12, –0.5 Vdc High Input Voltage (Pin 5 & 10) VIH VCC + 0.5 Vdc Low Input Voltage VIL –0.5 Vdc Output Source Current (Pin 4 & 11) IO+ Self–Limiting Output Sink Current IO– 20 mA Junction Temperature TJ –65, 150 °C NOTES: 1. Devices should not be operated at these values. The “Recommended Operating Conditions” table provides conditions for actual device operation. 2. ESD data available upon request. RECOMMENDED OPERATING CONDITIONS Characteristic Symbol Min Typ Max Unit VCC Supply Voltage VCC 2.1 – 7.0 Vdc Input Voltage Range Compressor, 2.1 V < VCC < 7.0 V Expander, VCC = 2.1 V Expander, 3.0 V < VCC < 7.0 V VIR 0 0 0 – – – 1.0 0.25 0.316 Input Frequency Fin 100 – 20 k Output Load Compressor (Pin 11, VO = 100 mV) Expander (Pin 4, VO = 100 mV) RL 300 150 – – ∞ ∞ Ambient Temperature TA –40 – 85 °C Unit Vrms Hz Ω All limits are not necessarily functional concurrently. ELECTRICAL CHARACTERISTICS (VCC = 5.0 V, f = 1.0 kHz, unless otherwise noted, TA = 25°C, see Figure 1) Characteristic Symbol Min Typ Max – – 3.5 3.3 5.5 – 2.4 – 2.5 VCC/2 2.6 – –1.5 0 1.5 9.0 – – –31 10 –10 –20 –30 11 – – –29 0 0.1 1.5 – 22 – POWER SUPPLY Power Supply Current VCC = 5.0 V VCC = 2.1 V ICC VB Voltage VCC = 5.0 V 2.1 V < VCC < 7.0 V VB mA Vdc COMPRESSOR 0 dB Gain Vin = 100 mVrms, Pin 1 = Open G(CO) Gain Tracking @ Vin = 1.0 Vrms, output relative to G(CO) @ Vin = 10 mVrms, output relative to G(CO) @ Vin = 1.0 mVrms, output relative to G(CO) @ Vin = 100 µVrms, output relative to G(CO) dB Gt Total Harmonic Distortion Vin = 100 mVrms, f = 1.0 kHz dB THD % Power Supply Rejection f = 1.0 kHz, CVB = 10 µF, Vin = – 20 dB PSRR Attack Time (Capacitor @ Pin 12 = 2.2 µF) ta(C) – 6.0 – ms Decay Time (Capacitor @ Pin 12 = 2.2 µF) td(C) – 20 – ms Rin – – 10 3.2 – – kΩ Input Impedance MOTOROLA RF/IF DEVICE DATA Pin 10 Pin 8 dB 3 MC33110 ELECTRICAL CHARACTERISTICS (VCC = 5.0 V, f = 1.0 kHz, unless otherwise noted, TA = 25°C, see Figure 1) Characteristic Symbol Min Typ Max Unit Ipk – 0.3 – mA –150 – 0 50 150 – –1.5 0 1.5 19 – – –61 + 20 – 20 – 40 – 60 21 – – –59 0 0.06 1.5 PSRR – 37 – dB ta(E) – 19 – ms COMPRESSOR Peak Output Current Pin 11 Output Offset Pin 11, with respect to Pin 6, NO SIGNAL Change from NO SIGNAL to 1.0 Vrms at Input VOO mVdc EXPANDER 0 dB Gain (Vin = 100 mVrms, Pin 1 = open) G(EO) Gain Tracking @ Vin = 316 mVrms, output relative to G(EO) @ Vin = 31.6 mVrms, output relative to G(EO) @ Vin = 10 mVrms, output relative to G(EO) @ Vin = 3.16 mVrms, output relative to G(EO) dB Gt Total Harmonic Distortion Vin = 100 mVrms, f = 1.0 kHz dB THD Power Supply Rejection (f = 1.0 kHz, CVB = 10 µF) Attack Time (Capacitor @ Pin 3 = 2.2 µF) Decay Time (Capacitor @ Pin 3 = 2.2 µF) % td(E) – 20 – ms Input Impedance Pin 5 Rin – 3.2 – kΩ Peak Output Current Pin 4 Ipk – 1.0 – mA –150 – 0 25 150 – –2.5 –2.5 –2.5 0 0 0 2.5 2.5 2.5 Output Offset Pin 4, with respect to Pin 6, NO SIGNAL Change from NO SIGNAL to 316 mVrms at Input VOO mVdc MISCELLANEOUS Gain (Pin 10 to Pin 4; Pin 11 capacitor coupled to Pin 5) VCC = 7.0 V, Vin = 1.0 Vrms VCC = 3.0 V, Vin = 1.0 Vrms VCC = 2.1 V, Vin = 31.6 mVrms AV Channel Separation Expander to Compressor, output measured at Pin 11 Vin @ Pin 5 = 316 mVrms, f = 1.0 kHz Vin @ Pin 5 = 316 mVrms, f = 10 kHz CS dB dB Compressor to Expander, output measured at Pin 4 Vin @ Pin 10 = 1.0 Vrms, f = 1.0 kHz Vin @ Pin 10 = 1.0 Vrms, f = 10 kHz 43 – 48 68 – – 65 – 107 114 – – Figure 1. Test Circuit 12 3 Rectifier 2.2 µF 5 Expander Input 2 µF 4.7 k Rectifier ∆ Gain 10 k ∆ Gain 4.7 k 2.2 µF 8 10 k 4 Expander Output VB – + – + 11 VB 9 5.0 k 10 k Bias & Reference Generator 3.0 µF 14 4 7 4.7 µF 10 5.0 k 3.0 µF 10 k 10 k 1.0 µF 2.0 µF VB VCC Compressor Output 1.0 µF 10 k 6 Compressor Input 4.7 µF MOTOROLA RF/IF DEVICE DATA MC33110 Compressor Expander Figure 3. Expander Transfer Characteristics Figure 2. Compressor Transfer