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

25

HMC701LP6CE

v09.1112

8 GHz 16-BIT FRACTIONAL-N PLL

Figure 17. Single Step Ramp Mode

the user should be aware that the synthesized ramp is subject to normal phase locked loop dynamics. if the loop

bandwidth in use is much wider than the rate of the steps then the locking will be very fast and the ramp will have a

staircase shape. if the update rate is higher than the loop bandwidth, as is normally the case, then the loop will not

fully settle before a new frequency step is received. Hence the swept output will have a small lag and will sweep in a

near continuous fashion.

MAIN SERIAL PORT

the HMc701LP6cE features a four wire serial port for simple communication with the host controller. register types

may be read only, Write only, read/Write or Strobe, as described in the registers descriptions.

typical main serial port operation can be run with ScLK at speeds up to 50 MHz. Serial port registers are described

in the section rEGiStEr MaP.

LD_SDO Pin Operation

configuration of the LD_SDo pin requires manipulation of both reg2h[1:0] and reg1ah[13:12], as follows:

Serial data output (SDo) when a serial read occurs and high impedance at all other times:

reg2h[1:0] = 0x (x=don’t care)

reg1ah[13:12] = 0x (x=don’t care)

Serial data output (SDo) when a serial read occurs and LD status at all other times (LD_SDo pin automatically mux’ed

between LD and SDo):

reg2h[1:0] = 11

reg1ah[13:12] = 01

LD status always:

reg2h[1:0] = 11

reg1ah[13:12] = 1x

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