CMX017 UHF FM/FSK Transmitter D/017/3 April 1999 Advance Information Features Applications • Direct FM/FSK UHF Modulator • General Radio Link 860-965 MHz • Adjustable Modulator Output Power • General 915MHz ISM Band (USA) • Integrated Power Amplifier with Output • Spread Spectrum Wireless Systems • Fixed Frequency Transmissions Power up to +20dBm (100mW) • Low Power 2.7V Operation • Analogue/Digital Cordless Phones • Powersave and Zero-Power (<10µA) Modes • Handheld Data Terminals • 28-Pin SSOP Package • So-Ho Wireless Data Links GAIN FM/FSK MODULATOR MODOUT PAIN IPAOUT POWER AMPLIFIER DRIVER POWER AMPLIFIER MODIN PAOUT TANK BUFFERED OSCILLATOR OUTPUT OSCOUT 1.1 BANDGAP & BIAS CONTROL ENLMOD ENLPA Brief Description The CMX017 is a single chip UHF FM/FSK transmitter that combines both the RF VCO Modulator and RF Power Amplifier. It is suitable for both audio FM and digital FSK transmissions. A buffered oscillator output provides the RF signal drive to an external synthesizer or fixed frequency phase-locked loop for channel frequency selection. Modulator output power is adjustable over a 20dB range and the integrated power amplifier delivers up to +20dBm. The device also includes a powersave mode: “Transmit Standby” and a zero-power mode: “Sleep”. These allow independent power down control of both the modulator and power amplifier, thereby maximising battery life. The device can be used in conjunction with the CMX018, a double-conversion super-heterodyne receiver, to implement a complete UHF radio link. 1999 Consumer Microcircuits Limited CONTENTS Section Page 1.0 Features and Applications ............................................................................ 1 1.1 Brief Description ............................................................................................ 1 1.2 Block Diagram ................................................................................................ 3 1.3 Signal List ....................................................................................................... 4 1.4 External Components .................................................................................... 6 1.5 General Description ....................................................................................... 7 1.5.1 FM/FSK Modulator + PA Driver ..................................................... 7 1.5.2 Power Amplifier .............................................................................. 7 1.5.3 Powersave and Zero-Power Modes.............................................. 7 1.6 Application Notes........................................................................................... 8 1.6.1 Generation of the Modulated RF Signal....................................... 8 1.6.2 Powersave and Zero-Power Modes.............................................. 9 1.6.3 Lower Power Applications ............................................................ 9 1.6.4 Example Schematic and Layout ................................................... 9 1.7 Performance Specification .......................................................................... 12 1.7.1 Electrical Performance ................................................................ 12 1.7.2 Packaging ..................................................................................... 14 1.7.3 Handling Precautions .................................................................. 14 Note: As this product is still in development, it is likely that a number of changes and additions will be made to this specification. Items marked TBD or left blank will be included in later issues. Information in this data sheet should not be relied upon for final product design. 