Characteristics 1000 Vout , OUTPUT VOLTAGE (mVrms) Vout , OUTPUT VOLTAGE (mVrms) 1000 100 10 1.0 0.1 1.0 10 100 Vin, INPUT VOLTAGE (mVrms) 100 10 1.0 0.1 1000 1.0 10 100 Vin, INPUT VOLTAGE (mVrms) Figure 4. Compressor Transfer Characteristics Figure 5. Expander Transfer Characteristics 20 Vout , OUTPUT VOLTAGE (dB) Vout , OUTPUT VOLTAGE (dB) 10 0 –10 –20 0 dB = 100 mVrms –30 –60 –40 –20 Vin, INPUT VOLTAGE (dB) 0 0 –20 –40 0 dB = 100 mVrms –60 –30 +20 30 40 CVB = 220 µF 20 CVB = 100 µF 10 CVB = 47 µF 0 CVB = 10 µF 10 100 Pin 10 Input Signal = 0 mV VCC = 5.0 V 1.0 k f, FREQUENCY (Hz) MOTOROLA RF/IF DEVICE DATA 10 k –10 Vin, INPUT VOLTAGE (dB) 0 +10 CVB = 220 µF CVB = 100 µF 30 CVB = 47 µF 20 CVB = 10 µF 10 100 k –20 Figure 7. Power Supply Rejection (Expander) 50 REJECTION (dB) REJECTION (dB) Figure 6. Power Supply Rejection (Compressor) 40 –10 1000 0 10 100 Pin 5 Input Signal = 0 mV VCC = 5.0 V 1.0 k f, FREQUENCY (Hz) 10 k 100 k 5 MC33110 Compressor Expander Figure 9. Power Supply Rejection (Expander) Figure 8. Power Supply Rejection (Compressor) 40 50 20 REJECTION (dB) REJECTION (dB) CVB = 220 µF CVB = 100 µF 10 CVB = 47 µF Pin 10 Input Signal = –20 dB VCC = 5.0 V 0 CVB = 10 µF –10 CVB = 220 µF 40 30 10 100 1.0 k f, FREQUENCY (Hz) 10 k CVB = 100 µF 30 CVB = 47 µF 20 0 100 k 10 Figure 10. Frequency Response (Compressor) Vin = 100 mVrms OUTPUT RELATIVE TO INPUT (dB) OUTPUT RELATIVE TO INPUT (dB) 1.0 k f, FREQUENCY (Hz) 10 k 100 k 11 –1.0 –3.0 –5.0 –7.0 –9.0 Vin = 1.0 Vrms –11 100 1.0 k 10 k f, FREQUENCY (Hz) 20 k 7.0 5.0 3.0 1.0 Figure 12. Frequency Response (Compressor) Vin = 100 µVrms Vin = 1.0 mVrms 10 0 100 1.0 k 10 k f, FREQUENCY (Hz) 20 k 100 k Figure 13. Frequency Response (Expander) OUTPUT RELATIVE TO INPUT (dB) 40 20 Vin = 100 mVrms 0 50 30 Vin = 316 mVrms 9.0 –1.0 100 100 k 60 OUTPUT RELATIVE TO INPUT (dB) 100 Figure 11. Frequency Response (Expander) 1.0 1.0 k 10 k f, FREQUENCY (Hz) 6 Pin 5 Input Signal = –10 dB VCC = 5.0 V CVB = 10 µF 10 20 k 100 k –10 –20 –30 Vin = 10 mVrms Vin = 3.16 mVrms –40 –50 –60 100 1.0 k 10 k 20 k 100 k f, FREQUENCY (Hz) MOTOROLA RF/IF DEVICE DATA MC33110 Figure 15. Attack and Decay Times (Expander) 100 80 80 MILLISECONDS (ms) MILLISECONDS (ms) Figure 14. Attack and Decay Times (Compressor) 100 60 Decay Time 40 Attack Time 20 60 40 20 0 0 0 2.0 4.0 6.0 8.0 10 0 C, CAPACITANCE AT PIN 12 (µF) ∆V1 8.0 10 Figure 17. Attack and Decay Times (Expander) ∆V1 ∆V2 Output (Pin 4) ∆V2 Input (Pin 10) Input (Pin 5) Attack Time = Time to 63% of ∆V1. Decay Time = Time to 63% of ∆V2. Attack Time = Time to 63% of ∆V1. Decay Time = Time to 63% of ∆V2. Figure 18. Maximum Input Signal Figure 19. Channel Separation 3.0 120 Compressor To Expander 100 Compressor 2.0 SEPARATION (dB) V in , INPUT VOLTAGE (Vrms) 6.0 C, CAPACITANCE AT PIN 3 (µF) Figure 16. Attack and Decay Times (Compressor) Output (Pin 11) 4.0 2.0 1.0 80 60 Expander 0 2.0 3.0 4.0 5.0 VCC, SUPPLY VOLTAGE (V) MOTOROLA RF/IF DEVICE DATA 6.0 7.0 40 100 Expander To Compressor 1.0 k 10 k 20 k 100 k f, FREQUENCY (Hz) 7 MC33110 Compressor Expander Figure 20. Compressor Gain Tracking versus Temperature Figure 21. Expander Gain Tracking versus Temperature 1.0 GAIN DRIFT versus +25°C (dB) GAIN DRIFT versus +25°C (dB) 1.0 0 Shaded Area Depicts Typical Drift Range 100 µVrms ≤ Vin ≤ 1 Vrms –1.0 –40 –20 20 0 40 60 TA, AMBIENT TEMPERATURE (°C) 85 0 Shaded Area Depicts Typical Drift Range 3.16 mVrms ≤ Vin ≤ 316 mVrms –1.0 –40 Figure 22. Compressor THD versus Temperature 85 20 THD DRIFT versus +25° C (%%) THD DRIFT versus +25° C (%%) 20 0 40 60 TA, AMBIENT TEMPERATURE (°C) Figure 23. Expander THD versus Temperature 10 0 –10 –40 –20 –20 0 20 40 60 TA, AMBIENT TEMPERATURE (°C) 85 0 –20 –40 –20 0 20 40 60 TA, AMBIENT TEMPERATURE (°C) 85 FUNCTIONAL DESCRIPTION Introduction The MC33110 compander (COMpressor and exPANDER) is