HMC701LP6CE Datasheet, PDF (45/46 Pages) Hittite Microwave Corporation – 8 GHz 16-Bit Fractional-N Synthesizer

v03.0709
HMC701LP6CE
8 GHz 16-Bit Fractional-N Synthesizer
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Table 38. Reg 1Ch Phase Detector CSP Register
Bit
Type
Name
Default
3:0
R/W pfds_sat_deltaN
5’d4
4
R/W pfds_rstb_force
0
5
R/W pfds_rstb
1
Description
0= Cycle Slip Prevention (CSP) disabled
4-bit value to advance or retard phase detector in
VCO cycles if it reaches 2pi , i.e. cycle slip
prevention. 1st bit is polarity, enabled by rstb
CSP PFD Flip-flops RSTB:
1 - controlled by the pfds_rstb bit:
0 - auto-controlled by the CSP logic
Forces the PFD into reset, which tristates charge
pump, freezes charge on the loop filter, and
hence opens the loop
CSP PFD FF rstb
1 - Enables the Cycle Slip Prevention (CSP)
feature of the PFD
Table 39. Reg 1Dh VCO Tune Port Control Register
Bit
Type
Name
Default
Description
0
R/W voltage_force
Selects the source of control of the timing of the
mid-rail voltage,
0
voltage_force=0 selects Autotune state machine
voltage_force=1 selects voltage_enable from SPI
Used for mid-rail control of VCO during
autotuning
1
R/W voltage_enable
Forces mid-rail voltage on the charge pump
0
output from the SPI when voltage_force=1
Used for mid-rail control of VCO during
autotuning
Table 40. Reg 1Eh Temperature Sensor Register
Bit
Type
Name
Default
0
R/W tsens_spi_enable
0
Description
Enable the temperature sensor, draws ~2mA
current, must strobe tsens_spi_strobe Reg 00h
<3>
Table 41. Reg 1Fh LD, VCO & Ramp Busy Read Only Register
Bit
Type
Name
Default
Description
0
RO
ro_lock_detect
0
1 = locked, 0 = unlocked
3:1
RO
ro_dsm_overflow
0
1 = modulator overflow
4
RO
ro_spi_vco_busy
0
Set when VCO autotuning is running
5
RO
ro_ramp_busy
0
Sweeper status flag, set when ramp is busy,
cleared when at end of ramp or not used
Table 42. Reg 20h VCO Tune Caps Read Only Register (vcot)
Bit
Type
Name
Default
Description
5:0
RO
vcot_caps
Reads the values of the VCO switched resonator
0
bank determined by the autotune routine (see )
0 = max VCO freq
63 = min VCO freq
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