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

7

HMC701LP6CE

v09.1112

8 GHz 16-BIT FRACTIONAL-N PLL

1. reference Path input Buffers

2. reference Path Divider

3. Vco Path input Buffer

4. Vco Path Multi-Modulus Prescaler/Divider

5. Δ∑ Fractional Modulator

6. Phase Frequency Detector

7. charge Pump

8. Main Serial Port

9. auxiliary Serial Port

10. temperature Sensor

11. Power on reset circuit

12. cW Sweeper Subsystem

13. auxiliary clock Generator

14. General Purpose output (GPo) Bus

15. Multiple Vco controller

Theory of Operation

the HMc701LP6cE synthesizer consists of the following functional blocks

Each of these blocks is described briefly in the following section.

Reference Path

the full reference Path block diagram is shown in Figure 1 the ultra low noise phase detector requires the best

possible reference signal. Since a given application may desire to use a square wave or a 50 ohm sinusoidal crystal

source, HMc701LP6cE offers two input ports, each one optimized for the lowest possible noise for the source type

being used.

For absolute best low noise performance, the sine wave path should be used.

the user should use only one ref path input, that is the input that matches their reference source type. note the input

is defaulted to the square wave input on power up. Should the sine reference path be used, it is necessary to enable

the sine input, shut down the square wave input and set the mux (rfp_buf_sin_en=1, rfp_buf_sq_en=0, rfp_buf_sin_

the reference path supports input frequencies of up to 250 MHz typical, however the maximum frequency at the

phase detector (PFD) depends upon the mode of operation, worst case at +85°c, 70 MHz in fractional mode and

100 MHz in integer mode. Hence reference inputs of greater than the PFD maximum frequency must use the

appropriate r divider setting.

Figure 1. Reference Sine Input Stages

the unused reference port is normally not connected.

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