composed of two variable gain circuits which provide compression and expansion of the signal dynamic range. The compressor will take a signal with an 80 dB dynamic range (100 µV to 1.0 Vrms), and reduce that to a 40 dB dynamic range by attenuating strong signals, while amplifying low level signals. The expander does the opposite in that the 40 dB signal range is increased to a dynamic range of 80 dB by amplifying strong signals and attenuating 8 low level signals. The 0 dB level is internally set at 100 mVrms — that is the signal level which is neither amplified nor attenuated. Both circuits contain the necessary precision full wave rectifier, variable gain cell, and temperature compensated references required for accurate and stable performance. Note: All dB values mentioned in this data sheet, unless otherwise noted, are referred to 100 mVrms. MOTOROLA RF/IF DEVICE DATA MC33110 Figure 24. Compressor 4.7 k 12 2.2 µF Rectifier IControl Iref 10 k ∆ Gain 8 2.0 µF VCC Input 10 – 11 10 k VB + 9 20 k R2 Compressor The compressor is an operational amplifier with a fixed input resistor and a variable gain cell in its feedback path as shown in Figure 24. The amplifier output is sampled by the precision rectifier which, in turn, supplies a DC signal (IControl), representative of the rectifier’s AC signal, to the variable gain cell. The reference current (Iref) is an internally generated precision current. The effective impedance of the variable gain cell varies with the ratio of the two currents, and decreases as IControl increases, thereby providing compression. The output is related to the input by the following equation: Vout = 0.3162 x √Vin (Equation 1) In terms of dB levels, the relationship is: Vout(dB) = 0.5 x Vin(dB) (Equation 2) where 0 dB = 100 mVrms (see Figure 2 and 4). The inputs and output are internally biased at VB (VCC/2), and must therefore be capacitor coupled to external circuitry. Pin 10 input impedance is nominally 10 kΩ (± 20%), and the maximum functional input signal is shown in Figure 18. Bias currents required by the op amp and the variable gain cell are internally supplied. Due to clamp diodes at the input (to VCC and ground), the input signal must be maintained between the supply rails. If the input signal goes more than 0.5 V above VCC or below ground, excessive currents will flow and distortion will show up at the output. When no AC signals are present at the input, the variable gain cell will attempt to set such a high gain that the circuit may be come unstable. For this reason resistors R1 and R2, MOTOROLA RF/IF DEVICE DATA Output 20 k R1 1.0 µF C1 and capacitor C1 are added to provide DC stability. The pole formed by R1, R2 and C1 should have a pole frequency no more than 1/10th of the lowest frequency of interest. The pole frequency is calculated from: f ) R2 + 2p R1 x R1 R2 C3 (Equation 3) for the component values shown, the pole frequency is ≈ 16 Hz. Likewise, the capacitor between Pins 11 and 8 should be selected such that, in conjunction with the input impedance at Pin 8 (≈ 3200 Ω, ± 20%), the resulting pole frequency is no more than 1/10 of the lowest frequency of interest. With the components shown, the pole frequency is < 30 Hz. This pole frequency is calculated from: f 1 + 2p x 3.2 k x C (Equation 4) The output of the rectifier is filtered by the capacitor at Pin 12, which, in conjunction with an internal 10 k resistor, provides the time constant for the attack and decay times. Figure 14 and 16 indicate how the times vary with the capacitor value. The attack time for the compressor is always faster than the decay time due to the fact that the rectifier is fed from the output rather than the input. Since the output is initially larger than expected (immediately after the input has increased), the external capacitor is charged more quickly during the initial part of the time constant. When the input is decreased, the time constant is closer to that calculated by t = RC. If the attack and decay times are decreased by using a smaller capacitor, performance at low frequencies will degrade. 