APPLICATION INFORMATION

RT

SYNC

SS/ENA

VBIAS

PWRGD

COMP

VSENSE

AGND

20

19

18

17

4

3

2

1

VIN

VIN

VIN

PH

PH

PH

PH

PH

BOOT

PGND

PGND

PGND

PwrPAD

16

15

14

10

9

8

7

6

5

13

12

11

U1

TPS54310PWP

C8

10

µF

C7

0.047

µF

L1

1.2

µH

+

C9

180

µF

4 V

C11

1000 pF

1

2

GND

J3

C5

3900 pF

R2

3.74 k

Ω

R4

3.74 k

Ω

C4

100 pF

R3

71.5 k

Ω

C3

0.1

µF

1

R1

10 k

Ω

J1

2

1

GND

PWRGD

+

C2

1

Optional

C6

R6

2700 pF

732

Ω

R5

10 k

Ω

R7

49.9

Ω

VIN

INPUT VOLTAGE

SETTING THE OUTPUT VOLTAGE

FEEDBACK CIRCUIT

O

R5 x 0.891

R4 =

V

- 0.891

(1)

TPS54310-EP

Figure 10 shows the schematic diagram for a typical TPS54310 application. The TPS54310 (U1) can provide up

to 3 A of output current at a nominal output voltage of 3.3 V. For proper thermal performance, the thermal pad

under the TPS54310 integrated circuit needs to be soldered well to the printed-circuit board.

Figure 10. TPS54310 Schematic

The input to the circuit is a nominal 5 VDC, applied at

The output voltage of the TPS54310 can be set by

J1. The optional input filter (C2) is a 220-µF POSCAP

feeding back a portion of the output to the VSENSE

capacitor, with a maximum allowable ripple current of

pin using a resistor divider network. In the application

3 A. C8 is the decoupling capacitor for the TPS54310

circuit of Figure 10, this divider network is comprised

and must be located as close to the device as

of resistors R5 and R4. To calculate the resistor

possible.

values to generate the required output voltage use

Equation 1.

The resistor divider network of R5 and R4 sets the

output voltage for the circuit at 3.3 V. R5, along with

Start with a fixed value of R5 and calculate the

R2, R6, C4, C5, and C6 forms the loop compensation

required R4 value. Assuming a fixed value of 10 k

Ω

network for the circuit. For this design, a Type 3

for R5, the following table gives the appropriate R4

topology is used.

value for several common output voltages:

OUTPUT VOLTAGE (V)

R4 VALUE (K

Ω)

1.2

28.7

1.5

14.7

1.8

9.76

2.5

5.49

3.3

3.74

8

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