© 2018 Integrated Device Technology, Inc.

3

September 11, 2018

F1240 Datasheet

Pin Descriptions

Table 1.

Pin Descriptions

Number

Name

Description

1

GA3 / DATA 4dB Attenuation control bit for Channel A (Parallel Mode) or DATA (Serial Mode).

2

GA4 / CLK

8dB Attenuation control bit for Channel A (Parallel Mode) or CLK (Serial Mode).

3

GA5

16dB Attenuation control bit for Channel A.

4

For the parallel mode set for logic HIGH or float (internal pullup resistor)

Set for logic Low for the serial mode.

5, 13, 20,

21, 28

GND

Internally grounded. This pin must be grounded with a via as close to the pin as possible.

6

GB5

16dB Attenuation control bit for Channel B.

7

GB4

8dB Attenuation control bit for Channel B.

8

GB3

4dB Attenuation control bit for Channel B.

9

GB2

2dB Attenuation control bit for Channel B.

10

GB1

1dB Attenuation control bit for Channel B.

11

IN_B+

Channel B Differential Input +. Pin is AC coupled.

12

IN_B-

Channel B Differential Input -. Pin is AC coupled.

14

Power supply input. Bypass to ground with capacitors as close as possible to pin.

15

ISET_B

16

GB0

0.5dB Attenuation control bit for Channel B.

17

OUT_B+

required.

18

OUT_B-

required.

19

STBY_B

Pull low to Power Down Channel B. Float or Pull HIGH to enable Channel B.

22

STBY_A

Pull low to Power Down Channel A. Float or Pull HIGH to enable Channel A.

23

OUT_A-

required.

24

OUT_A+

required.

25

GA0

0.5dB Attenuation control bit for Channel A.

26

ISET_A

27

Connect this pin to the 5V DC Power Bus. Bypass capacitor is required.

29

IN_A-

Channel A Differential Input -. Pin is AC coupled.

30

IN_A+

Channel B Differential Input +. Pin is AC coupled.

31

GA1

1dB Attenuation control bit for Channel A.

32

GA2 / CSb

2dB Attenuation control bit for Channel A (Parallel Mode) or Chip Select, CSb (Serial Mode).

– EPAD

Exposed paddle. Internally connected to ground. Solder this exposed paddle to a printed circuit board

(PCB) pad that uses multiple ground vias to provide heat transfer out of the device into the PCB ground

planes. These multiple ground vias are also required to achieve the specified RF performance.