9 MC33110 Figure 25. Expander 3 4.7 k 2.2 µF Rectifier VCC Input 5 10 k IControl 10 k ∆ Gain – VB 4 Output + Iref Expander The expander is an operational amplifier with a fixed feedback resistor and a variable gain cell in its input path as shown in Figure 25. The input signal is sampled by the precision rectifier which, in turn, supplies a dc signal (I Control), representative of the ac input signal, to the variable gain cell. The reference current (I ref) is an internally generated precision current. The effective impedance of the variable gain cell varies with the ratio of the two currents, and decreases as I Control increases, thereby providing expansion. The output is related to the input by the following equation: Vout = 10 x (Vin)2 (Equation 5) In terms of dB levels, the relationship is: Vout(dB) = 2.0 x Vin(dB) (Equation 6) where 0 dB = 100 mVrms (see Figure 3 and 5). The inputs and output are internally biased at VB(VCC/2), and must therefore be capacitor coupled to external circuitry. The input impedance at Pin 5 is nominally 3.2 kΩ (±20%), and the maximum functional input signal is shown in Figure 18. Bias currents required by the op amp and the variable gain cell are internally supplied. Due to clamp diodes 10 at the input (to VCC and ground), the input signal must be maintained between the supply rails. If the input signal goes more than 0.5 V above VCC or below ground, excessive currents will flow, and distortion will show up at the output. The output of the rectifier is filtered by the capacitor at Pin 3, which, in conjunction with an internal 10 k resistor, provides the time constant for the attack and decay times. Figure 15 and 17 indicate how the times vary with the capacitor value. If the attack and decay times are decreased by using a smaller capacitor, performance at low frequencies will degrade. Power Supply The MC33110 requires a power supply voltage between 2.1 V and 7.0 V, and a nominal current of 3.5 mA. The supply voltage should be well filtered and free of ripple. A minimum of 4.7 µF in parallel with a 0.01 µF capacitor is recommended for filtering and RF bypass. VB (Pin 6) is an internally generated mid supply reference, and is used internally as an ac ground. The external capacitor at Pin 6 filters this voltage, and its value affects the power supply noise rejection as shown in Figures 6 through 9. This reference voltage may be used to bias external circuitry as long as the current draw is limited to <10 µA. MOTOROLA RF/IF DEVICE DATA MC33110 APPLICATIONS INFORMATION system transmitter and receiver. The MC33110 was designed for a two–to–one compression and expansion, i.e. an 80 dB dynamic signal is compressed to a 40 dB dynamic range, transmitted to the receiving end and then expanded back to an 80 dB dynamic range. The MC33110 compander is not limited to RF or long distance telephony applications. It can be used in any system requiring an improved signal–to–noise ratio such as telephones, speakerphones, tape recorders, digital recording, and many others. Signal–to–Noise Improvement Among the basic reasons for the original development of compander type circuits was to improve the signal–to–noise ratio of long distance telecom circuits, and of voice circuits which are transmitted over RF links (CBs, walkie–talkies, cordless phones, etc.). Since much of the noise heard at the receiving end of a transmission is due to noise picked up, for example, in the airway portion of the RF link, the compressor was developed to increase the low–level signals at the transmitting end. Then any noise picked in the RF link would be a