AN2846

Application guidelines

Doc ID 15130 Rev 1

13/35

Figure 17.

Regulator output voltage

Figure 18 shows the schematic diagram of a solution for applications where greater current

is needed. The bypass transistor allows extra current while maintaining a 5 V regulated

voltage (see Figure 19).

additional input protection device, like SMAJ30A, is needed to comply with voltage surges

The dissipated power in the bypass transistor PZT2N2907A is 550 mW.

Components used:

●

●

1.4

SPI functional description

Three registers (refer to Figure 1) are used to transfer input data and control data to the

16-bit data frame. The data frames are transmitted through four interface signals: /CS, SCK,

MOSI, and MISO.

4.5

4.6

4.7

4.8

4.9

5.0

5.1

V

-3%

dd

9.0

V

(V)

dd

I

(mA)

dd

V

versus I

dd

dd

Figure 18.

Figure 19.

R

E

R

C

V

CC

2N2907A

V

SMAJ30A

SCLT3

0.00

5.00

10.00

15.00

20.00

25.00

4.800

4.850

4.900

4.950

5.000

5.050

5.100

0.00

5.00

10.00

15.00

20.00

25.00

I

(mA)

DD

V

(V)

DD

V

DD