U4222B TELEFUNKEN Semiconductors Radio Controlled Clock Receiver Description The U4222B is a bipolar integrated straight through receiver circuit for the frequency of 40 kHz. The device is designed for radio controlled clock applications, in particular for the Japanese transmitter JG2AS. Features D Stop-function available D Only a few external components necessary D Digitized serial output signal D Low power consumption D Very high sensitivity D High selectivity by quartz resonator Block Diagram VCCA 16 Power supply VCCD 9 NC 10 NC 12 TCO 13 PON 14 Driver NC 11 Comparator GND 15 AGC CAGC 4 IN2 1 Amplifier 2 Amplifier 1 IN1 2 3 GND (analog) 8 OUTA1 6 INA2 Demodulator 7 GND (digital) 5 CDEM 93 7599 e Figure 1. Rev. A1: 13.08.1996 Preliminary Information 1 (9) U4222B TELEFUNKEN Semiconductors Pin Description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Symbol IN2 IN1 GND CAGC CDEM INA2 GND OUTA1 VCCD NC NC NC TCO PON GND VCCA Function Amplifier 1 – Input 2 Amplifier 1 – Input 1 Analog ground Time constant of AGC Low pass filter Amplifier 2 input Digital ground Amplifier 1 output Supply voltage (digital) Not connected Not connected Not connected Time code output Power ON/OFF control Ground (substrate) Supply voltage (analog) VCCA IN2 1 16 IN1 2 15 GND 3 14 CAGC 4 13 TCO GND PON U4222B CDEM 5 12 NC INA2 6 11 NC GND 7 10 NC OUTA1 8 9 VCCD 94 8031 e IN1, IN2 CAGC IN2 is connected to pin 16 (VCCA). A ferrite antenna is connected between IN1 and IN2. Q of antenna circuit should be as high as possible, but the temperature influence must be compensated. The resonant resistance should be 200 kW to 300 kW for optimal sensitivity. A control voltage derived from the field strength is generated to control the amplifiers. The time constant of this automatic gain control (AGC) is influenced by the capacitor CAGC. After demodulation the signal is low pass filtered by the capacitor CDEM. OUTA1, INA2 To achieve a high selectivity, a quartz resonator is connected between the pins OUTA1 and INA2. It is used with the serial resonance frequency of the time code transmitter (e.g. 40 kHz JG2AS). The parasitic parallel capacitance C0 of the quartz resonator should be 0.5 pF to 1 pF. 2 (9) CDEM PON If PON is connected to VCCD, the U4222B receiver IC will be activated. The set-up time is typical 2.5 s after applying VCCD at this pin. If PON is connected to GND, the receiver will go into stop mode. Preliminary Information Rev. A1: 07.08.1995 U4222B TELEFUNKEN Semiconductors Condition for signal reception: S/N ≈ 4 at comparator input. TCO The digitized serial signal of the time code transmitter can be directly decoded by a microcomputer. Details about the time code format of several transmitters are described separately. The output consists of a PNP current source and a NPN switching transistor TS. The guaranteed source output current is 0.2 µA (TCO = high) and the sink current is 1 µA (TCO = low). Considering these output currents, the supply voltage and the switching levels of the following µC, the lowest load resistance is defined. The maximum load capacitance is 100 pF. In order to improve the driving capability an external pull–up resistor can be used. The value of the resistor should be 4.7 MW. To prevent an undefined output voltage in the power–down state of the U4222B, the use of this pull–up resistor is recommended. An additional improvement of the driving capability may be achieved by using a CMOS driver circuit or a NPN transistor with pull–up resistor connected to the collector (see figure 2.). Using a CMOS driver this circuit must be connected to VCCD. pin 9 VCCD 4.7 MW ISOURCE 0.2 mA 100 kW TCO TS ISINK 1 mA pin13 TCO BWA = fres/QA input noise voltage density of preamplifier: VNA1: 40 nV/Hz1/2 (typ) bandwidth of preamplifier: BWA1: 60 kHz (typ) bandwidth of crystal filter: BWCF: 16 Hz (typ) ultimate attenuation of crystal filter: DCF: –35 dB (typ) whereas: VNA k T BWA fres QA The following description gives you some additional information and hints in order to facilitate your design, in particular the problems of the antenna. Figure 3. shows the principal function of the receiver (simplified consideration). 