5 - 19

HMC704LP4E

v04.0215

For price, delivery and to place orders: Analog Devices, Inc., One Technology Way, Norwood, MA 02062

978-250-3343 tel • 978-250-3373 fax • Order online at www.analog.com/hittitemw

Application support: Phone: 978-250-3343 or RFMG-apps@analog.com

Ref Path ’R’ Divider

The reference path “R” divider is based on a 14 bit counter and can divide input signals of up to 350 MHz input by values

RF Path

by-2 with a selectable bypass. If the VCO input is below 4 GHz the RF divide-by-2 should be by-passed for reduced

power consumption and improved performance in fractional mode. The RF divide-by-2 is followed by the N divider, a 19

bit divider that can operate in either integer or fractional mode with up to 4 GHz inputs. Finally the N divider is followed

by the Phase Detector (PD), which has two inputs, the RF path from the VCO (V) and the reference path (R) from the

crystal. The PD can operate at speeds up to 80 MHz in fractional Mode A, 100 MHz in fractional Mode B and 115 MHz in

integer mode.

RF Input Stage

The RF input stage provides the path from the external VCO to the phase detector via the RF or ’N’ divider. The RF input

path is rated to operate up to 8 GHz across all conditions. The RF input stage is a differential common emitter stage with

Ohm resistor placed across the inputs can be used if desired. In most applications the input is used single-ended into

either the VCOIP or VCOIN pin with the other input connected to ground through a DC blocking capacitor. The preferred

input level for best spectral performance is -10 dBm nominally.

Figure 29. RF Input Stage

Figure 28. RF Path

RF Buffer

/2 or

8GHz

8GHz

4GHz

Bypass

19 Bit /N

PD

80MHz/100MHz Fractional

115MHz Integer

V

R

Ref Path

sEL

CONTROL

VCOIP

VCOIN

RF Divide by 2 N Divider

Phase Detector

CP

UP

DN

CP

VPPCP

Charge Pump

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responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registered trademarks are the property of their respective owners.

For price, delivery, and to place orders: Analog Devices, Inc.,

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106

Phone: 781-329-4700 • Order online at www.analog.com

Application Support: Phone: 1-800-ANALOG-D