AN RFMD® REFERENCE MANUAL IQ Modulator Programming Guide Covers the following products: RFMD2080 and RFMD2081 RFMD Multi‐Market Products Group RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2011, RF Micro Devices, Inc. 120904 7628 Thorndike Road, Greensboro, NC 27409‐9421.∙For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected]. 1 of 12 IQ Modulator Programming Guide REVISION HISTORY Version Date Description of change(s) 1.0 04‐Sep‐12 Corrected instructions. Added and corrected hyperlinks. 0.1 02‐May‐11 Prep for Publication 0.0 13‐Apr‐11 Initial Draft Author(s) Barbara Cox Eric Schonthal Chris Shepherd RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 2 of 12 IQ Modulator Programming Guide CONTENTS 1. Introduction................................................................................................................................................................................... 4 2. Programming the Device ............................................................................................................................................................. 5 2.1 Set Up Device Operation .................................................................................................................................................. 6 2.2 Set Additional Features .................................................................................................................................................... 7 2.3 Set Operating Frequencies ............................................................................................................................................... 8 2.3.1 2.4 Set Loop Filter Calibration Mode .................................................................................................................................... 10 2.5 Enable Device ................................................................................................................................................................. 11 2.5.1 3. Calculating Divider Values ............................................................................................................................... 9 Optimizing Phase Noise ................................................................................................................................ 11 References .................................................................................................................................................................................. 12 RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 3 of 12 IQ Modulator Programming Guide 1. INTRODUCTION The RFMD208x series of parts are IQ modulators taking baseband quadrature signals in and directly modulating the local oscillator. RFout VddA VCO regulator dB VCO autoselect and CT-cal LO divider I DC offset control /2 Q dB Iin Baseband inputs Qin Prescaler Charge pump Refin Reference divider Phase detector Frac-N divider State machine / controller mod. Inputs and outputs GPO1 / ADD5 GPO2 / ADD6 GPO3 / FMOD GPO4 / Lock / Dout Serial interface RESETX MODE / GPO6 ENBL / GPO5 VddD SDATA SCLK ENX Figure 1. Modulator block diagram, showing the additional features of the RFMF2080 part RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 4 of 12 IQ Modulator Programming Guide 2. PROGRAMMING THE DEVICE Device off Apply power Apply power to the device . Reset device Ensure the device is set into a known and correct state . The device does include a power on reset circuit which means this operation may be omitted if the power supply is well behaved . 1 Set-up device operation 2 Set-up additional features 3 Set operating frequencies To use the device it will be necessary to program the registers with the desired contents to achieve the required operating characteristics . See following sections for details . 4 Set loop filter calibration mode 5 ENABLE device When programming is complete the device can be enabled . RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 5 of 12 IQ Modulator Programming Guide 2.1 1 SET UP DEVICE OPERATION Set up device operation P2_FREQ1:p2vcosel = 0 VCO_AUTO :ct_min = 0 VCO_AUTO:ct_max = 127 CT_CAL1:p1ctv = 12 CT_CAL2:p2ctv = 12 TEST:rgbyp = 1 Control chip with 3-wire bus? Some register settings should be changed from the default values to give best performance. If only one register set is being used it is not necessary to set the values for the other path. Yes SDI_CTRL:sipin set to 1 It is possible to control the chip via the three-wire bus or the control pins using the SDI_CTRL register. Yes SDI_CTRL:addr set to 1 It is possible to control up to four devices connected to the same programming bus by enabling MultiSlice mode Yes Set IQMOD2:attenmod and loatten Default Enable MultiSlice mode Default Set modulator gain The gain of the modulator can be set : RFMD2081: 0 to -18dB in 6dB steps RFMD2080: 0 to -38dB in 2dB steps Default Set IQMOD 2:bbatten (RFMD2080 only) Setup complete 2 RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 6 of 12 IQ Modulator Programming Guide 2.2 SET ADDITIONAL FEATURES 2 Set additional features General Purpose Outputs? Yes Program GPO:p1gpio, p2gpio and gate Up to six general purpose outputs are available