For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824

Phone: 978-250-3343

Fax: 978-250-3373

Order On-line at www.hittite.com

Application Support: Phone: 978-250-3343 or apps@hittite.com

10

HMC701LP6CE

v09.1112

8 GHz 16-BIT FRACTIONAL-N PLL

Figure 4. Reference Path Block Diagram

VCO Path

the rF path from the Vco to the phase detector, is referred to as the Vco path. the Vco path consists of an input

isolation buffer and a multi-modulus prescaler, or simply the n divider. the n divider is controlled by the fractional

modulator. this path operates with inputs directly from the external Vco.

RF Input Stage

the synthesizer rF input stage routes the external Vco to the phase detector via a 16-bit fractional divider. the rF

input path is rated to operate nominally from 100 kHz to 8 GHz in fractional and 9 GHz in integer modes. the rF input

stage also provides isolation between the Vco and the prescaler. the rF input stage is a differential common emitter

stage, Dc coupled for maximum flexibility. the input is protected by ESD diodes as shown in Figure 5. normally the

rF input is ac coupled to a single ended external source. the rFinP buffer is well matched from a single ended

50 ohm source above about 3.5 GHz, with the complimentary input grounded. if a better match is required at low

frequency a simple shunt 50 ohm resistor can be used external to the package. if a differential external source is used

then the two input pins may be used for best performance.

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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.

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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

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