U2740B UHF AM/FM Transmitter Description The U2740B-B is an one-chip multi-purpose UHF ASK/FSK transmitter IC designed for various applications within a wide frequency range. When a Chip-Select (CS) signal is supplied, the IC starts operation (Power-up, XTO, VCO, PD) and the VCO is then locked to 128 f(XTO). The locked status is indicated at the Lock-Detect (LD) output. The digital data is supplied to either an AM- or FM-input pin, the output power being set via the AM-input pin. A differential output enables simple applications with loop antennas. An output driver (XTO_out) can be used for clocking the microcontrolller. Features Applications D One-chip solution with few external components D Wide frequency range (200 to 500 MHz) D Single voltage supply (2.2 to 5.5 V) with power-down D D D D D D D D D D feature Adjustable output power with differential output for loop antenna PLL lock-detect signal XTO output for µC clock ESD protection according to MIL–STD. 883 (except Pins 1, 2, 13 and 14) Low standby current <0.25 mA for VS = 3 V Single lithium-cell operation Keyless entry (automotive, domestic,...) Alarm systems Remote control Communication systems Ordering Information Extended Type Number U2740B-BFP Package SO16 Remarks System Block Diagram 1 Li cell U2740B Antenna VCO Encoder Keys M44Cx9x PLL Power ampl. XTO RF–Transmitter 13350 Figure 1. System block diagram TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 1 (10) Preliminary Information U2740B Pin Description OSC1 1 16 AM_in OSC2 2 15 PAGND IC 3 14 ANT2 LD 4 13 ANT1 GND 5 12 VS FM_in 6 11 CS PD_out 7 10 XTO_out XTAL2 8 9 Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 XTAL1 95 9700 Symbol OSC1 OSC2 IC LD GND FM_in PD_out XTAL2 XTAL1 XTO_out CS VS ANT1 ANT2 PAGND AM_in Function VCO tank VCO tank Internally connected Lock-detect (open collector) Ground FM modulation input Phase detector output FM modulation capacitor XTAL XTO output (open collector) Chip-select (power-up) Supply voltage Differential output 1 Differential output 2 Power amplifier ground AM modulation input Figure 2. Pinning Loop antenna VS OSC1 VS OSC2 AM_in ANT1 ANT2 f VCO PA :128 µC Power PD LD LD CS CS Data Clock PD VRef Power–up IRef FM_in XTO_out XTO XTAL1 XTAL2 GND VS PAGND 13324 Figure 3. Block diagram 2 (10) Preliminary Information TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 U2740B Circuit Description The transmitter PLL U2740B contains the complete RF part for a radio control system. The IC consists of a VCO, a complete PLL circuit, a crystal oscillator, a power amplifier and a power-up module. An integrated switch can be used to change the load capacitance of the crystal. Crystal Oscillator (XTO) It is a single-pin crystal oscillator, operating at the series resonant frequency of the crystal. Depending on the type of crystal used, this oscillator takes 3 to 20 ms until settling after setting CS to VS. The integrated switch can be used to change the load capacitance. Thus, the output frequency is FSK modulated. VCO The VCO is a voltage-controlled current source. The frequency is determined by the external LC-tank. The frequency is changed via a Varicap diode. Power Amplifier (PA) As figure 4 shows, the differential PA switches its output current between the two power output pins (ANT1, ANT2). The output current is seven times the current flowing into the AM_in Pin. The achievable output power is about 1.5 mW. PLL The complete PLL consists of a prescaler, a digital phase/frequency detector (PFD) with charge-pump output. The output frequency is locked to 128 times the frequency of the XTO. The PFD, however, operates at a frequency four times lower than that of the XTO. A lockdetect output indicates that the PLL is locked. Power-up When CS = 0 V, the circuit is in standby mode with a power–down supply current of type. IS,off = 0.1 µA. With CS = VS, the circuit is in power-up mode. VS ANT1 ANT2 0.7 V VCO Q2 Q1 0.5 mA AM_in 4.6 k 0.7 V 7 1 PAGND Iout = 3.5 mA Figure 4. Power output stage of U2740B TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 3 (10) Preliminary Information U2740B Absolute Maximum Ratings Supply voltage Voltage at Pins 13 and 14 Input current AM_in Output current lock detect Output current XTO_out Junction temperature Storage temperature Parameters Pin 12 Symbol VS Min. –0.3 –0.3 Pin 16 Pin 4 Pin 10 Tj Tstg –55 Min. Typ. Max. 5.5 10 0.75 1.5 1.5 125 125 Unit V V mA mA mA °C °C Max. 120 Unit K/W Thermal Resistance Junction ambient Parameters SO16 Symbol RthJA Operating Range All voltages are referred to GND (Pin 5) and PAGND (Pin 15), Tamb = –40 to +85_C, unless otherwise specified Parameters Supply voltage Pin 12 Supply voltage, Tamb = –20 to +85°C Minimum supply voltage, Tamb = 25°C Minimum supply voltage, Tamb = –20°C Carrier frequency Symbol VS VS Min. 