1999 Consumer Microcircuits Limited 2 D/017/3 1.2 Block Diagram Vcc3 1 28 PAIN GAIN 2 27 GND GND 3 26 MODOUT GND 4 25 GND GND 5 24 Vcc2 23 OSCOUT 22 Vcc1 21 GND 9 20 TANK GND 10 19 GND GND 11 18 MODIN Vcc4 12 17 GND ENLPA 13 16 ENLMOD 15 GND PA DRIVER PA STAGE 1 BUFFERED OSCILLATOR OUTPUT IPAOUT 6 GND 7 PA STAGE 2 GND 8 FM/FSK MODULATOR PAOUT SUBSTRATE PACKAGE GROUND PACKAGE GROUND GND 14 Figure 1 Internal Block Diagram 1999 Consumer Microcircuits Limited 3 D/017/3 1.3 Signal List Package D6 Signal Description Pin No. Name Type 1 Vcc3 POWER Power amplifier (first stage) power supply - nominally 3.0V 2 GAIN I/P Modulator output (pin 26) - Power Control 3 GND GROUND Ground-plane connection to the power amplifier 4 GND GROUND Ground-plane connection to the power amplifier 5 GND GROUND Ground-plane connection to the power amplifier 6 IPAOUT O/P Output (open-collector) from the first stage of the power amplifier 7 GND GROUND Ground-plane connection to the power amplifier 8 GND GROUND Ground-plane connection to the power amplifier 9 PAOUT O/P Output (open-collector) from the second stage of the power amplifier 10 GND GROUND Ground-plane connection to the power amplifier 11 GND GROUND Ground-plane connection to the power amplifier 12 Vcc4 POWER 13 ENLPA CMOS I/P Power Amplifier powersave logic control. A logic '0' powers down the Power Amplifier and Driver stages 14 GND GROUND Ground-plane connection 15 GND GROUND Ground-plane connection 16 ENLMOD CMOS I/P Modulator zero-power logic control. A logic '0' powers down the Modulator and Buffered Oscillator stages 17 GND GROUND Ground-plane connection 18 MODIN I/P 19 GND GROUND 20 TANK I/P 1999 Consumer Microcircuits Limited Power amplifier (second stage) power supply - nominally 3.0V Baseband modulation input signal Ground-plane connection to the VCO VCO Tank circuit/Resonator connection 4 D/017/3 Package D6 Signal Description Pin No. Name Type 21 GND GROUND 22 Vcc1 POWER Modulator power supply - nominally 3.0V 23 OSCOUT O/P Buffered Oscillator (open-collector) output 24 Vcc2 POWER 25 GND GROUND 26 MODOUT O/P 27 GND GROUND 28 PAIN I/P Notes: I/P = O/P = Ground-plane connection to the modulator and VCO buffer Power Amplifier Driver power supply - nominally 3.0V Ground-plane connection for the Power Amplifier Driver Modulator output Ground-plane connection for the Power Amplifier Driver Power Amplifier input Input Output 1999 Consumer Microcircuits Limited 5 D/017/3 1.4 External Components Component Values: L1 L2 L3 L4 D1 ~ C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 R1 R2 R3 R4 1.5nH 22nH 6.8nH 22nH Varactor Resonator 5.6pF 33pF 4.3pF 6.8pF 100pF 100pF 100pF 100pF 100pF 100pF 100pF 100pF 10kΩ 10kΩ TBD kΩ TBD kΩ Varactor Diode, type SMV1233-011 Co-Axial Resonator, type RG402, length = 11mm, shorted end. (value is application dependent) SMD Potentiometer (value is application dependent) NOTE: Components are surface mount, type SMD0603, unless otherwise marked. Figure 2 Example of CMX017 with External Components 1999 Consumer Microcircuits Limited 6 D/017/3 1.5 General Description The CMX017 is a single chip UHF FM/FSK transmitter that combines both the RF VCO Modulator and RF Power Amplifier. It is suitable for both audio FM and digital FSK transmissions. A buffered oscillator output provides the RF signal drive to an external synthesizer or fixed frequency phase-locked loop for channel frequency selection. Modulator output power is adjustable over a 20dB range and the integrated power amplifier delivers up to +20dBm. The device also includes a powersave mode: “Transmit Standby” and a zero-power mode: “Sleep”. These allow independent power down control of both the modulator and power amplifier, thereby maximising battery life. The device can be used in conjunction with the CMX018, a double-conversion super-heterodyne receiver, to