6 Bit Digital Step Attenuator

1 MHz to 4000 MHz

8

Rev 1, May 2017

IDTF1912NCGI

Datasheet

Serial Mode Default Startup Condition:

When the device is first powered up it will default to the Maximum Attenuation of 31.5 dB independent of the

Table 4 - Default Control Word for the Serial Mode

D5

(MSB)

D4

D3

D2

D1

D0

(LSB)

Attenuation

(dB)

1

1

1

1

1

1

31.5

For the F1912 the user has the option of running in one of two parallel modes. Direct Parallel Mode or

Latched Parallel Mode.

Direct Parallel Mode:

mode the device will immediately react to any voltage changes to the parallel control pins [pins 1, 15, 16, 17,

19, 20]. Use direct parallel mode for the fastest settling time.

Latched Parallel Mode:

 Adjust pins [pins 1, 15, 16, 17, 19, 20] to the desired attenuation setting. (Note the device will not

Table 5 - Truth Table for the Parallel Control Word

D5

D4

D3

D2

D1

D0

Attenuation

(dB)

0

0

0

0

0

0

0

0

0

0

0

0

1

0.5

0

0

0

0

1

0

1

0

0

0

1

0

0

2

0

0

1

0

0

0

4

0

1

0

0

0

0

8

1

0

0

0

0

0

16

1

1

1

1

1

1

31.5