U4311B Low-Current Superhet Remote Control Receiver Description The U4311B is a monolithic integrated circuit in bipolar technology for low-current UHF remote control superheterodyne receivers in amplitude- or frequencymodulated mode. Typical applications are keyless car lock-, alarm- or tele-control remote indication systems. Especially for automotive applications, it supports a superhet design with about 1 mA total current consumption as required by the car manufacturers. Features D Usable for amplitude- and frequency-modulated transmission systems D Logarithmic AM demodulator D Extremely low quiescent current (approximately 1 mA in standby mode due to wake-up concept) D Monoflop exit to wake up a microcontroller D FM demodulator D Wide power supply voltage range 3 to 13 V D High-performance operational amplifier to realize a data recovering filter D Sensitive IF amplifier for 10.7-MHz operating frequency D Non-inverting clamping comparator with amplitudedepending hysteresis for data regeneration Block Diagram Wake-up out VS 15 10 3 7 6 VRef = 2.4V 13 Bandgap 11 Internal VRef = 2.4 V Non – invert. clamping comparator Monoflop RF Level 5 Data out Wake up 10.7 MHz 9 Quadrature detector IF amplifier 4 8 12 2 Operational amplifier 14 – + 16 1 95 9968 log AM out FM out 10.7 MHz Data filter Figure 1. Block diagram Ordering Information Extended Type Number U4311B-M U4311B-MFL Rev. A3, 28-Sep-00 Package DIP16 SO16L Remarks 1 (15) U4311B Pin Description OPin+ 1 16 OPin– OPout 2 15 VS RCwake 3 14 FMout GND2 4 13 VRef Compout 5 12 Discr RC– 6 11 GND1 RC+ 7 10 SWout AMout 8 9 IFin Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Symbol OPin+ OPout RCwake GND2 Compout RC– RC+ AMout IFin SWout GND1 Discr VRef FMout VS OPin– Function OP amplifier non-inverted input OP amplifier output RC wake-up reset time Ground of the logical circuits Comparator output Comparator time constant Comparator time constant AM current output IF input Wake-up output Ground of the analog circuits FM discriminator tank Reference voltage FM discriminator output Supply voltage OP amplifier inverted input 95 10322 Figure 2. Pin description Internal connections see figures 4 to 19 Absolute Maximum Ratings Parameters Supply voltage Power dissipation Tamb = 85°C Junction temperature Ambient temperature Storage temperature Symbol VS Ptot Tj Tamb Tstg Value 13 400 125 –40 to +85 –55 to +125 Unit V mW °C °C °C Symbol RthJA RthJA Value 120 100 Unit K/W K/W Thermal Resistance Junction ambient 2 (15) Parameters DIP16 SO16L Rev. A3, 28-Sep-00 U4311B Electrical Characteristics VS = 5 V, Tamb = 25°C, fin = 10.7 MHz; FM part: fmod = 1 kHz, fdev = 22.5 kHz; AM part: fmod = 1 kHz, m = 100% unless otherwise specified Parameters Test Conditions / Pins Symbol Min. 3 Typ. Max. Unit 12 V Characteristics Supply-voltage range Pin 15 VS Quiescent supply current Pin 15 Iq 1 1.3 mA Active supply current Pin 15 Iact 2.8 3.6 mA Regulated voltage Pin 13 VRef 2.4 2.5 V Output current Pin 13 IRef 5 mA Source resistance Pin 13 RRef 5 W External capacitor Pin 13 CRef Pin 13 psrr Input resistance Pin 9 Rin Input capacitance Pin 9 Cin Bandgap Power-supply rejection ratio f = 50 Hz 2.3 2.3 mF 10 60 dB IF amplifier Typical internal 3 dB frequency IF level 70 dBmV Pins 9 and 14 f3dB 180 330 520 5 8 W pF 12 –3 dB limiting point Pin 9 VFM3dB Recovered data voltage Pin 14 VFMout FM detector output resistance Pin 14 RFMout 50 kW AMrr 25 dB 90 dBmV AM rejection ratio m = 30% Pins 9 and 14 Maximum AM input voltage Pin 9 VAMmax AM quiescent current Pin 8 IAMout Maximum AM current Pin 8 IAMoutmax 30 MHz 50 10 130 22 dBmV 230 37 mV mA mA 100 Operational amplifier Gain-bandwidth product Pins 1, 2 and 16 ft Excess phase Pins 1, 2 and 16 d Open