implement a complete UHF radio link. 1.5.1 FM/FSK Modulator + PA Driver The modulator circuit uses an integrated oscillator whose frequency can be directly modulated by the DC-coupled input base-band signal, at the MODIN pin, to generate a frequency modulated (FM or FSK) RF signal. The oscillator requires an external varactor and resonator circuit, connected at the TANK pin, to tune to the required RF channel. A buffered oscillator signal is provided from an opencollector output, at the OSCOUT pin, to drive an external frequency synthesizer for the channel selection. The output power, at the MODOUT pin, is variable over a 20dB range. The output power is maximum when the GAIN pin is connected to Vcc and is reduced by typically 20dB when this pin is connected to 0V. The output impedance at the MODOUT pin is typically 50Ω. 1.5.2 Power Amplifier (PA) The power amplifier has two internal stages, each biased for class-B operation, and is designed to have a fixed overall power gain. The input and output impedances can be terminated with 50Ω. A typical power gain improvement of 2dB is achieved using simple external matching networks. 1.5.3 Powersave and Zero-Power Modes The Modulator and Buffered Oscillator stages are powered down independently of the PA Driver and Power Amplifier stages, by means of the ENLMOD and ENLPA logic inputs: A logic '0' at ENLMOD powers down the Modulator and Buffered Oscillator stages. A logic '0' at ENLPA powers down the PA Driver and Power Amplifier stages. Refer to the block diagram in Figure 1 and to the Applications Section 1.6.2. 1999 Consumer Microcircuits Limited 7 D/017/3 1.6 Application Notes 1.6.1 Generation of the Modulated RF Signal The modulator on the CMX017 relies on the direct modulation of the RF Voltage Controlled Oscillator (VCO), which is stabilised to the channel centre frequency by an external Frequency Synthesizer or Phase Locked Loop (PLL). The user has control over the external PLL filter and VCO tank components and choice of these components will have an impact upon the following PLL parameters: Closed loop bandwidth, settling time and transient response Modulation linearity VCO phase noise Three modulation requirements may be achieved as follows: a) The minimum modulation signal frequency is above the PLL Closed Loop Bandwidth In applications where the transmit channel frequency is fixed or occasionally changed, a narrow PLL bandwidth can be chosen such that the minimum modulation frequency is in excess of the PLL bandwidth. With the PLL active whilst the base-band signal is applied to the modulator there will be negligible distortion of the modulated RF output signal. A benefit of this technique is that an output phase noise improvement is achieved, compared to the free running VCO phase noise characteristic. b) The minimum modulation signal frequency is within the PLL Closed Loop Bandwidth In Frequency Hopped Spread Spectrum applications the frequency synthesizer must be agile. Consequently the PLL bandwidth should be designed to achieve the required hop rate and, in most systems, this bandwidth will exceed the minimum modulation frequency. With the PLL active during modulation, the loop will compensate for the signal frequency components within the loop bandwidth, introducing a frequency dependant distortion of the modulated RF output signal. To avoid the modulation distortion the carrier frequency is tuned by the external synthesizer chip, with no modulating signal applied. The synthesizer control is then disabled, by setting the charge-pump output of the synthesizer to tri-state. The DC coupled baseband signal, applied to the MODIN pin, then modulates the free running VCO to generate the FM or FSK output signal. c) A flat modulator response is required