Integrated Synthesizer/Mixer Programming Guide Integrated Synthesizer/Mixer Programming Guide Covers the following products: Single mixer: RFFC2072, RFFC5072, RFFC2072A, RFFC5072A Dual mixers: RFFC2071, RFFC5071, RFFC2071A, RFFC5071A RFMD Multi-Market Products Group Integrated Synthesizer/Mixer Programming Guide REVISION HISTORY Version Date 2.0 25-Jun-12 Author(s) Eric Schonthal 1.4 Barbara Cox 1.3 1.2 1.1 1.0 0.3 0.2 0.1 0.0 Description of change(s) Added section on programming the A series devices with VCO temperature compensation. 01-Jun-11 Removed section 3, Device Setup This section appears in document titled : Integrated Synthesizer/Mixer/Modulator Family Register Map Description 18-Apr-11 Improved images in section 2. New Signals and Timing Section added 17-Mar-11 Changes to maximum frequency of operation of CT-cal circuitry. 07-Dec-10 Correction to LO Integers on Page 10 22-Oct-10 First publication 21-Oct-10 Prep for publication 29-Sep-10 Updated to allow for new spec on max VCO frequency during CT cal and for passing on to MarCom 01-Jul-10 Second Draft 29-Jun-10 Initial Draft for second revision of the chip Barbara Cox Barbara Cox Barbara Cox Robert Pipkin Robert Pipkin Chris Shepherd Chris Shepherd Chris Shepherd Integrated Synthesizer/Mixer Programming Guide CONTENTS 1. Introduction ............................................................................................................................................................................................ 4 2. Steps for Programming the device ........................................................................................................................................................ 5 2.1 Details for Setting Up Device Operation ............................................................................................................................................ 6 2.2 Details for Setting Calibration Mode ................................................................................................................................................. 7 2.3 Details for Setting Operating Frequencies ........................................................................................................................................ 8 2.3.1 Calculating Divider Values ................................................................................................................................................... 9 2.4 Details for Setting Loop Filter Calibration Mode ........................................................................................................................... 10 2.5 Details for Enabling the Device ....................................................................................................................................................... 11 3. The A Series with VCO Temperature Compensation ........................................................................................................................... 12 4. References............................................................................................................................................................................................ 13 Integrated Synthesizer/Mixer Programming Guide 1. INTRODUCTION RFMD’s second-generation integrated synthesizer/mixer RFFCxxxx series of devices (also known as Slice2) are intended to provide features similar to the first-generation RF205x series (Slice1), but with: Better phase noise VCO auto-selection General purpose outputs Higher frequency operation (in the RFFC5xxx series) Device control via the serial bus The Slice2+ devices that have an A suffix also feature advanced VCO temperature compensation. This is addressed in section 3. Figure 1. Integrated synth/mixer block diagram (dual mixer variant) Integrated Synthesizer/Mixer Programming Guide 2. STEPS FOR PROGRAMMING THE DEVICE Integrated Synthesizer/Mixer Programming Guide 2.1 DETAILS FOR SETTING UP DEVICE OPERATION Integrated Synthesizer/Mixer Programming Guide 2.2 2 DETAILS FOR SETTING CALIBRATION MODE 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 Integrated Synthesizer/Mixer Programming Guide 2.3 3 DETAILS FOR SETTING OPERATING FREQUENCIES Set operating frequencies Auto VCO select? Program VCO_AUTO.auto, P1_FREQ1.p1vcosel and P2_FREQ1.p2vcosel No If the internal auto VCO selection isn’t used the correct values must be programmed into registers Yes Auto CT_cal? Program CT_CAL1.p1ct, p1ctdef and CT_CAL2.p2ct, p2ctdef No If manual CT calibration is used the correct value must be programmed into the registers Yes Is fVCO > 3.2GHz? Program Pn_FREQ1:p1presc to 4 LF:pllcpl to 3 Yes 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 Integrated Synthesizer/Mixer Programming Guide 2.3.1 Calculating Divider Values There are three dividers on the chip controlling the local oscillator frequency: the LO divider, the N-divider, and the LO’s 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 below: 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) n_lo = INT(log2(fVCOmax / fLO) ) = 2n_lo = lo_div * fLO = 2 (fVCO < 3.2GHz) = 4 (fVCO > 3.2GHz) = fVCO / fbkdiv / fPD n = INT(n_div) nummsb = INT(216 * (n_div – n)) numlsb = INT(28 * (216*(n_div – n) - nummsb) ) lodiv fVCO fbkdiv n_div Integrated Synthesizer/Mixer Programming Guide For example an LO of 314.159265MHz with a 26MHz reference frequency would be calculated as follows: n_lo = INT(log2(5400 / 314.159265) ) = INT(log2(17.1887338736) ) = 4 = 2n_lo = 16 = lo_div * fLO = 5026.548240MHz = 4 = fVCO / 4 / fPD = 5026.54824 / 4 / 26 = 48.3321946154 n = INT(n_div) = 48 (0x030) nummsb = INT(216 * (n_div – n)) = 21770 (0x550A) numlsb = INT(28 * (216*(n_div – n) - nummsb) ) = 181 (0x85) lodiv fVCO fbkdiv n_div 2.4 DETAILS FOR SETTING LOOP FILTER CALIBRATION MODE Integrated Synthesizer/Mixer Programming Guide 2.5 DETAILS FOR ENABLING THE DEVICE 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 = fVCO / 2 / fPD = 5026.54824 / 2 / 26 = 96.66438923 n = INT(n_div) = 96 (0x060) nummsb = INT(216 * (n_div – n)) = 43541 (0xAA15) numlsb = INT(28 * (216*(n_div – n) - nummsb) ) = 106 (0x6A) n_div These new values would be programmed into the device. Since the VCO frequency is unaffected, the CT_cal value will be correct. Integrated Synthesizer/Mixer Programming Guide 3. THE A SERIES WITH VCO TEMPERATURE COMPENSATION The devices with an A suffix (RRFC2071A, RFFC2072A, RFFC5071A and RFFC5072A) all feature advanced VCO temperature compensation circuits that deliver stable synthesizer performance across the operating temperature range of -40°C to +85°C. There is no requirement to re-calibrate the VCO with changing temperature. The programming for the A devices is almost identical to the standard parts, so the programming in section 2 above applies. There are just two extra register settings that need to be written at set-up (see section 2.1) to get the best performance from the synthesizer: Set icpup = 3 in VCO_CTRL register, charge pump up enable Set ldlev = 1 in PLL_CTRL register, sets wide lock detect range There are two new registers for the VCO temperature compensation, T_VCO and T_CTRL, but these do not need to be programmed. The default settings in T_VCO and T_CTRL are required for standard operation. Please refer to the Integrated Synthesizer/Mixer Register Map and Programming Guide for further details. Note that the A devices also have some changes to the default (or reset) register settings, as follows. These do not need to be written during the device set up phase, section 2.1: 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 Integrated Synthesizer/Mixer Programming Guide 4. REFERENCES 1. RFMD company web site (http://www.rfmd.com) 2. RFMD Integrated Synthesizer and Mixer web site (http://rfmd.com/products/IntSynthMixer/) 3. Integrated Synthesizer/Mixer Evaluation Boards and Programming Tool (http://www.rfmd.com/CS/Documents/IntegratedSyntMixerEvalBoardandGUIUserGuide.pdf) 4. Integrated Synthesizer/Mixer Register Map and Programming Guide (http://www.rfmd.com/CS/Documents/IntegratedSynthMixerRegMapProgrammingGuide.pdf)