on the device Yes Program GPO:lock The LOCK flag can be directed to a general purpose output if required Yes Program SDI_CTRL:4wire It is possible to set the programming bus to operate using four wires giving separate DIN and DOUT lines Program EXT_MOD:modstep, modsetup and FMOD:modulation It is possible to modulate the frequency of the VCO by programming the device or using one of the GPOs No Lock output signal? No 4-wire programming? No Frequency modulator? Yes No Additional features set 3 RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 7 of 12 IQ Modulator Programming Guide 2.3 SET OPERATING FREQUENCIES 3 Set operating frequencies Program VCO_AUTO:auto, P1_FREQ1:p1vcosel and P2_FREQ1:p2vcosel No Auto VCO select? If the internal auto VCO selection is not used the correct values must be programmed into registers Yes Program CT_CAL1:p1ct, p1ctdef and CT_CAL2:p2ct, p2ctdef No Auto CT_cal? If manual CT calibration is used the correct value must be programmed into the registers Yes Program Pn_FREQ1:p1presc to 4 LF:pllcpl to 3 Yes Is f VCO > 3.2GHz? No Program Pn_FREQ1:p1presc to 2 Program P1_FREQn:p1n, p1lodiv, p1nmsb, p1nlsb and P2_FREQn:p2n, p2lodiv, p2nmsb, p2nlsb Frequency programmed If the VCO frequency is above 3.2GHz it is necessary to set the prescaler to /4 and charge pump leakage to 3 for the CT_cal to work correctly The divider ratios must be calculated and programmed into the registers . 4 RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 8 of 12 IQ Modulator Programming Guide 2.3.1 Calculating Divider Values There are four dividers on the chip controlling the local oscillator frequency: the LO divider, the modulator divider (IQ generator), the N‐divider and its associated prescaler. The prescaler is required to restrict the input frequency to the N‐divider to a maximum frequency of 1.6GHz. This is illustrated in the simplified block diagram of the synthesizer shown below. FVCO = 2.7-5.4GHz Ch. pump Loop filter Phase det. Calibration circuits LO outputs I Q /2 IQ gen LO divider Prescaler Ndivider Ref. divider Ref input Fmax = 1.6GHz Figure 2. Simplified block diagram of the frequency synthesizer The divider values should be calculated in the following order: 1. The LO divider (lo_div) 2. The N‐divider (n, nummsb, numlsb) lodiv n_lo fVCO = INT(log2(fVCOmax / (2.fLO) ) ) = 2n_lo = 2 * lo_div * fLO fbkdiv = 2 (fVCO < 3.2GHz) = 4 (fVCO > 3.2GHz) n_div n nummsb numlsb = fVCO / fbkdiv / fPD = INT(n_div) = INT(216 * (n_div – n)) = INT(28 * (216*(n_div – n) ‐ nummsb) ) For example an LO of 314.159265MHz with a 26MHz reference frequency would be calculated as follows: n_lo = INT(log2(5600 / (2 * 314.159265) ) ) = INT(log2(8.9126768234) ) = 3 lodiv = 2n_lo = 8 = 2 * lo_div * fLO = 5026.548240MHz fVCO RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 9 of 12 IQ Modulator Programming Guide fbkdiv = 4 n_div n nummsb numlsb = fVCO / 4 / fPD = 5026.54824 / 4 / 26 = 48.3321946154 = INT(n_div) = 48 (0x030) = INT(216 * (n_div – n)) = 21770 (0x550A) = INT(28 * (216*(n_div – n) ‐ nummsb) ) = 181 (0x85) 2.4 4 SET LOOP FILTER CALIBRATION MODE Set calibration mode Enable loop filter cal? PLL_CAL1:p1kv, PLL_CAL2:p2kv set to 0 Enable the automatic VCO gain calibration if required Default Set mixer DC offsets? Default Calibration mode set Yes IQMOD3:dac = 1 Set DC offsets at mixer input to minimize LO leakage (RFMD2080 only) Set: IQMOD4:dcdaci/dcdacq IQMOD3:dcdacai /dcdacaq 5 RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 10 of 12 IQ Modulator Programming Guide 2.5 ENABLE DEVICE 5 Enable device Control pins Programming bus Select control method SDI_CTRL:sipin = 0 (default) Set SDI_CTRL:sipin = 1 Set ENBL and MODE pins Set SDI_CTRL:enbl and mode Device operational 2.5.1 Optimizing Phase Noise For optimum VCO phase noise the prescaler divider should be set to divide by 2. If the VCO frequency is greater than 3.2GHz it is necessary to set the ratio to 4 to allow the CT cal algorithm to work. After the device is enabled the divider values can be reprogrammed with the prescaler divider ratio of 2 and the new n, nummsb and numlsb values. Taking the previous example of an LO of 314.159265MHz: fbkdiv = 2 n_div n nummsb numlsb = fVCO / 2 / fPD = 5026.54824 / 2 / 26 = 96.66438923 = INT(n_div) = 96 (0x060) = INT(216 * (n_div – n)) = 43541 (0xAA15) = INT(28 * (216*(n_div – n) ‐ nummsb) ) = 106 (0x6A) These new values would be programmed into the device since the VCO frequency is unaffected the CT_cal value will be correct. RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 11 of 12 IQ Modulator Programming Guide 3. REFERENCES RFMD web site (http://www.rfmd.com) IQ Modulator web site (http://www.rfmd.com/products/IntSynthModulator/) IQ Modulator Evaluation Board and GUI User Guide (http://www.rfmd.com/CS/Documents/IntegratedSyntMixerEvalBoardandGUIUserGuide.pdf) IQ Modulator Register Map and Programming Guide (http://www.rfmd.com/CS/Documents/IntegratedSynthMixerRegMapProgrammingGuide.pdf) RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2009, RF Micro Devices, Inc. 120904 For sales or technical support, contact RFMD at (+1) 336‐678‐5570 or sales‐[email protected] or 7628 Thorndike Road, Greensboro, NC 27409‐9421 USA. Page 12 of 12