Preliminary Data Sheet CME6005 C-MAX RC Receiver IC RF Technology Specialist CME6005 Single and dual band receiver IC 1 Short Description The CME6005 is a BiCMOS integrated straight through receiver with build in very high sensitivity for the time signal transmitted from WWVB, DCF77, JJY, MSF and HBG. The receiver is prepared for single-and dual band (by using additional capacitor matching pin) reception. Integrated functions as stand by mode, complementary output stages and hold mode function offer features for universal applications. The power down mode increases the battery lifetime significantly and makes the device ideal for all kinds of radio controlled time pieces. 2 Features o Low power consumption (<100µA) o Only a few external components necessary o Very high sensitivity (0.4µV) o AGC hold mode o Dedicated input for external crystal o Wide frequency range (40 ... 120 kHz) capacitance matching for dual band o Low power applications (1.2 .. 5.0 V) application o Improved noise resistance o High selectivity by using crystal filter o Integrated AGC adaptation o Power down mode Benefits o Dual band application o Existing software can be used o Extended battery operating time QOUT QC QIN DEM Block Diagram TCO IN 2 IN 1 + - TCON PEAK AGC DET. BIAS PON VCC GND PK HLD Figure 1. Block diagram SPEC No. Revision State C-MAX printed Version Page CME6005 A7 07.12.04 07.12.2004 English 1 of 15 Preliminary Data Sheet CME6005 C-MAX 3 Ordering Information Extended Type Number Package Remarks CME6005-DDT no die in trays CME6005-TCSH yes SSO16 CME6005-TCQH Yes SSO16 Taped and reeled *The packaged version of CME6005 complies with lead free JEDEC standard J-STD 020B. 4 Absolute Maximum Ratings Parameters Symbol Value Unit Supply voltage VCC 5.5 V Ambient temperature range T -40 to +85 °C amb Storage temperature range R -55 to +150 °C stg Junction temperature T 125 °C j Electrostatic handling (MIL Standard 883 D HBM) +/- V +/-4000 V ESD Electrostatic handling (MIL MM) +/- V +/-400 V ESD 5 PAD Coordinates The CME6005 is available as die for "chip-on-board" mounting and in SSO16 package. DIE size: 1,42mm x 1,63 mm PAD size: 100 x 100 µm (contact window 84µm / 84µm) Thickness: 300µm±10µm Symbol Function x-axis (µm) y-axis (µm) Pad # (dice) Pin # (SSO16*) QIN Crystal Input 118,5 1138,2 1 2 GND Ground 118,5 969,6 2 3 QOUT Crystal output 118,5 803,3 3 4 VCC Supply voltage 118,5 464,8 4 5 IN2 Antenna input 2 118,5 304,8 5 6 IN1 Antenna input 1 118,5 99,6 6 7 TCON Negative signal output 1039,5 87,6 7 10 TCO Positive signal output 1167,8 471,3 8 11 PON Power ON input 1167,8 738,4 9 12 PK Capacity for AGC 1167,8 924,3 10 13 HLD AGC hold 1167,8 1141,5 11 14 DEM Demodulator output 1167,8 1326,4 12 15 QC Crystal matching Cap 118,5 1319,1 13 1 Coordinate requirements should be achieved SPEC No. Revision State C-MAX printed Version Page CME6005 A.7 07.12.04 07.12.2004 English 2 of 16 Preliminary Data Sheet CME6005 C-MAX 6- Pad Layout Pin Layout SSO16 1 16 NC QC 12 DEM QC 13 2 15 QIN DEM QIN 1 11 HLD 3 14 GND HLD 2 GND 10 PK 4 13 QOUT PK 3 QOUT CME6005 9 PON FB The PAD coordinates 5 12 VCC PON are referred to the left 8 TCO VCC 4 bottom point of the contact 6 11 IN 2 TCO window 5 IN 2 7 10 IN 1 TCON 6 IN 1 7 TCON 89 NC NC Y-axis X-axis Reference point (%) Figure 2. Pad layout Figure 3. Pin layout SSO16 PIN Description IN1, IN2 A ferrite antenna is connected between IN 1 and IN 2. For high sensitivity, the Q factor of the antenna circuit should be as high as possible. Please note that a high Q factor requires temperature compensation of the resonant frequency in most cases. We recommend a Q factor between 40 and 150, depending on the application. An optimal signal-to-noise ratio will be achieved by a resonator resistance of 40 kΩ to 100 kΩ. QOUT, QIN , QC In order to achieve a high selectivity, a crystal is connected between the Pins QOUT and QIN. It is used with the serial resonant frequency according to the time-code transmitter and acts as a serial resonator. Up to 2 crystals can be connected parallel between QOUT and QIN. For one crystal, the given parallel capacitor of the filter crystal (about 1.4 pF) is internally compensated so that the bandwidth of the filter is about 10 Hz. For two crystals, an additional external capacitor with the value of about 1.4 pF has to be connected parallel between QC and QIN. The impedance of QIN is high. Parasitic loads have to be avoided. DEM Demodulator output. To ensure the function, an external capacitor has to be connected at this output. HLD AGC hold mode: HLD high (V = V ) sets normal function, HLD low (V = 0) holds for a short time the HLD CC HLD AGC voltage. This can be used to prevent the AGC from peak voltages, created by e.g. a stepper motor PK Peak detector output. An external capacitor has to be connected to ensure the function of the AGC regulation. The value of the capacitance influences the AGC regulation time. NOTE: To realize a good regulation timing of the demodulator and the peak detector the value of the capacitors at DEM and PK have to be changed for the different protocols. SPEC No. Revision State C-MAX printed Version Page CME6005 A.7 07.12.04 07.12.2004 English 3 of 16 Preliminary Data Sheet CME6005 C-MAX VCC, GND V and GND are the supply voltage inputs. The positive supplies have to be connected externally, and also CC the ground pins. To power down the circuitry it is recommended to use the PON input and not to switch