T5753C UHF ASK/FSK Transmitter DATASHEET Features ● Integrated PLL loop filter ● ESD protection also at ANT1/ANT2 (3kV HBM/150V MM; Except pin 2: 3kV HBM/100V MM) ● High output power (8.0dBm) with low supply current (9.0mA) ● Modulation scheme ASK/FSK ● FSK modulation is achieved by connecting an additional capacitor between the XTAL load capacitor and the open drain output of the modulating microcontroller ● Easy to design-in due to excellent isolation of the PLL from the PA and power supply ● Single Li-cell for power supply ● Supply voltage 2.0V to 4.0V in the temperature range of –40°C to +85°C/125°C ● Package TSSOP8L ● Single-ended antenna output with high efficient power amplifier ● CLK output for clocking the microcontroller ● One-chip solution with minimum external circuitry ● 125°C operation for tire pressure systems 4510M-RKE-09/15 1. Description The Atmel® T5753C is a PLL transmitter IC which has been developed for the demands of RF low-cost transmission systems at data rates up to 32kBaud. The transmitting frequency range is 310MHz to 350MHz. It can be used in both FSK and ASK systems. Figure 1-1. System Block Diagram UHF ASK/FSK Remote control transmitter UHF ASK/FSK Remote control receiver 1 Li cell T5753C Keys Encoder ATARx9x U3741B/ U3745B/ T5743/ T5744 XTO 4510M–RKE–09/15 IF Amp Antenna VCO LNA T5753C [DATASHEET] Control PLL Antenna 2 1 to 3 Demod PLL LNA VCO XTO Microcontroller 2. Pin Configuration Figure 2-1. Pinning TSSOP8L CLK PA_ENABLE ANT2 ANT1 Table 2-1. Pin T5753C 1 2 3 4 8 7 6 5 ENABLE GND VS XTAL Pin Description Symbol Function Configuration VS 1 CLK Clock output signal for microcontroller The clock output frequency is set by the crystal to fXTAL/4 100Ω CLK 100Ω PA_ENABLE 2 UREF = 1.1V 50kΩ Switches on power amplifier, used for PA_ENABLE ASK modulation 20μA ANT1 3 ANT2 Emitter of antenna output stage 4 ANT1 Open collector antenna output ANT2 T5753C [DATASHEET] 4510M–RKE–09/15 3 Table 2-1. Pin Pin Description (Continued) Symbol Function Configuration VS 1.5kΩ 5 XTAL VS 1.2kΩ Connection for crystal XTAL 182μA 6 VS 7 GND 8 ENABLE Supply voltage See ESD protection circuitry (see Figure 4-5 on page 8) Ground See ESD protection circuitry (see Figure 4-5 on page 8) ENABLE Enable input 200kΩ Figure 2-2. Block Diagram T5753C Power up/down f CLK ENABLE 4 1 8 f 32 PA_ENABLE GND 2 7 PDF CP ANT2 VS 3 6 LF ANT1 4 PA VCO PLL 4 T5753C [DATASHEET] 4510M–RKE–09/15 XTO 5 XTAL 3. General Description This fully integrated PLL transmitter allows particularly simple, low-cost RF miniature transmitters to be assembled. The VCO is locked to 32 fXTAL hence a 9.8438MHz crystal is needed for a 315MHz transmitter. All other PLL and VCO peripheral elements are integrated. The XTO is a series resonance oscillator so that only one capacitor together with a crystal connected in series to GND are needed as external elements. The crystal oscillator together with the PLL needs typically < 3 ms until the PLL is locked and the CLK output is stable. There is a wait time of ≥ 3ms until the CLK is used for the microcontroller and the PA is switched on. The power amplifier is an open-collector output delivering a current pulse which is nearly independent from the load impedance. The delivered output power is hence controllable via the connected load impedance. This output configuration enables a simple matching to any kind of antenna or to 50. A high power efficiency of = Pout/(IS,PA VS) of 40% for the power amplifier results when an optimized load impedance of ZLoad = (255 + j192) is used at 3V supply voltage. 