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

12

HMC701LP6CE

v09.1112

8 GHz 16-BIT FRACTIONAL-N PLL

synthesizer requires very low phase noise from the crystal, hence it is desirable to isolate other circuits from the

crystal itself and allow the synthesizer sole use of the low phase noise crystal.

gpo_sel=1 also routes the 250 MHz 14-bit reference path divider to GP02 and the 16-bit 7 GHz Vco path prescaler

output to GP01. this option allows the synthesizer to function as a stand alone fractional or integer prescaler and

provides visibility into the prescaler and reference path timing for sensitive applications.

Figure 6. gpo_01 Outputs

Lock Detect Windows (gpo_sel=2)

frequency detector UP and Dn output control signals (Figure 14) to be routed to pins GPo1, GPo3 and GPo2

respectively. this option gives insight into the Lock Detection Process and could allow the synthesizer to be used with

an external charge pump.

Figure 7. gpo_02 Outputs

Anti-cycle Slip Waveforms (gpo_sel = 3)

as described in section Cycle Slip Prevention (cSP). three waveforms, reference path freq > Vco path freq, vco

path freq > ref path freq, and a PFD strobe which holds the PFD at maximum gain, are routed to GPo3, GPo2, and

GPo1 respectively. these lines will be active during frequency pull-in and will indicate instantaneously which signal,

reference or vco path is greater in frequency. the PFD strobe gives insight into when the PFD is near maximum gain

at 2π. the PFD strobe will be active until the Vco pulls into lock.

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

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