loop gain Pins 1, 2 and 16 g0 3 6.5 80 50 ∆Vout Output voltage range Pin 2 Common-mode input voltage Pins 1 and 16 Vin 0.7 Input offset voltage Pins 1 and 16 Vos –2.5 Maximum output current Pin 2 Iout Rev. A3, 28-Sep-00 4 70 degree 95 1.55 0 MHz dB V 1.7 V +2.5 mV 5 mA 3 (15) U4311B Parameters Test Conditions / Pins Symbol Min. Typ. 65 85 Common-mode rejection ratio Pin 1 and 16 cmrr Total harmonic distortion Vin < 300 mV, f = 33 kHz, unity gain circuit Pin 2 thd 4 (15) 1 Max. Unit dB 3 % Rev. A3, 28-Sep-00 U4311B Electrical Characteristics (continued) VS = 5 V, Tamb = 25°C, fin = 10.7 MHz; FM part: fmod = 1 kHz, fdev = 22.5 kHz; AM part: fmod = 1 kHz, m = 100% unless otherwise specified Parameters Power-supply rejection ratio Test Conditions / Pins f = 50 Hz Symbol Min. Typ. Pin 2 psrr 65 85 Pin 2 Vcmvr 0.8 Max. Unit dB Clamping comparator Typical common-mode input voltage range Maximum distortion voltage Vsignal = 100 mV, R+ = R– = 50 kW, C+ = C– = 200 nF, fdisto = 50 Hz, fsignal = 1 kHz Pin 2 Vdmax Output voltage V2 > (V6 + V7) /2 (10-kW load to VRef) Pin 5 Vcout Output voltage V2 < (V6 + V7 ) /2 (10-kW load to VRef) Pin 5 Vcout 1.6 V 200 mV VRef 0 150 V 250 mV Wake-up circuit Minimum wake-up level Pin 9 Vin 40 dBmV 1) Internal charging resistor Pin 3 Rint 1.5 kW Threshold voltage Pin 3 Vth 1.6 V Output switch current Pin 10 ISW Output switch voltage Pin 10 VSW External wake-up resistor Pins 3 and 13 RWU External wake-up capacitor Pins 3 and 13 CWU Hold time (± 30%) th Delay time (± 30%) td 1) Measured at Pin 9, referred to 330 W 2) Protected by a Z-diode, see figure 13 3) Valid for 0.1 mF ≤ CWU ≤ 10 mF and 22 kW ≤ RWU ≤ 680 kW Rev. A3, 28-Sep-00 180 250 550 mA 5.5 V 2) 22 kW 10 1.5 CWU RWU CWU 0.75 kW mF s 3) s 3) 5 (15) U4311B Circuit Description General Functions The integrated circuit U4311B includes the following functions: IF amplifier, FM demodulator, wake-up circuit with monoflop, operational amplifier, non-inverting data comparator and voltage regulator. The 10.7-MHz IF signal from the front end passes the integrated IF-amplifier which operates for amplitude- or frequency-modulated signals to either a logarithmic AM demodulator which was implemented to avoid settlingtime problems effected by use of an automatic gain control system or a quadrature detector for FM. A datashaping filter * advantageously realized with the internal high-performance operational amplifier * reduces system bandwidth to an optimized compromise regarding transmission distance and data recognition. Thus, an optimal bit-error rate can be achieved without any further active component. The comparator connected to the output of the filter has a level-dependent hysteresis and clamps its reference voltage to the signal’s minimum and maximum peaks as described later. Without IF-input signal * in normal mode * only the IF amplifier and the AM demodulator which operates as a level-strength indicator are activated. If the level of the IF signal increases, the entire circuitry is turned on by the wake-up circuit. This signal is externally available at Pin 10 and can be used to wake up a microcontroller. After an adjustable reset time, determined by the monoflop time constant, the integrated circuit returns to sleep mode. In this case, typically 1-mA supply current is required. An external resistor matched at Pin 3 to ground blocks the wake-up circuit and enables the complete functionality at lower IF levels as can be seen in figures 24 and 27, but supply current increases up to typically 2.8 mA. Function of the Clamping Comparator The output signal of the operational amplifier is fed to the input of the non-inverting comparator and two peak detectors (Q1 and Q2, figure 3). Their time