4. Functional Description If ENABLE = L and the PA_ENABLE = L, the circuit is in standby mode consuming only a very small amount of current so that a lithium cell used as power supply can work for several years. With ENABLE = H the XTO, PLL and the CLK driver are switched on. If PA_ENABLE remains L only the PLL and the XTO is running and the CLK signal is delivered to the microcontroller. The VCO locks to 32 times the XTO frequency. With ENABLE = H and PA_ENABLE = H the PLL, XTO, CLK driver and the power amplifier are on. With PA_ENABLE the power amplifier can be switched on and off, which is used to perform the ASK modulation. 4.1 ASK Transmission The Atmel® T5753C is activated by ENABLE = H. PA_ENABLE must remain L for typically ≥ 3 ms, then the CLK signal can be taken to clock the microcontroller and the output power can be modulated by means of pin PA_ENABLE. After transmission PA_ENABLE is switched to L and the microcontroller switches back to internal clocking. The Atmel T5753C is switched back to standby mode with ENABLE = L. 4.2 FSK Transmission The Atmel T5753C is activated by ENABLE = H. PA_ENABLE must remain L for typically ≥ 3ms, then the CLK signal can be taken to clock the microcontroller and the power amplifier is switched on with PA_ENABLE = H. The chip is then ready for FSK modulation. The microcontroller starts to switch on and off the capacitor between the XTAL load capacitor and GND with an open-drain output port, thus changing the reference frequency of the PLL. If the switch is closed, the output frequency is lower than if the switch is open. After transmission PA_ENABLE is switched to L and the microcontroller switches back to internal clocking. The Atmel T5753C is switched back to standby mode with ENABLE = L. The accuracy of the frequency deviation with XTAL pulling method is about ±25% when the following tolerances are considered. Figure 4-1. Tolerances of Frequency Modulation VS CStray1 CStray2 LM C4 XTAL CM RS C0 Crystal equivalent circuit C5 CSwitch Using C4 = 8.2pF ±5%, C5 = 10pF ±5%, a switch port with CSwitch = 3pF ±10%, stray capacitances on each side of the crystal of CStray1 = CStray2 = 1pF ±10%, a parallel capacitance of the crystal of C0 = 3.2pF ±10% and a crystal with CM = 13fF ±10%, an FSK deviation of ±21.5kHz typical with worst case tolerances of ±16.25kHz to ±28.01kHz results. T5753C [DATASHEET] 4510M–RKE–09/15 5 4.3 CLK Output An output CLK signal is provided for a connected microcontroller, the delivered signal is CMOS compatible if the load capacitance is lower than 10pF. 4.3.1 Clock Pulse Take-over The clock of the crystal oscillator can be used for clocking the microcontroller. Atmel®’s ATARx9x has the special feature of starting with an integrated RC-oscillator to switch on the Atmel T5753C with ENABLE = H, and after 3 ms to assume the clock signal of the transmission IC, so that the message can be sent with crystal accuracy. 4.3.2 Output Matching and Power Setting The output power is set by the load impedance of the antenna. The maximum output power is achieved with a load impedance of ZLoad,opt = (255 + j192). There must be a low resistive path to VS to deliver the DC current. The delivered current pulse of the power amplifier is 9 mA and the maximum output power is delivered to a resistive load of 400 if the 1.0pF output capacitance of the power amplifier is compensated by the load impedance. An optimum load impedance of: ZLoad = 400 || j/(2 1.0pF) = (255 + j192) thus results for the maximum output power of 8dBm. The load impedance is defined as the impedance seen from the Atmel T5753C’s ANT1, ANT2 into the matching network. Do not confuse this large signal load impedance with a small signal input impedance delivered as input characteristic of RF amplifiers and measured from the application into the IC instead of from the IC into the application for a power amplifier. Less output power is achieved by lowering the real parallel part of 400 where the parallel imaginary part should be kept constant. Output power measurement can be done with the circuit of