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HMC983LP5E

v00.0911

DC - 7 GHZ FRACTIONAL-N DIVIDER

AND FREQUENCY SWEEPER

For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824

978-250-3343 tel • 978-250-3373 fax • Order On-line at www.hittite.com

Application Support: apps@hittite.com

Table 6. HMC983LP5E Sweeper Configuration Sequence

Steps

Description

Sweeper Modes

2-Way Sweep Mode

User Defined Sweep Mode

1-Way Sweep Mode

1

Lock to start

• set the integer (Reg 05h) and fractional (Reg 06h and Reg 07h) divider values.

• Optionally, if required the seed (Reg 0Ah and Reg 0Bh) can also be programmed

2

Place the DSM

in sweep mode

• Write Reg 0Eh[11] = 1

3

Configure

sweep mode

• Disable single step ramp mode (Reg

0Eh[24] = 0), so that each frequency

increment

will

be

incremented

automatically

• Enable 2-way sweep mode (Disable

1-way sweep mode (Reg 0Eh[25]

= 0))

• To place the HMC983LP5E in

automatic

sweep

mode

write

Reg 0Eh[2:3] = ‘11’. To place the

HMC983LP5E in triggered mode

write Reg 0Eh[2:3] = ‘00’.

• Enable the single step ramp mode

(Reg 0Eh[24] = 1), so that each

frequency increment will require a

trigger

• Enable 1-way sweep mode (Reg

0Eh[25] = 1), or enable 2-Way

sweep mode (Reg 0Eh[25] = 1)

• To place the HMC983LP5E in

triggered mode write Reg 0Eh[2:3] =

‘00’. Automatic User Defined Sweep

mode is not supported.

• Disable single step ramp mode (Reg

0Eh[24] = 0), so that each frequency

increment

will

be

incremented

automatically

• Enable 1-way sweep mode (Reg

0Eh[25] = 1)

• To place the HMC983LP5E in

triggered mode write Reg 0Eh[2:3] =

‘00’. Automatic 1-Way Sweep mode

is not supported.

4

Program

Sweep

Direction

• Reg 0Eh[26] = 1 begin sweep in positive direction, Reg 0Eh[26] = 0 begin sweep in negative direction

5

Configure

symmetrical/

asymmetrical

sweep

• Program ramp mode (symmetrical - Reg 0Eh[22] = 1, asymmetrical - Reg

0Eh[22] = 0). If symmetrical ramp mode is selected (Reg 0Eh[22] = 1), only

Up sweep parameters will be used for both positive and negative sweeps,

and hence down sweep parameters don’t need to be programmed. In

symmetrical ramp mode the positive and negative ramps are identical and

opposite in direction.

• Program Reg 0Eh[22] = 1.

Asymmetrical sweep is not defined

in 1-Way Sweep mode

6

Program

Up Sweep

Parameters

• Set dwell time(dwell time[47:0] = Reg 10h[29:0], dwell time[17:0] = Reg 11h[17:0])

• Set step size (step size[47:18] = Reg 12h[29:0], step size[17:0] = Reg 13h[17:0])

• Set the number of steps in a sweep (number of steps[47:18] = Reg 14h[29:0], number of steps[17:0] = Reg 15h[17:0])

7

Program

Down Sweep

Parameters

(Only if using

asymmetrical

sweep (if Reg

0Eh[22] = 0) in

Step 5)

• Set dwell time (dwell time[47:0] = Reg 06h[47:18], dwell time[17:0] = Reg

07h[17:0])

• Set step size (step size[47:18] = Reg 19h[29:0], step size[17:0] = Reg

1Ah[17:0])

• Set the number of steps in a sweep (number of steps[47:18] = Reg 0Ch[29:0],

number of steps[17:0] = Reg 0Dh[17:0])

• Asymmetrical sweep is not defined

in 1-Way Sweep mode

8

Configure and

apply trigger

• To use SPI trigger write Reg 0Eh[13] = 0 to select SPI trigger. SPI trigger is executed by writing to Reg 0Eh[12] = 1.

• To use external trigger on pin D4 write Reg 0Eh[13] = 1 to configure pin D4 as an external trigger. Write Reg 08h[13]

= 0h to configure pin D4 to be an input. Applying master enable to GPIO pins (Reg 01h[4] = 1 ) is required.

• Enable trigger delay (Reg 0Eh[7] = 1), or disable trigger delay (Reg 0Eh[7] = 0).

• If using trigger delay, write delay value to Reg 05h[20:0], where Reg 05h[20:0] = number of delayed reference

periods. Writing Reg 05h[20:0] = 1 for example ensures that the trigger is applied at the instant of the rising edge

of the next reference rising edge.

HMC983LP5E sweep parameters are defined in the following way:

Initial frequency of the synthesizer