HMC703LP4E Datasheet, PDF (19/58 Pages) Hittite Microwave Corporation – 8 GHZ FRACTIONAL SYNTHESIZER

v02.0813
HMC703LP4E
8 GHz fractional synthesizer
Required CP Offset = (2.5 ∙ 10-9+ 4T_PS) ∙ (F_comparison) ∙ I_CP where:
T_PS: is the RF period at the fractional prescaler input
I_CP: is the full scale current setting of the switching charge pump
(EQ 4)
Note that this calculation can be performed for the center frequency of the VCO, and does not need refinement for small
differences (<25%) in center frequencies. Also, operation with unreasonably large charge pump offset may cause Lock
Detect to incorrectly indicate an unlocked condition. To correct, reduce the offset to recommended levels.
Another factor in Fractional spectral performance is the choice of the Delta-Sigma Modulator mode. Mode B is normally
recommended, as it allows higher PD frequencies and makes it easier to filter the fractional quantization noise. For low
prescaler frequencies (<1.5GHz), however, mode A can offer better in-band spectral performance. See Reg 06h[0] for
DSM mode selection. Finally, all fractional synthesizers cre­ate fractional spurs at some level. Hittite offers the lowest
level fractional spurious in the indus­try in an integrated solution.
Operational Modes
The HMC703LP4E can operate in a eight of different modes (Reg 06h[7:5]), and supports “Triggering” from 3 different
sources. The modes of operation include:
“Integer Mode”
“Fractional Mode”
“Exact Frequency Mode”
Frequency Modulation “FM Mode”
Phase Modulation “PM Mode”
“Frequency Sweep Mode” (3 types)
All modes require Fractional mode to be enabled except for Integer mode. Fractional mode allows fine frequency
steps. Exact Frequency mode allows precise fractional frequency steps with zero frequency error. FM and PM modes
can be used for simple communications links, with data rate limitations set by the loop filter bandwidth. The PM mode
also allows for precise incremental phase adjustments, which can be important in phased arrays and other systems.
Frequency sweep supports built-in one-way, two-way, or user defined frequency sweeps, useful in FMCW radar
applications.
Depending on the mode, the auxiliary registers Reg 0Ah, Reg 0Ch and Reg 0Dh are used for different functions, as
shown in Table 6.
6 - 19
F^Irrliniecgo^fseohpr_ntrsomsp_enoasftir_isibtoi_hic^ngilrirtde_yafunpi,^rstnaed_airdstsihee_sbesuyl^dmti_hiv_mebae_dtypmlbr_iAcyay_anyAta9ioa_rlnoen7agsn_luoo8dlDrgt-^eofDr₂^vt_toheio_m5^ceveri_0cwisp_tesi-ssil_use3afsobeuc3_r.neie4_dtSliseep3^vuro_eescader_inf,d_iyc•^tnoae_optriabr_oftens_oe9srn:^a_7tascnH_ou8^cyrbui_j-ipernt2^aacft_rttti^e_5ient_tnoe_g0^atecnr_-mhdiM_g3aehnrn3tei_gstc^lsei₇^aor_{obwf3oflAiept}w_{hn.faoaatHuel}a_otoxngv^wntsoe_{Deotviecr•}^evC_eori,.ctheo_NnesOoor_r. prod^FOPre^ohna^r_roet_npiO_To_erei:nn^cc7e,-_h8,ln2_1inod-3leEe_o2lgil_9via_yz^e-_t4a^rWy7_wb^,a0ye^a_w0,nt_•Pwh^d.OO_.^tDh^or.d_irBeptitov_rli^axet_ocen9,^e_.l1iCc_n0oeo6rh^d,_mae^eNtl^rwom^s:rwws^Awofⁿo_o.aadr^lnd^o,agM,_loM_ADge.0A_cv2oic0m0^e61^s2,8_-9I2ⁿ¹4_0c.6,
Trademarks and registered trademarks are the property of their_Ares_pp_pec_lt_iiv_ce_aow_tin_oer_ns. _{Support: [e-mail] m}Support: Phone: 1-800-ANALOG-D