Figure 4-2. Note that the component values must be changed to compensate the individual board parasitics until the Atmel T5753C has the right load impedance ZLoad,opt = (255 + j192). Also the damping of the cable used to measure the output power must be calibrated out. Figure 4-2. Output Power Measurement at f = 315MHz VS C1 1nF L1 56nH C2 ANT1 ZLopt 3.3pF ANT2 Note: 4.4 Z = 50Ω Power meter Rin 50Ω For 345MHz C2 has to be changed to 2.7pF Application Circuit For the blocking of the supply voltage a capacitor value of C3 = 68nF/X7R is recommended (see Figure 4-3 on page 7 and Figure 4-4 on page 8). C1 and C2 are used to match the loop antenna to the power amplifier where C1 typically is 22pF/NP0 and C2 is 10.8pF/NP0 (18pF + 27pF in series); for C2 two capacitors in series should be used to achieve a better tolerance value and to have the possibility to realize the ZLoad,opt by using standard valued capacitors. C1 forms together with the pins of Atmel T5753C and the PCB board wires a series resonance loop that suppresses the 1st harmonic, hence the position of C1 on the PCB is important. Normally the best suppression is achieved when C1 is placed as close as possible to the pins ANT1 and ANT2. The loop antenna should not exceed a width of 1.5 mm, otherwise the Q-factor of the loop antenna is too high. L1 ([50nH to 100nH) can be printed on PCB. C4 should be selected that the XTO runs on the load resonance frequency of the crystal. Normally, a value of 12pF results for a 15pF load-capacitance crystal. 6 T5753C [DATASHEET] 4510M–RKE–09/15 Figure 4-3. ASK Application Circuit S1 VDD ATARx9x BPXY VS 1 S2 VSS BPXY 20 BPXY BPXY OSC1 7 T5753C Power up/down CLK ENABLE f 4 1 8 f 32 PA_ENABLE GND 2 7 PDF C3 C2 CP ANT2 VS 3 6 VS Loop Antenna LF C1 ANT1 XTAL 4 PA VCO PLL L1 XTO XTAL 5 C4 VS T5753C [DATASHEET] 4510M–RKE–09/15 7 Figure 4-4. FSK Application Circuit S1 VDD ATARx9x BPXY VS 1 S2 VSS BPXY 20 BP42/T2O BPXY 18 BPXY OSC1 7 T5753C Power up/down CLK ENABLE f 4 1 8 f 32 PA_ENABLE GND 2 7 PDF C3 CP C2 ANT2 VS 3 Loop Antenna 6 VS LF C1 C5 ANT1 XTAL 4 PA VCO XTO XTAL 5 PLL L1 C4 VS Figure 4-5. ESD Protection Circuit VS ANT1 CLK GND 8 T5753C [DATASHEET] 4510M–RKE–09/15 PA_ENABLE ANT2 XTAL ENABLE 5. Absolute Maximum Ratings Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameters Symbol Minimum Maximum Unit Supply voltage VS 5 V Power dissipation Ptot 100 mW Junction temperature Tj 150 °C Storage temperature Tstg –55 125 °C Ambient temperature Tamb –55 125 Input voltage VmaxPA_ENABLE –0.3 Note: 1. If VS + 0.3 is higher than 3.7V, the maximum voltage will be reduced to 3.7V. 6. (VS + 0.3) V Thermal Resistance Parameters Junction ambient 7. °C (1) Symbol Value Unit RthJA 170 K/W Electrical Characteristics VS = 2.0V to 4.0V, Tamb = –40°C to 125°C unless otherwise specified. Typical values are given at VS = 3.0V and Tamb = 25°C. All parameters are referred to GND (pin 7). Parameters Test Conditions Supply current Power down, VENABLE < 0.25V, –40°C to 85°C VPA-ENABLE < 0.25V, –40°C to +125°C VPA-ENABLE < 0.25V, 25°C (100% correlation tested) Symbol Min. IS_Off Typ. Max. Unit 350 7 nA µA nA < 10 Supply current Power up, PA off, VS = 3V, VENABLE > 1.7V, VPA-ENABLE < 0.25V IS 3.7 4.8 mA Supply current Power up, VS = 3.0V, VENABLE > 1.7V, VPA-ENABLE > 1.7V IS_Transmit 9 11.6 mA Output power VS = 3.0V, Tamb = 25°C, f = 315MHz, ZLoad = (255 + j192) PRef 8.0 10.5 dBm Output power variation for the full temperature range Tamb = –40°C to +85°C, VS = 3.0V VS = 2.0V PRef PRef –1.5 –4.0 dB dB Output power variation for the full temperature range Tamb = –40°C to +125°C, VS = 3.0V VS = 2.0V, POut = PRef + PRef PRef PRef –2.0 –4.5 dB dB 8.0 dBm Achievable output-power range Selectable by load impedance POut_typ Note: 1. If VS is higher than 3.6V, the maximum voltage will be reduced to 