EVM AND LAYOUT RECOMMENDATIONS

TP2

TP3

C

3

0.1 F

m

C603

C0805

C

5

0.1 F

m

C

8

10 F

m

C

7

10 F

m

V

S-

J4

V

S-

C

12

0.1 F

m

C603

C0805

C

11

0.1 F

m

C

9

10 F

m

C

10

10 F

m

V

S+

V

S+

J8

V

S+

C

15

Open

C

16

Open

C

13

Open

C

14

Open

V

S-

J5

GND

R

1

R

2

R

12

1kW

R

13

1kW

R

14

1kW

R

15

1kW

R

25

0W

J9

J10

R

26

R

16

487W

R

20

52.3W

R

17

487W

R

22

2

1

3

5

6

4

R

21

R

7

5

4

6

2

3

1

R

3

R

4

0W

R

6

49.9W

C

1

0.22 F

m

R

8

C

2

C

4

0.22 F

m

V

S-

V

S-

V

S+

R

23

R

18

R

24

0W

R

9

R

5

0W

R

10

52.3W

R

11

52.3W

J6

R

19

J7

J1

J2

T2

T1

TP1

V

OUT+

V

OUT-

4

5

6

3

1

8

7

2

PW

CM

J11

JP1

J3

C

6

0.22 F

m

THS4521

THS4522

THS4524

Figure 77 shows the THS4521EVM schematic. PCB layers 1 through 4 are shown in Figure 78; Table 6 lists the

bill of materials for the THS4521EVM as supplied from TI. It is recommended to follow the layout of the external

components near to the amplifier, ground plane construction, and power routing as closely as possible. Follow

these general guidelines:

1. Signal routing should be direct and as short as possible into and out of the op amp circuit.

2. The feedback path should be short and direct.

3. Ground or power planes should be removed from directly under the amplifier input and output pins.

4. An output resistor is recommended in each output lead, placed as near to the output pins as possible.

5. Two 0.1-

µF power-supply decoupling capacitors should be placed as near to the power-supply pins as

possible.

6. Two 10-

µF power-supply decoupling capacitors should be placed within 1 inch of the device and can be

shared among multple analog devices.

7. A 0.22-

µF capacitor should be placed between the V

limits noise coupled into the pin.

8. The PD pin uses TTL logic levels; a bypass capacitor is not necessary if actively driven, but can be used for

robustness in noisy environments whether driven or not.

recommended.

Figure 77. THS4521EVM: Schematic

32

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