U4311B-FS Low-Current Superhet Remote Control Receiver Description The U4311B-FS is a monolithic integrated circuit in bipolar technology for low-current UHF remote control super-heterodyne 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 output 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 13 19 3 9 7 VRef = 2.4V 17 Monoflop Bandgap 15 Internal VRef = 2.4 V RF Level 6 Non – invert. clamping comparator Data out Wake up 10.7 MHz 12 Quadrature detector IF amplifier 5 11 16 2 Operational amplifier 18 – + 20 1 12648 log AM out FM out 10.7 MHz Data filter Figure 1. Block diagram Ordering Information Extended Type Number Package U4311B-MFSG3 SSO20 Rev. A3, 28-Sep-00 Remarks Ambient temperature up to +105°C 1 (13) U4311B-FS Pin Description OPin– OPin+ 1 20 OPout 19 VS 2 18 FMout RCwake 3 Pin Symbol Function 1 OPin+ OP amplifier non-inverted input 2 OPout OP amplifier output 3 RCwake 4 n.c. RC wake–up reset time Not connected 5 GND2 4 17 VRef 6 Compout GND2 5 16 Discr 7 RC– Comparator time constant 8 n.c. Not connected 9 RC+ Comparator time constant 10 n.c. Not connected 11 AMout 12 IFin 13 SWout Wake-up output 14 n.c. Not connected 15 GND1 Ground of the analog circuits 16 Discr FM discriminator tank 17 VRef Reference voltage 18 FMout FM discriminator output 19 VS 20 OPin– n.c. 15 GND1 Compout 6 RC– 7 14 n.c. n.c. 8 13 SWout RC+ 9 12 IFin 11 AMout n.c. 10 12649 Figure 2. Pinning Ground of the logical circuits Comparator output AM current output IF input Supply voltage OP amplifier inverted input Internal connections see figures 4 to 19 Absolute Maximum Ratings Parameters Symbol Value Unit VS 13 V Ptot 400 mW Junction temperature Tj 125 °C Storage temperature Tstg –55 to +125 °C Ambient temperature for SSO20 Tamb –40 to +105 °C Symbol Value Unit RthJA 140 K/W Supply voltage Power dissipation Tamb = 85°C Thermal Resistance Parameters Junction ambient 2 (13) SSO20 Rev. A3, 28-Sep-00 U4311B-FS 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 19 VS Quiescent supply current Pin 19 Iq 1 1.3 mA Active supply current Pin 19 Iact 2.8 3.6 mA Regulated voltage Pin 17 VRef 2.4 2.5 V Output current Pin 17 IRef 5 mA Source resistance Pin 17 RRef 5 W External capacitor Pin 17 CRef Pin 17 psrr Input resistance Pin 12 Rin Input capacitance Pin 12 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 12 and 18 f3dB 180 330 520 5 8 W pF 12 –3 dB limiting point Pin 12 VFM3dB Recovered data voltage Pin 18 VFMout FM detector output resistance Pin 18 RFMout 50 kW AMrr 25 dB 90 dBmV AM rejection ratio m = 30% Pins 12 and 18 Maximum AM input voltage Pin 12 VAMmax AM quiescent current Pin 11 IAMout Maximum AM current Pin 11 IAMoutmax 30 MHz 50 10 130 22 dBmV 230 37 mV mA mA 100 Operational amplifier Gain-bandwidth product Pins 1, 2 and 20 ft Excess phase Pins 1, 2 and 20 d Open loop gain Pins 1, 2 and 20 g0 3 6.5 80 50 ∆Vout Output voltage range Pin 2 Common mode input voltage Pins 1 and 20 Vin 0.7 Input offset voltage Pins 1 and 20 Vos –2.5 Maximum output current Pin 2 Iout Common-mode rejection ratio Pin 1 and 20 cmrr Total harmonic distortion Vin < 300 mV, f = 33 kHz, unity gain circuit Pin 2 thd Rev. A3, 28-Sep-00 4 70 degree 95 1.55 65 0 dB V 1.7 V +2.5 mV 5 mA 85 1 MHz dB 3 % 3 (13) U4311B-FS 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 > (V7 + V9) /2 (10-kW load to VRef) Pin 6 Vcout Output voltage V2 < (V7 + V9 ) /2 (10-kW load to VRef) Pin 6 Vcout 1.6 V 200 mV VRef 0 150 V 250 mV Wake-up circuit Minimum wake-up level Pin 12 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 13 ISW Output switch voltage Pin 13 VSW External wake-up resistor Pins 3 and 17 RWU External wake-up capacitor Pins 3 and 17 CWU Hold time (± 30%) th Delay time (± 30%) td 1) Measured at Pin 9, (12) 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 4 (13) 180 250 550 mA 5.5 V 2) 22 kW 10 1.5 CWU RWU CWU 0.75 kW mF s 3) s 3) Rev. A3, 28-Sep-00 U4311B-FS Circuit Description General Functions The