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

8

8 - 3

Worst Case Step Error

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

0

1

2

3

4

5

6

FREQUENCY (GHz)

16 dB

4 dB

8 dB

30

40

50

60

70

80

0

1

2

3

4

5

6

FREQUENCY (GHz)

HMC624LP4 / 624LP4E

v09.0210

0.5 dB LSB GaAs MMIC 6-BIT

DIGITAL ATTENUATOR, DC - 6 GHz

Serial Control Interface

The HMC624LP4E contains a 3-wire SPI compatible digital interface (SERIN, CLK, LE). The serial control interface

is activated when P/S is kept high. The 6-bit serial word must be loaded MSB first. The positive-edge sensitive CLK

and LE requires clean transitions. If mechanical switches are used, sufficient debouncing should be provided. When

LE is high, 6-bit data in the serial input register is transferred to the attenuator. When LE is high CLK is masked to

prevent data transition during output loading.

When P/S is low, 3-wire SPI interface inputs (SERIN, CLK, LE) are disabled and the input register is loaded with

parallel digital inputs (D0-D5). When LE is high, 6-bit parallel data changes the state of the part per truth table.

For all modes of operations, the state will stay constant while LE is kept low.