HMC832LP6GETR datasheet(22/49 Pages) AD

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Data Sheet

HMC832

Charge Pump Gain

Charge pump up and down gains are set by Register 0x09[6:0]

and Register 0x09[13:7], respectively. The current gain of the

pump in amps/radian is equal to the gain setting of this register

(Register 0x09) divided by 2π.

Typical CP gain setting is set to 2 mA to 2.5 mA; however, lower

values can also be used. Note that values less than 1 mA may

result in degraded phase noise performance.

For example, if both Register 0x09[13:7] and Register 0x09[6:0]

are set to 50 decimal, the output current of each pump is 1 mA,

and the phase frequency detector gain is kP = 1 mA/2π radians,

or 159 μA/rad. See the Charge Pump (CP) and Phase Detector

(PD) section for more information.

Figure 43. Charge Pump Gain and Offset Control

REF PATH

VCO PATH

LOOP

FILTER

UP GAIN

REG0x09[13:7]

UP OFFSET REG0x09[21]

0µA TO 635µA

5µA STEP

REG0x09[20:14]

DN OFFSET REG0x09[22]

0µA TO 635µA

5µA STEP

REG0x09[20:14]

0mA TO 2.54mA

20µA STEP

0mA TO 2.54mA

20µA STEP

DN GAIN

REG0x09[6:0]

Rev. A | Page 21 of 48

HMC832LP6GETR Datasheet(PDF) 22 Page - Analog Devices