constants are distinguished by RC+ and RC–. The component’s value must be adapted to the transmission code. The time constant should be large compared to the bit rate for optimized noise and hum suppression. To compensate the input transistor’s base-emitter-voltage differences, these two signals are buffered by Q3 and Q4. The mean value is used as comparator threshold, the difference of the peak values controls the hysteresis. This clamping comparator operates as a data regenerator. VRef 1 2 3 4 6 5 7 8 95 9969 Q4 Q1 Q3 Q2 Hysteresis Op. amp. Comparator + – Comp. threshold to Pin 16 Figure 3. Principle function of the clamping comparator 6 (15) Rev. A3, 28-Sep-00 U4311B Internal Pin Circuitry 95 9970 4 95 9973 1 16 Figure 7. Pin 4 GND2 5 Figure 4. Pin 1 OPin+ VRef 95 9974 13 Figure 8. Pin 5 Compout 2 95 9975 13 VRef 95 9971 Figure 5. Pin 2 OPout 3 13 VRef 2 6 95 9972 Figure 6. Pin 3 RCwake Rev. A3, 28-Sep-00 Figure 9. Pin 6 RC– 7 (15) U4311B 7 95 10128 13 VRef 10 2 95 10125 Figure 10. Pin 7 RC+ Figure 13. Pin 10 SWout 13 95 10126 VRef 11 95 10129 Figure 14. Pin 11 GND1 8 12 Figure 11. Pin 8 AMout 95 10127 9 95 10130 Figure 12. Pin 9 IFin 8 (15) Figure 15. Pin 12 Discr Rev. A3, 28-Sep-00 U4311B 15 VS 15 95 10133 VRef Figure 18. Pin 15 VS 13 95 10134 95 10131 Figure 16. Pin 13 VRef 16 13 1 VRef 14 95 10132 Figure 17. Pin 14 FMout Rev. A3, 28-Sep-00 Figure 19. Pin 16 OPin– 9 (15) U4311B 0.005 1400 1300 0.004 1200 0.003 1100 0.002 Vout ( mV ) l in ( mA ) Output 1000 0.001 900 Input 0 800 15 20 25 30 35 40 Time ( ms ) 95 10333 Figure 20. Time domain response of 2-kHz Bessel lowpass data filter 100 100 dBmV Data-Recovering Filter Output current ( m A ) 80 70 dBmV 60 40 50 dBmV 20 30 dBmV 0 6 8 10 12 14 16 IF frequency ( MHz ) 95 10332 The capacitor C2 is responsible for the highpass cut-off frequency. In order to achieve a correct pulse response, this highpass cut-off frequency should be as low as possible. Figure 20 shows the transient response and the influence of the dc component. The first pulses might be wrong if the highpass cut-off frequency is too low. For this reason, some burst bits must be transmitted before the real data transmission starts. On the other hand, if the cut-off frequency is too high, roof shaping of the rectangle pulses at the operational amplifier output might causes problems. Figure 21. IF-frequency response 0 –10 V / Vmax ( dB ) The test circuit in figures 23 and 26 includes an example of a data-recovering filter realized with the components R1, R2, C1, C2, C3. It is of a second-order Bessel type with lowpass characteristic, a 3-dB cut-off frequency of 2 kHz and an additional highpass characteristic for suppressing dc and low-frequency ac components. Simulation of time domain and frequency response can be seen in figures 20 and 22. This filter gives a typical application of a 1-kBaud Manchester-code, amplitude-modulated transmission. –20 –30 –40 0.01 95 10334 0.1 1 10 100 Frequency ( kHz ) Figure 22. Frequency response of 2-kHz Bessel lowpass data filter 10 (15) The lowpass cut-off frequency and the maximum transimpedance Vout/Iin are distinguished by the further external elements. Careful design of the data filter enables optimized transmission range. For designing other filter parameters, please refer to filter design handbooks/ programs or request Atmel Wireless & Microcontrollers for support. Rev. A3, 28-Sep-00 U4311B C7 10 mF VS R9 56 W C8 100 nF IF input R10 300 W C10 10 nF C9 10 mF C11 10 nF R8 100 kW 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 Wake-up out C2 100 nF C3 1.5 nF C1 10 nF 95 10135 R1 8.2 kW R6 100 kW R12 R2 30 kW R5 100 kW C12 C4 100 nF Comparator output 100 kW 220 nF Data filter output Wake up R7 22 kW R3 220 kW