2.4 2.2 200 4 (10) Preliminary Information Typ. 3.0 3.0 1.8 2.0 Max. 5.5 5.5 500 Unit V V V V MHz TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 U2740B Electrical Characteristics DC All voltages referred to GND (Pin 5), VS = 2.4 to 5.5 V, Tamb = –40 to +85°C, unless otherwise specified Parameters Supply current (p (power-down)) Test Conditions / Pins V11 = 0, I16 = 0, VS = 3 V Pin 12 V11 = 0, I16 = 0, VS = 5.5 V Pin 12 V16 = 0 V, V11 = VS Supply pp y current (power-up, transmit space) V16 = 0 V, V11 = 3 V, VS = 3 V, Tamb = 25°C, Pin 12 V16 = 0 V, V11 = 5.5 V, VS = 5.5 V, Tamb = 25°C, Pin 12 Temperature coefficient of TKI supply current 1) Supply current V16 = 3 V, V11 = 3 V, (power-up, transmit mark) VS = 3 V, Tamb = 25°C, Pin 12 Power-down voltage V16 = 0 V Pin 11 Power-up voltage V16 = 0 V Pin 11 V11 = 3 V Pin 11 Power-up p current V11 = 5.5 V Pin 11 Input current FM_in V6 = 3 V Pin 6 Output current Pin 4 Lock-detect Output current XTO_out Pin 10 Input current AM_in 2) R16 = 0 connected to Pin 16 VS = 3 V, Tamb = 25°C Tamb = 85°C Symbol Min. Typ. Max. Unit 0.05 0.25 mA 0.1 0.5 mA 5.0 8.0 mA IS, S OFF IS, ON IS, ON 4.5 5.0 6.5 mA IS, ON 4.5 5.8 7.2 mA 0.18 8 V11, OFF V11, ON 11 %/K 13.5 mA 0.4 V V 65 150 25 mA mA 1.0 40 110 16 I11, 11 ON I6 I4 1 I10 1 mA 0.60 0.65 mA mA I16 0.40 0.44 0.50 0.55 Notes: 1) There are circuit parts with increasing supply current over temperature. The resulting supply current is IS(Tamb) = ISDN (1 + (Tamb – 25°C) TKI) 2) This depends on the value of resistor R16 connected to VS. If the supply voltage is 2.0 to 3.5 V, Pin 16 can be directly connected to VS. For VS = 5 V, R16 should be 3.9 kW. TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 5 (10) Preliminary Information U2740B Electrical Characteristics AC All voltages referred to GND (Pin 5), VS = 2.2 to 5.5 V, Tamb = –40 to +85°C, unless otherwise specified Parameters Extinction ratio Output current, transmit mark, (fVCO = 433.92 MHz) 3) Output voltage swing Phase detector Output current Phase detector Output voltage swing 4) Enable settling time 5) Modulation bandwidth 6) Output frequency range XTO frequency range Modulation bandwidth Test Conditions / Pins V11 = 3 V V11 = 3 V, V16 = 0 V Pins 13 and 14 Difference, Pins 13 and 14 Pin 7 Pin 7 Pins 11, 13 and 14 Pin 6 Pins 13 and 14 Pins 9 and 10 Pin 16 Symbol 20 log (Iout,ON Iout,off) Min. Typ. –40 –50 iout,pp 2.9 3.5 4.2 mA 4 5 V v(13–14)pp Max. Unit dB IPD –1 1 mA vPDpp 0.2 VS–0.2 V Tenable BWFSK fVCO fXTO BWASK 200 1 100 50 500 6 500 ms kHz MHz MHz kHz Notes: 3) The output peak-to-peak current is 7 times the current flowing into the AM_in Pin. The driver stage of the power amplifier is designed so that the output current is switched between Pins 13 and 14. 4) The output voltage swing at each collector is limited to 2 V due to the circuit arrangement used. The output power depends on the load impedance. If optimum load impedance of 1.1 kW is used, an output power of 3.5 mA/2 sqrt(2) 1.1 kW = 1.7 mW (+2.3 dBm) results. 5) This is the time if an external clock is delivered to Pin 9 and Pin 11 is set to VS until the circuit operates. 6) FSK bandwidth is depending on values for loop filter and VCO, see application note for design hints. 6 (10) Preliminary Information TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 U2740B Application Circuit (ASK Modulation) L osc 2.2 pF I16 1 VCO 2.7 pF 2 VS 15 Loop antenna I14 f 3 14 :128 R4 R 16 16 PA I4 4 R 14 10 k Ω I13 13 V Ref IRef 5 C 10, C 11 = 4.7 pF IS VS 12 1 nF 10 nF I11 Power– up 6 11 I10 7 R 10 10 12 pF 8 XTO 9 Clock VS Lock detect Power–up µC Data 13325 Figure 5. Principle of Operation (ASK Modulation) CS (power-up) XTO_out 1/fxtal locked LD 4/fxtal AM_in (data/power) RFout Time 13326 Figure 6. TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 7 (10) Preliminary Information U2740B Application Circuit (FSK Modulation) L osc 2.2 pF I16 1 VCO 2.7 pF 2 VS R 16 16 3 15 Loop antenna I14 f 14 :128 R4 PA I4 4 R 14 10 k Ω I13 13 V Ref IRef 5 C 10, C 11 = 4.7 pF IS VS 12 1 nF 10 nF I11 Power– up 6 11 R10 I10 7 10 12 pF 8 XTO 9 39 pF Data Lock detect VS Clock Power–up µC Output power 13327 Figure 7. Principle of Operation (FSK Modulation) CS (power-up) XTO_out 1/fxtal locked LD 4/fxtal AM_in (data/power) FM_in (data) RFout Time 13328 Figure 8. 8 (10) Preliminary Information TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 U2740B Package Information Package SO16 Dimensions in mm 5.2 4.8 10.0 9.85 3.7 1.4 0.25 0.10 0.4 1.27 6.15 5.85 8.89 16 0.2 3.8 9 technical drawings according to DIN specifications 1 TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97 13036 8 9 (10) Preliminary Information U2740B 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 10 (10) Preliminary Information TELEFUNKEN Semiconductors Rev. A3, 24-Feb-97