down to DC, whilst benefiting from the phase noise improvements due to the PLL (Two-Point Modulation) Unlike in the above two cases, where a fixed reference frequency is used in the PLL, the Two-Point Modulation technique requires modulation inputs to both the PLL reference oscillator and to the RF VCO circuits. The modulation signal should be applied to both modulation inputs with suitable AC/DC levels and with the correct phase to achieve cancellation of the loop’s feedback. This prevents the radio’s PLL circuitry from counteracting the modulation process and so provides a clean flat modulation response down to DC. 1999 Consumer Microcircuits Limited 8 D/017/3 1.6.2 Powersave and Zero-Power Modes It is possible to power down each section of the transmitter independently. This feature may be useful when the CMX017 is configured, with the CMX018, as a radio transceiver. It allows the transmitter to be powered on and off, thereby saving power, during the sleep and standby periods. In SLEEP mode (ENLMOD = '0' and ENLPA = '0') all sections of the device are powered down and the current consumption is reduced to less than 10µA. This is the zero-power mode. In TRANSMIT-STANDBY mode (ENLMOD = '1' and ENLPA = '0') only the PA Driver and Power Amplifier stages are powered down, whilst the Modulator and Buffered Oscillator remain active. This powersave mode allows the external frequency synthesizer to stabilise the channel centre -frequency prior to the RF transmission. In TRANSMIT mode (ENLMOD = '1' and ENLPA = '1') both the Modulator and Power Amplifier sections of the device are fully operational. Note: The device can be used as a stand alone “UHF Power Amplifier” by forcing (ENLMOD = '0' and ENLPA = '1'). The efficiency is maximised by connecting the Vcc2 pin to 0V. (The Vcc1 pin must remain connected to 3.0V.) 1.6.3 Lower Output Power Applications For very short range applications the antenna drive can be taken from the modulator output, MODOUT, at pin 26. The Power Amplifier is powered down by connecting Vcc3 and Vcc4 (pins 1 and 12) to 0V. This allows the supply current to be minimised and the Modulator output to be enabled or disabled using the ENLPA input at pin 13. 1.6.4 Example Schematic and Layout The following schematic (Figure 3) and printed circuit layout (Figure 4) show a typical application interface for the CMX017. To aid legibility, the schematic and layout are available electronically from the CML website http://www.cmlmicro.co.uk or on floppy disk by request from CML's office. Alternative components and component values are shown on the schematic. These should be selected according to the intended application. The schematic uses the following ICs: U2 U4 IC Works WB1315X Analog Devices AD8532-SO8 1999 Consumer Microcircuits Limited 9 D/017/3 Figure 3 Application Schematic 1999 Consumer Microcircuits Limited 10 D/017/3 1uF C43 C48 3V C40 100pF 100pF 15uH L9 100uF C45 100pF J2 C39 C41 C56 100 R100 100pF 3V 18 17 100uF C57 100nF C58 TFMCON20M 20 16 15 19 14 12 10 8 13 11 9 6 4 3 J1 2 7 C12 10nF 5V 100pF C46 100pF C145 C16 N/C 100pF C44 100pF 100pF 12pF 1 5 C5 100uF C19 C65 C4 33pF 100nH L1 100pF 100pF C42 22nH L5 C10 100pF L4 1nF C38 C31 C15 FIN1 GND DO1 VP1 VCC1 GND ENLPA VCC4 GND10 GND9 PAOUT GND8 GND7 IPAOUT GND6 GND5 GND4 GAIN VCC3 10 9 8 7 U2 R21 GND3 PAIN 15 16 17 18 19 20 21 22 23 24 25 26 27 28 C34 R14 10K 16 17 18 19 20 100k R22 CLOCK DATA LE GND R23 100k 11 12 13 14 FIN2B 15 FIN2 GND DO2 VP2 VCC2 100k 100pF C37 100nF 100pF 2.2uF C33 GND ENLMOD GND MODIN OSCGND TANK GND1 VCC1 OSCOUT VCC2 GND2 MODOUT C32 15uH WB1315X L8 5V CMX017D6 U1 SYNT_CLK SYNT_DATA SYNT_STB FO_LD GND OSC_IN GND 6 FIN1B 5 4 3 2 1 14 13 12 11 10 9 8 7 6 5 4 3 2 1 100pF 100pF 1.5nH C3 C1 C22 33pF C2 L2 C7 6.8nH N/C 20nH L6 3V 