93 7521 e Rres CF A 2 and Demodulator Comparator Figure 3. Rres: resonant resistance, A1: preamplifier, A2: amplifier 2, CF: crystal filter @ antenna noise voltage density 1.38 10–23 Ws/K (Boltzmann constant) absolute temperature bandwidth of antenna resonant frequency Q antenna Ǹ The equivalent input noise voltage at the preamplifier input is: VN Functional Description Rev. A1: 13.08.1996 VNA = (4 k T Rres)1/2 93 7689 e Figure 2. A1 Important parameters are: + ǒ @ ǸBW Ǔ ) 2 V NA CF @@@) ǒ V NA1 ǒ Ǔ Ǔ ǒ Ǔ A CF @ ǸBW ) 2 CF @ ǸBW ) @@ D 2 V NA V NA1 @ ǸBW 2 A1 D CF whereas: Rres = 300 kW, BWA = 1 kHz then VN ≈ 0.4 mV The condition for signal reception is: S/N ≈ 4 ⇒ sensitivity ≈ 1.6 mV That means that the noise voltage of antenna within the bandwidth of the crystal filter dominates and the bandwidth of antenna is uncritical for the sensitivity aspect. Preliminary Information 3 (9) U4222B TELEFUNKEN Semiconductors There is some consideration concerning the calculation of Rres: in order to achieve high signal voltage: the bandwidth BWA of the antenna circuit. As the value of the capacitor Cres in the antenna circuit is well known, it is easy to compute the resonance resistance according to the following formula: Rres should be high R res in order to achieve low antenna noise voltage: Rres should be low Rres < 200 kW: the input noise voltage of A 1 dominates Rres > 300 kW: the antenna noise voltage dominates That means the resonant resistance should be between 200 kW and 300 k Q of antenna must be high for attenuation of interfering signals. But the temperature must not influence the resonance frequency. Design Hints for the Ferrite Antenna The bar antenna is the most critical device of the complete clock receiver. But by observing some basic rf design knowledge, no problem should arise with this part. The IC requires a resonance resistance of 200 k to 300 k. This can be achieved by a variation of the L/C-relation in the antenna circuit. But it is not easy to measure such high resistances in the RF region. It is much more convenient to distinguish the bandwidth of the antenna circuit and afterwards to calculate the resonance resistance. Thus the first step in designing the antenna circuit is to measure the bandwidth. Figure 4. shows an example for the test circuit. The RF signal is coupled into the bar antenna by inductive means, e.g. a wire loop. It can be measured by a simple oscilloscope using the 10:1 probe. The input capacitance of the probe, typically about 10 pF, should be taken into consideration. By varying the frequency of the signal generator, the resonance frequency can be determined. RF - Signal generator 40 kHz Scope Probe 10 : 1 wire loop Cres 94 8049 e Figure 4. Afterwards, the two frequencies where the voltage of the RF signal at the probe drops 3 dB down can be measured. The difference between these two frequencies is called 4 (9) 1 + 2 @ @ BW @C A res whereas Rres is the resonance resistance, BWA is the measured bandwidth (in Hz) Cres is the value of the capacitor in the antenna circuit (in Farad) If high inductance values and low capacitor values are used, the additional parasitic capacitances of the coil must be considered. It may reach up to about 20 pF. The Q-value of the capacitor should be no problem if a high Q-type is used. The Q-value of the coil is more or less distinguished by the simple DC-resistance of the wire. Skin effects can be observed but do not dominate. Therefore it should be no problem to achieve the recommended values of resonance resistance. The use of thicker wire increases Q and accordingly reduces bandwidth. This is advantageous in order to improve reception in noisy areas. On the other hand, temperature compensation of the resonance frequency might become a problem if the bandwidth of the antenna circuit is low compared to the temperature variation of the resonance frequency. Of course, Q can also be reduced by a parallel resistor. Temperature compensation of the resonance frequency is a must if the clock is used at different temperatures. Please ask your dealer of bar antenna material and of capacitors for specified values of temperature coefficient. Furthermore some critical parasitics have to be considered. These are shortened loops (e.g. in the ground line of the PCB board) close to the antenna and undesired loops in the antenna circuit. Shortened loops decrease Q of the circuit. They have the same effect like conducting plates close to the antenna. To avoid undesired loops in the antenna circuit it is recommended to mount the capacitor Cres as close as possible to the antenna coil or to use a twisted wire for the antenna coil connection. This twisted line is also necessary to reduce feedback of noise from the microprocessor to the IC input. Long connection lines must be shielded. For the adjustment of the resonance frequency the capacitance of the probe and the input capacitance of the IC are to be taken into account. The alignment should be done in the final environment. The bandwidth is so low that metal parts close to the antenna influence the resonance frequency. The adjustment can be done by pushing the coil along the bar antenna. Preliminary Information Rev. A1: 