smaller percentage of the transmitted signal level. At the receiving end, the signal is then expanded back to its original level, retaining the same high signal–to–noise ratio. While the above explanation indicates it is not necessary to attenuate strong signals (at the transmitting end), a benefit of doing this is the reduced dynamic range which must be handled by the Second Expander Should the application require it, the MC33110 can be configured as two expanders by reconfiguring the compressor side as shown in Figure 26. Figure 26. Second Expander 4.7 k 12 2.2 µF 9 Rectifier 10 k IControl Input 8 10 10 k ∆ Gain – VB 11 Output + Iref This circuit will provide the same performance as the expander at Pins 3 through 5. Power Supplies, Grounding The PC board layout, the quality of the power supplies and the ground system at the IC are very important in order to obtain proper operation. Noise, from any source, coming into the device on VCC or ground, can cause a distorted output, or incorrect gain level. VCC must be decoupled to the appropriate ground at the IC (within 1″ max) with a 4.7 µF capacitor and a 0.01 µF ceramic. A tantalum capacitor is recommended for the larger value if very high frequency noise is present since electrolytic capacitors simply have too much inductance at those frequencies. The quality of the power supply voltage should be checked at the IC with a high frequency scope. Noise spikes (always present if digital circuits are near this IC) can easily exceed 400 mV, and if they get into the IC, the output can have noise or distortion. Noise can be reduced by inserting resistors and/or inductors between the supply and the IC. If switching power supplies are used, there will usually be spikes of 0.5 V or greater at frequencies of 50 kHz to 1.0 MHz. These spikes are generally more difficult to reduce because of their greater energy content. In extreme cases, a MOTOROLA RF/IF DEVICE DATA three terminal regulator (MC78L05ACP), with appropriate high frequency filtering, should be used and dedicated to the analog portion of the circuit. The ripple content of the supply should not allow its magnitude to exceed the values in the Recommended Operating Conditions table. The PC board tracks supplying VCC and ground to the MC33110 should preferably not be at the tail end of the bus distribution, after passing through a maze of digital circuitry. The analog circuitry containing the MC33110 should be close to the power supply, or the connector where the supply voltages enter the board. If VCC is supplying considerable current to other parts of the board, then it is preferable to have dedicated lines from the supply or connector directly to the MC33110 and associated circuitry. PC Board Layout Although this device is intended for use in the audio frequency range, the amplifiers have a bandwidth of ≈300 kHz, and can therefore oscillate at frequencies outside the voiceband should there be excessive stray capacitance or other unintended feedback loops. A solid ground plane is 11 MC33110 strongly recommended to minimize coupling of any digital noise into the analog section. Use of wire wrapped boards should definitely be avoided. Since many applications of the MC33110 compander involve voice transmission over RF links, care must be taken in the design of the product to keep RF signals out of the MC33110 and associated circuitry. This involves proper layout of the PC boards, the physical arrangement of the boards, shielding, proper RF ground, etc. GLOSSARY Attack Time — The settling time for a circuit after its input signal has been increased. Attenuation — A decrease in magnitude of a communication signal, usually expressed in dB. Bandwidth — The range of information carrying frequencies of a communication system. Channel Separation — The ability of one circuit to reject outputting