100pF C26 100pF 100pF C11 100pF 5.6pF C18 100pF 4.7pF C13 100nF C6 L3 100nH 3V 1 GND IN 2 TXRESNR C14 6.8pF 47k 470nF C35 R17 N/C 5V D1 3pF R1 C36 100nF 1k R19 2 4 - + U4 5 6 10nF 0R R18 ( 7 - N/C) 1 R2 100R AD8532-SO8 2.2uF 3 47k 1nF C24 C9 C27 8 0R R9 N/C 10k R13 N/C 15uH L7 C8 Figure 4a Application Layout - Top Copper Figure 4b Application Layout - Bottom Copper (not reversed) Available from http://www.cmlmicro.co.uk 1999 Consumer Microcircuits Limited 11 D/017/3 1.7 Performance Specification 1.7.1 Electrical Performance Absolute Maximum Ratings Exceeding these maximum ratings can result in damage to the device. Supply (Vcc) Input Voltage Power Amplifier Input Power Pin 1, 12, 22, 24 2, 13, 16, 18, 20 28 D6 Package Total Allowable Power Dissipation at Tamb = 25°C ... Derating Storage Temperature Min. -0.3 -0.3 Max. 7.0 Vcc + 0.3 +7 Units V V dBm Min. Max. 1100 11 +125 Units mW mW/°C °C Max. 3.3 965 +60 Units V MHz °C -55 Operating Limits Correct operation of the device outside these limits is not implied. Notes Supply (Vcc) Operating Frequency Range Operating Temperature 1999 Consumer Microcircuits Limited 12 Min. 2.7 860 -10 D/017/3 Operating Characteristics For the following conditions unless otherwise specified: Vcc = 2.7V to 3.3V, Tamb = -10°C to +60°C, RF = 915MHz, 50Ω source and load impedance. Min. Typ. Max. Units DC Parameters Device Fully Enabled (ENLPA=HI and ENLMOD=HI) Icc1 [Output Power = +20dBm at PAOUT (Pin 9)] Icc1 [Output Power = +10dBm at PAOUT (Pin 9)] Icc1 [Output Power = 0dBm at PAOUT (Pin 9)] Pin - 130 60 40 - mA mA mA Device in Power-Down Modes Icc1 in STANDBY mode (ENLPA = LO and ENLMOD = HI) Icc1 in SLEEP mode (ENLPA = LO and ENLMOD = LO) - 24 TBD 10 mA µA 26 26 26 19 26 26 18 26 18 26 - -4.0 -9.0 -14 -10 -25 -35 0.4 1.5 TBD TBD - dBm dBm dBm dBm dBc dBc MHz/V MHz kBits/S 28, 9 28, 9 28, 9 28,9 9 9 9, 28 9 - 22 24 2.0 1.5 +1.0 0 -35 TBD - dB dB dB dB dBm dBm dB AC Parameters Modulator, VCO Buffer and PA Driver Output Power [GAIN (pin 2) at Vcc] Output Power [GAIN (pin 2) at 1.5V] Output Power [GAIN (pin 2) at 1.0V] 2 Buffered VCO Output at OSCOUT pin 3 Oscillator Second Harmonic Output 3 Oscillator Third Harmonic Output 4 Modulation Sensitivity 5 Maximum Deviation Input Data Rate Output VSWR (at maximum output power) Power Amplifier Power Gain Power Gain (with external matching at Vcc = 3.3V) 6 Maximum Power Gain Variation 6 Maximum Power Gain Variation (with matching) Input 1dB Compression Point Input 1dB Compression Point (with matching) Reverse Isolation Output VSWR (at maximum output power) Notes: 1. 2. 3. 4. 5. 6. Total current from the external 3.0V power supply. Power measured into a 50Ω load. With external matching. Stepped modulation voltage input from 1.0V to 2.0V. Stepped modulation voltage from 0V to 3.0V. Input Power = -15dBm to -1dBm. 1999 Consumer Microcircuits Limited 13 D/017/3 UHF FM/FSK Transmitter 1.7.2 CMX017 Packaging Figure 5 28-Pin Plastic SSOP Mechanical Outline: Order as part no. CMX017D6 1.7.3 Handling Precautions This device is a high performance RF integrated circuit and is ESD sensitive. Adequate precautions must be taken during handling and assembly of this device. CML does not assume any responsibility for the use of any circuitry described. No IPR or circuit patent licences are implied. CML reserves the right at any time without notice to change the said circuitry and this product specification. CML has a policy of testing every product shipped using calibrated test equipment to ensure compliance with this product specification. Specific testing of all circuit parameters is not necessarily performed. 1 WHEATON ROAD WITHAM - ESSEX CM8 3TD - ENGLAND Telephone: +44 1376 513833 Telefax: +44 1376 518247 e-mail: [email protected] http://www.cmlmicro.co.uk