R13 C5 220 nF R4 100 kW C6 220 nF 10 kW R11 10 kW 10 100 0 90 S+N –10 AM output current ( m A ) LP-filter output voltage Vs+n/Vn ( dB ) Figure 23. AM test circuit with 2-kHz Bessel lowpass data filter –20 –30 –40 N (low level) –50 –60 –70 +25°C 80 +85°C 70 60 –40°C 50 40 30 20 N (high level) –80 10 0 20 95 10292 40 60 80 IF-input level ( dmBV ) Figure 24. Signal-to-noise ratio AM Rev. A3, 28-Sep-00 100 10 95 10276 25 40 55 70 85 IF-input level (dBmV ) 100 Figure 25. AM-demodulator characteristic vs. temperature 11 (15) U4311B VS TOKO A119ACS-19000Z (L = 2.2 mH, C = 100 pF) Filter C7 10 mF R9 56 W C8 100 nF R15 22 k W R14 22 k W IF input R10 300 W C10 C9 10 mF 22 pF R8 100 k W C2 C11 10 nF 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 Wake-up out 95 10136 R1 8.2 k W 100 nF C3 1.5 nF R6 100 kW R12 C1 R2 30 k W 10 nF R5 100 k W C12 R11 C4 100 nF 10 k W 100 k W 220 nF Wake up Data filter output R7 22 kW Comparator output R4 100 kW R3 220 kW R13 10 k W C5 220 nF C6 220 nF 10 2.5 C10 = 22 pF 0 S+N 2.0 –10 Output voltage ( V ) LP-filter output voltage Vs+n/Vn ( dB ) Figure 26. FM test circuit with 2-kHz Bessel lowpass data filter –20 –30 –40 –50 –70 0 95 10291 20 40 60 80 IF-input level ( dmBV ) 100 Figure 27. Signal-to-noise ratio FM; deviation 22.5 kHz 12 (15) C10 = 47 pF 1.0 0.5 N –60 1.5 0.0 10.3 95 10290 10.5 10.7 10.9 Frequency ( MHz ) 11.1 Figure 28. FM-discriminator characteristic Rev. A3, 28-Sep-00 U4311B Application The U4311B is well-suited to implement UHF remote control or data transmission systems, based on a low-current superheterodyne receiver concept. SAW-devices may be used in the transmitter’s as well as in the receiver local oscillator. The front end should be a discrete circuit application with low-current UHF transistors such as S822T or S852T (Vishay Telefunken). The frequency of the local oscillator can be determined either by coaxial resonators or SAW devices. Due to large SAW-resonator tolerance, an IF bandwidth * and in a FM system additionally the discriminator amplitude characteristic (figure 28) * of 300 kHz or higher is proposed. As the circuit needs only 3.0 V supply voltage for operation, the front end may be a stacked design in order to achieve a total receiver current consumption of approximately 1 mA. Figure 29 shows a principle receiver concept diagram. VS 350 mA 350 mA Data out RF in 1 mA Signal path Power supply 95 10137 Figure 29. Principle diagram of a UHF remote control receiver Rev. A3, 28-Sep-00 13 (15) U4311B Package Information Package DIP16 Dimensions in mm 7.82 7.42 20.0 max 4.8 max 6.4 max 0.5 min 3.3 1.64 1.44 Alternative 0.58 0.48 17.78 0.39 max 9.75 8.15 2.54 16 9 technical drawings according to DIN specifications 1 13015 8 Package SO16L 10.5 10.1 Dimensions in mm 9.25 8.75 2.45 2.25 2.70 2.45 0.3 0.2 0.25 0.10 0.49 0.35 7.5 7.3 1.27 10.56 10.15 8.89 technical drawings according to DIN specifications 1 14 (15) 95 11493 Rev. A3, 28-Sep-00 U4311B Ozone Depleting Substances Policy Statement It is the policy of Atmel Germany GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. Atmel Germany GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively. Atmel Germany GmbH can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. 13. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use Atmel Wireless & Microcontrollers products for any unintended or unauthorized application, the buyer shall indemnify Atmel Wireless & Microcontrollers against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. Data sheets can also be retrieved from the Internet: http://www.atmel–wm.com Atmel Germany GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 (0)7131 67 2594, Fax number: 49 (0)7131 67 2423 Rev. A3, 28-Sep-00 15 (15)