07.08.1995 U4222B TELEFUNKEN Semiconductors Absolute Maximum Ratings Parameters Supply voltage Ambient temperature range Storage temperature range Junction temperature Electrostatic handling ( MIL Standard 883 C ) Symbol VCC Tamb Rstg Tj ± VESD Value 5.5 –20 to +70 –30 to +85 125 2000 Unit V _C _C _C V Symbol RthJA Value 70 Unit K/W Thermal Resistance Parameters Thermal resistance Electrical Characteristics VCCA, VCCD = 3.0 V, reference point pins 3, 7, 15, input signal according to JG2AS transmitter, Tamb = 25_C, unless otherwise specified Parameters Supply voltage range Supply current ICC = ICCA + ICCD Reception frequency Minimum input voltage Maximum input voltage Input capacitances to ground Test Conditions / Pins Pins 9, 16 Pins 9, 16 without reception signal with reception signal > 20 mV, OFF–mode Rgen = 50 W Pins 1,2 Rres 300 kW, Qres > 30 Rgen = 50 W Pins 1,2 Rres 300 kW, Qres > 30 Pins 1, 2 v v Set-up time after POWER ON TIMING CODE OUTPUT; TCO Pin 13 Output voltage RLOAD = 13 MW to GND HIGH RLOAD = 2.6 MW to LOW VCCD Output current VTCO = VCCD/2 HIGH VTCO = VCCD/2 LOW Decoding characteristics input carrier reduction 200 ms input carrier reduction 500 ms 800 ms POWER ON/OFF CONTROL; PON pin 14 Input voltage Generator output resisHIGH tance 200 kW LOW v Rev. A1: 13.08.1996 Symbol VCCA VCCD ICC Min. 2.4 fin Vin Vin Typ. 40 1.5 Max. 5.5 Unit V 40 35 0.2 mA mA mA 1.75 kHz mA 40 Cin 1 Cin 2 tpon mV 1 1 2.5 pF 5 s 0.4 V V mA mA VOH VOL VCCD-0.4 ISOURCE ISINK 0.2 1 0.4 4 t200 t500 t800 100 450 700 250 550 900 VCCD–0. 4 0.4 Preliminary Information ms ms V V 5 (9) U4222B TELEFUNKEN Semiconductors Test Circuit for JG2AS +VCC Measurement point 1 16 2 15 3 14 4 13 It must be noted: Input is shortened by 50 that means, the antenna noise is not taken into consideration. 40 kHz Generator 100 n 50 k 330 nF 100 (with variable output level) PON TCO U4222B 5 w 12 47 nF Electronic switch (Time Code) T 1s 40 kHz 6 11 7 10 8 9 VCCD–0.8 V Measuring device: Oscilloscope with high impedance probe ( 20 M) w T = 500 ms (binary “0”) or 800 ms (binary “1”) Receiver input signal calibration: Example: 2 Veff input signal ⇒ 2 2 2 103 = 5.65 mVpp at measurement point 93 7720 e Figure 5. Application Circuit for JG2AS 40 kHz +V Ferrite Antenna 1 16 2 15 3 14 4 13 CONTROL LINES CC PON 330 nF TCO MICROCOMPUTER U4222B 47 nF KEYBOARD 5 12 6 11 7 10 8 9 DISPLAY 40 kHz 94 8030 e Figure 6. 6 (9) Preliminary Information Rev. A1: 07.08.1995 U4222B TELEFUNKEN Semiconductors Information regarding Japanese Transmitter Station: JG2AS Frequency 40 kHz Transmitting power 10 kW Location: Sanwa, Ibaraki Geographical coordinates: 36_ 11’ N, 139_ 51’ E Time of transmission: permanent Time Frame 1 Minute Time Frame (index count 1 second) hours 40 45 50 55 0 5 10 P0 35 P5 30 ADD SUB ADD P4 8 4 2 1 25 80 40 20 10 P3 8 4 2 1 20 10 minutes 20 200 100 15 8 4 2 1 P2 10 8 4 2 1 P1 5 PO FRM 40 20 10 0 days code dut1 Example: 18.42 h Time Frame P0 8 40 20 10 sec. 59 0 1 2 3 4 5 4 6 1 P1 2 7 8 20 10 8 4 2 1 P2 9 10 11 12 13 14 15 16 17 18 19 20 minutes hours frame reference marker (FRM) position identifier marker P1 position identifier marker P0 0.5 second: Binary one 0.8 second: Binary zero 0.2 second: Identifier markers P0...P5 0.8 s 0.5 s 0.2 s 93 7508 e ”1” ”0” ”P” Figure 7. Modulation Time Code Format The carrier amplitude is 100% at the beginning of each second and is reduced after 500 ms (binary one) or after 800 ms (binary zero). It consists of one minute time frame. A time frame contains BCD–coded information of minutes, hours and days. In addition there are 6 position identifier markers (P0 thruP5) and one frame reference markers (FRM) with reduced carrier amplitude of 800 ms duration. Rev. A1: 13.08.1996 Preliminary Information 7 (9) U4222B TELEFUNKEN Semiconductors Ordering and Package Information Extended Type Number U4222B-CFP U4222B-CFPG1 Package SO16 plastic SO16 plastic Remarks Taping according to IEC-286-3 Dimensions in mm Package: SO16 8 (9) Preliminary Information Rev. A1: 07.08.1995 TELEFUNKEN Semiconductors U4222B Ozone Depleting Substances Policy Statement It is the policy of TEMIC TELEFUNKEN microelectronic 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. TEMIC TELEFUNKEN microelectronic GmbH semiconductor division 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. TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. 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 TEMIC products for any unintended or unauthorized application, the buyer shall indemnify TEMIC 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. TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423 Rev. A1: 13.08.1996 Preliminary Information 9 (9)