signals which are being processed by another circuit. Also referred to as crosstalk, it is usually expressed in dB. Compander — A contraction of the words compressor and expander. A compander is composed of two circuits, one of each kind. Compressor — A circuit which compresses or reduces the dynamic range of a signal by attenuating strong signals and amplifying low level signals. dB — A power or voltage measurement unit, referred to another power or voltage. It is generally computed as: 10 x log (P1/P2) for power measurements, and 20 x log (V1/V2) for voltage measurements. dBm — An indication of signal power. 1.0 mW across 600 Ω or 0.775 V rms, is typically defined as 0 dBm for telecom applications. Any voltage level is converted to dBm by: dBm = 20 x log (Vrms/0.775), or dBm = [20 x log (Vrms)] + 2.22. 12 dBrn — Indicates a dBm measurement relative to 1.0 pW power level into 600 Ω. Generally used for noise measurements, 0 dBrn = – 90 dBm. dBrnC — Indicates a dBrn measurement using a C–message weighting filter. Decay Time — The settling time for a circuit after its input signal has been decreased. Expander — A circuit which expands or increases the dynamic range of a signal by amplifying strong signals and attenuating low level signals. Gain — The change in signal amplitude (increase or decrease) after passing through an amplifier, or other circuit stage. Usually expressed in dB, an increase is a positive number and a decrease is a negative number. Power Supply Rejection Ratio — The ability of a circuit to reject outputting noise, or ripple, which is present on the power supply lines. PSRR is usually expressed in dB. Signal–to–Noise Ratio — The ratio of the desired signal to unwanted signals (noise) within a defined frequency range. The larger the number, the better. Voiceband — That portion of the audio frequency range used for transmission across the telephone system. Typically, it is 300 to 3400 Hz. MOTOROLA RF/IF DEVICE DATA MC33110 OUTLINE DIMENSIONS D SUFFIX PLASTIC PACKAGE CASE 751A-03 (SO–14) ISSUE F –A– 14 8 –B– 1 P 7 PL 0.25 (0.010) 7 G M B M R X 45 _ C F –T– M T B S A S P SUFFIX PLASTIC PACKAGE CASE 646–06 ISSUE M 14 8 1 7 B A F L C J N G D SEATING PLANE DIM A B C D F G J K M P R J M K D 14 PL 0.25 (0.010) SEATING PLANE H NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.127 (0.005) TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. K M MILLIMETERS MIN MAX 8.55 8.75 3.80 4.00 1.35 1.75 0.35 0.49 0.40 1.25 1.27 BSC 0.19 0.25 0.10 0.25 0_ 7_ 5.80 6.20 0.25 0.50 INCHES MIN MAX 0.337 0.344 0.150 0.157 0.054 0.068 0.014 0.019 0.016 0.049 0.050 BSC 0.008 0.009 0.004 0.009 0_ 7_ 0.228 0.244 0.010 0.019 NOTES: 1. LEADS WITHIN 0.13 (0.005) RADIUS OF TRUE POSITION AT SEATING PLANE AT MAXIMUM MATERIAL CONDITION. 2. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 3. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 4. ROUNDED CORNERS OPTIONAL. DIM A B C D F G H J K L M N INCHES MIN MAX 0.715 0.770 0.240 0.260 0.145 0.185 0.015 0.021 0.040 0.070 0.100 BSC 0.052 0.095 0.008 0.015 0.115 0.135 0.300 BSC 0_ 10_ 0.015 0.039 MILLIMETERS MIN MAX 18.16 19.56 6.10 6.60 3.69 4.69 0.38 0.53 1.02 1.78 2.54 BSC 1.32 2.41 0.20 0.38 2.92 3.43 7.62 BSC 0_ 10_ 0.39 1.01 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; P.O. Box 5405, Denver, Colorado 80217. 1–303–675–2140 or 1–800–441–2447 JAPAN: Nippon Motorola Ltd.; SPD, Strategic Planning Office, 141, 4–32–1 Nishi–Gotanda, Shinagawa–ku, Tokyo, Japan. 81–3–5487–8488 Customer Focus Center: 1–800–521–6274 Mfax: [email protected] – TOUCHTONE 1–602–244–6609 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, Motorola Fax Back System – US & Canada ONLY 1–800–774–1848 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298 – http://sps.motorola.com/mfax/ HOME PAGE: http://motorola.com/sps/ MOTOROLA RF/IF DEVICE DATA◊ MC33110/D 13