integrated circuit U4311B-FS 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 13 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 functionally at lower IF level 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 5 6 7 8 9 10 12650 Q4 Q1 Q3 Q2 Hysteresis Op. amp. Comparator + – Comp. threshold to Pin 20 Figure 3. Principle function of the clamping comparator Rev. A3, 28-Sep-00 5 (13) U4311B-FS Internal Pin Circuitry 1251 5 12654 1 20 Figure 7. Pin 5 GND2 6 Figure 4. Pin 1 OPin+ VRef 12655 17 Figure 8. Pin 6 Compout 2 12656 17 VRef 12652 Figure 5. Pin 2 OPout 3 17 VRef 2 7 12653 Figure 6. Pin 3 RCwake 6 (13) Figure 9. Pin 7 RC– Rev. A3, 28-Sep-00 U4311B-FS 9 12660 17 VRef 13 2 12657 Figure 10. Pin 9 RC+ Figure 13. Pin 13 SWout 17 12658 VRef 15 12661 Figure 14. Pin 15 GND1 11 16 Figure 11. Pin 11 AMout 12659 12 12662 Figure 12. Pin 12 IFin Rev. A3, 28-Sep-00 Figure 15. Pin 16 Discr 7 (13) U4311B-FS 19 VS 19 12665 VRef Figure 18. Pin 19 VS 17 12666 12663 Figure 16. Pin 17 VRef 17 20 VRef 1 18 12664 Figure 17. Pin 18 FMout 8 (13) Figure 19. Pin 20 OPin– Rev. A3, 28-Sep-00 U4311B-FS 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 Data-Recovering Filter 100 dBmV Output current ( m A ) 80 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. 70 dBmV 60 40 50 dBmV 20 30 dBmV 0 6 8 10 12 14 16 IF frequency ( MHz ) 95 10332 Figure 21. IF-frequency response 0 V / Vmax ( dB ) –10 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. –20 –30 –40 0.01 95 10334 The capacitor C2 is responsible for the highpass cut-off frequency. in order to 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 cause problems. 0.1 1 10 100 Frequency ( kHz ) Figure 22. Frequency response of 2-kHz Bessel lowpass data filter Rev. A3, 28-Sep-00 9 (13) U4311B-FS 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 Wake-up out 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 C2 100 nF C3 1.5 nF C1 10 nF 12667 R1 8.2 kW R6 100 kW R12 R2 30 kW C12 C4 100 nF R5 100 kW Comparator output 100 kW 220 nF Data filter output Wake up R7 22 kW R3 220 kW R13 10 kW C5 220 nF R4 100 kW C6 220 nF 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 +85°C 70 60 –40°C 50 40 30 10 0 20 40 60 80 IF-input level ( dmBV ) Figure 24. Signal-to-noise ratio AM 10 (13) 80 20 N (high level) –80 95 10292 +25°C 100 10 95 10276 25 40 55 70 85 IF-input level (dBmV ) 100 Figure 25. AM-demodulator characteristic vs. temperature Rev. A3, 28-Sep-00 U4311B-FS VS Filter TOKO A119ACS-19000Z (L = 2.2 mH, C = 100 pF) C7 10 mF R15 22 kW R9 56 W C8 100 nF C9 10 mF R14 22 kW C10 22 pF IF input R10 300 W C11 10 nF R8 100 kW 20 19 18 17 16 15 14 13 12 Wake-up out 11 R1 8.2 kW R11 10 kW C3 1.5 nF 12668 C2 100 nF R6 100 kW 1 2 3 5 4 6 7 R12 R2 30 kW C1 10 nF 9 10 C12 C4 100 nF R5 100 kW 8 100 kW 220 nF Wake up Data filter output R7 22 k W R3 220 kW Comparator output R13 10 kW C5 220 nF R4 100 k W 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 20 95 10291 40 60 80 IF-input level ( dmBV ) 100 Figure 27. Signal-to-noise ratio FM; deviation 22.5 kHz Rev. A3, 28-Sep-00 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 11 (13) U4311B-FS Application The U4311B-FS is well-suited to implement UHF remote control or data transmission systems, based on a lowcurrent 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 the large SAW-resonator, tolerance an IF bandwidth * and in a FM system additionally the discriminator amplitude characteristic (see 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 Power supply Signal path 95 10137 Figure 29. Principle diagram of a UHF remote control receiver Package Information 5.7 5.3 4.5 4.3 Package SSO20 6.75 6.50 Dimensions in mm 1.30 0.15 0.15 0.05 0.25 6.6 6.3 0.65 5.85 20 11 technical drawings according to DIN specifications 13007 1 12 (13) 10 Rev. A3, 28-Sep-00 U4311B-FS 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. 9. 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 13 (13)