3.6V. 6.0 0 T5753C [DATASHEET] 4510M–RKE–09/15 9 7. Electrical Characteristics (Continued) VS = 2.0V to 4.0V, Tamb = –40°C to 125°C unless otherwise specified. Typical values are given at VS = 3.0V and Tamb = 25°C. All parameters are referred to GND (pin 7). Parameters Test Conditions Spurious emission fCLK = f0/128 Load capacitance at pin CLK = 10pF fO ±1 fCLK fO ±4 fCLK other spurious are lower Oscillator frequency XTO (= phase comparator frequency) fXTO = f0/32 fXTAL = resonant frequency of the XTAL, CM ≤ 10fF, load capacitance selected accordingly Tamb = –40°C to +85°C, Tamb = –40°C to +125°C Symbol Min. Typ. Max. –55 –52 Unit dBc dBc fXTO –30 –40 PLL loop bandwidth fXTAL +30 +40 250 ppm ppm kHz Phase noise of phase comparator Referred to fPC = fXT0, 25kHz distance to carrier –116 –110 dBc/Hz In loop phase noise PLL 25kHz distance to carrier –86 –80 dBc/Hz Phase noise VCO at 1MHz at 36MHz –94 –125 –90 –121 dBc/Hz dBc/Hz 350 MHz Frequency range of VCO fVCO 310 Clock output frequency (CMOS microcontroller compatible) Voltage swing at pin CLK f0/128 CLoad ≤ 10pF Series resonance R of the crystal V0h V0l VS 0.8 Rs Capacitive load at pin XT0 MHz VS 0.2 V V 110 7 pF FSK modulation frequency rate Duty cycle of the modulation signal = 50% 0 32 kHz ASK modulation frequency rate Duty cycle of the modulation signal = 50% 0 32 kHz Low level input voltage High level input voltage Input current high 0.25 ENABLE input 20 V V µA 0.25 VS(1) 5 V V µA VIl VIh IIn Note: Low level input voltage VIl VIh High level input voltage IIn Input current high 1. If VS is higher than 3.6V, the maximum voltage will be reduced to 3.6V. 10 T5753C [DATASHEET] PA_ENABLE input 4510M–RKE–09/15 1.7 1.7 Ordering Information Extended Type Number Package Remarks T5753C-6AQJ-66 TSSOP8L Note: 1. J = –40°C to +125°C + lead-free Package Information 3±0.1 3±0.1 +0.06 0.31-0.07 0.65 nom. +0.0 0.1±0.05 +0.05 0.85±0.05 Dimensions in mm 1-0.15 9. Taped and reeled, Marking: 573C, Pb-free 0.15-0.025 8. 3.8±0.3 4.9±0.1 3 x 0.65 = 1.95 nom. 8 5 technical drawings according to DIN specifications 1 4 03/15/04 TITLE Package Drawing Contact: [email protected] Package: TSSOP 8L GPC DRAWING NO. REV. 6.543-5083.01-4 2 T5753C [DATASHEET] 4510M–RKE–09/15 11 10. Revision History Please note that the following page numbers referred to in this section refer to the specific revision mentioned, not to this document. Revision No. History 4510M-RKE-09/15 Section 8 “Ordering Information” on page 11 updated 4510L-RKE-03/14 4510K-RKE-01/13 4510J-RKE-12/08 4510I-RKE-02/07 4510H-RKE-09/05 T5753 in T5753C on all pages substituted Section 8 “Ordering Information” on page 11 updated Section “Features” on page 1 changed Section 8 “Ordering Information” on page 11 updated Put datasheet in the newest template Section 4.3.1 “Clock Pulse Take-over” on page 5 updated Put datasheet in the newest template Pb-free Logo on page 1 deleted Pb-free Logo on page 1 added Put datasheet in the newest template Section 1 “Description” on page 1 updated 4510G-RKE-02/05 Figure title Figure 4-2 on page 6 updated Table “Electrical Characteristics” on pages 9 to 10 updated Table “Ordering Information” on page 11 updated Table “Absolute Maximum Ratings” (page 8): row “Input voltage” added Table “Absolute Maximum Ratings” (page 8): table note 1 added 4510F-RKE-02/05 Table “Electrical Characteristics” (page 10): row “PA_ENABLE input” updated Table “Electrical Characteristics” (page 10): table note 1 added Table “Ordering Information” (page 11): Remarks updated 12 T5753C [DATASHEET] 4510M–RKE–09/15 XXXXXX Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2015 Atmel Corporation. / Rev.: 4510M–RKE–09/15 Atmel®, Atmel logo and combinations thereof, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. 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