the power supply. Switching the power supply results in a long power up waiting time. PON If PON is connected to GND, the receiver will be activated. The setup time is typically 0.5 sec after applying GND to this pin. If PON is connected to VCC, the receiver will switch to Power Down mode. TCO, TCON The serial signal of the time-code transmitter can be directly decoded by a micro controller. Details about the time-code format of several transmitters are described separately. If TCO is connected, TCON must be open or counterwise. SPEC No. Revision State C-MAX printed Version Page CME6005 A.7 07.12.04 07.12.2004 English 4 of 16 Preliminary Data Sheet CME6005 C-MAX 7 Design Hints for the Ferrite Antenna 7.1 Dimensioning of antenna circuit for different clock/watch applications The bar antenna is a very critical device of the complete clock receiver. Observing some basic RF design rules helps to avoid possible problems. The IC requires a resonant resistance of 40 kΩ to 100 kΩ. This can be achieved by a variation of the L/C-relation in the antenna circuit. In order to achieve this resonant resistance, we recommend to use antenna capacitors of a value between 2.2nF and 6.8nF. The optimum value of the capacitor has to be specified respecting the concrete application needs and different boundary conditions(ferrite material, type of antenna wire, available space for antenna coil).It is not easy to measure such high resistances in the RF region. A more convenient way is to distinguish between the different bandwidths of the antenna circuit and to calculate the resonant resistance afterwards. Thus, the first step in designing the antenna circuit is to measure the bandwidth. Figure 12 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 time signal generator, the resonant frequency can be determined. Time signal Scope generator Probe 10:1 Wire loop C res Figure 12. At the point where the voltage of the RF signal at the probe drops by 3 dB, the two frequencies can then be measured. The difference between these two frequencies is called the bandwidth BW of the antenna circuit. A As the value of the capacitor C in the antenna circuit is known, it is easy to compute the resonant res resistance according to the following formula: 1 R = res 2 x π X BW X C A res Where R is the resonant resistance, res BW is the measured bandwidth A C is the value of the capacitor in the antenna circuit (Farad). res If high inductance values and low capacitor values are used, the additional parasitic capacitance of the coil must be considered. The Q value of the capacitor should be no problem if a high Q type is used. The Q value of the coil differs more or less from the DC resistance of the wire. Skin effects can be observed but do not dominate. Therefore, it should not be a problem to achieve the recommended values of the resonant resistance. The use of thicker wire increases the Q value and accordingly reduces bandwidth. This is advantageous in order to improve reception in noisy areas. On the other hand temperature compensation of the resonant frequency might become a problem if the bandwidth of the antenna circuit is low compared to the temperature variation of the resonant frequency. Of course, the Q value can also be reduced by a parallel resistor. Temperature compensation of the resonant frequency is a must if the clock is used at different temperatures. Please ask your supplier of bar antenna material and of capacitors for specified values of the temperature coefficient. SPEC No. Revision State C-MAX printed Version Page CME6005 A.7 07.12.04 07.12.2004 English 5 of 16 Preliminary Data Sheet CME6005 C-MAX 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 the Q value 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 C as close as res 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. A final adjustment of the time-code receiver can be carried out by pushing the coil along the bar antenna. 7.2 Dimensioning of capacitor C DEM The value of 22nF for capacitor C as shown in chapter 9 and 10 represents the minimum value for DEM frequency of 77.5 kHz. For lower frequencies (40kHz, 60kHz) a minimum value of C =47nF should be DEM used. For a better damping of noise and other interference it is recommended to double the values of C ,. DEM That means C = 47nF for 77.5kHz and C = 100nF for 40kHz and 60kHz. This optimization has to be DEM DEM done according to each application. SPEC No. Revision State C-MAX printed Version Page CME6005 A.7 07.12.04 07.12.2004 English 6 of 16 Preliminary Data Sheet CME6005 C-MAX 8 Electrical Characteristics V = 3V, input signal frequency 77.5 kHz +/- 5 Hz; carrier voltage 100% reduction to 25% for t = 200ms; MOD CC t = 25°C, max./min. limits are at +25...C ambient temperature, unless otherwise specified. amb Parameter Test condition / Pin Symbol Min. Typ. Max. Unit Supply voltage range Pad/Pin V V 1.2 5.5 V CC CC Supply current Pad/Pin V I <90 100 µA CC CC Set-up time after V ON V = 3V 1.5 s t CC CC Reception frequency range F 40 120 kHz in Minimum input voltage Pad/Pin IN1, IN2 0.4 0.6 µV V in Maximum input voltage Pad/Pin IN1, IN2 V 30 50 mV in Input amplifier max. gain V 47 dB U1 (V = 0.2V) PK Input amplifier min. gain -40 dB V U2 (V = 0.8V) PK Pins TCO, TCON 0.1 x V Output low lol = 10µA CC V 0.9 x Vcc Output high loh = -10µA V Power-ON control; PON Pad/Pin PON Input level Low level 0.15 V V cc High level 0.85 V V cc 0.1 Input leakage current 0