RT4539A

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is a registered trademark of Richtek Technology Corporation

www.richtek.com

DS4539A-01

December 2022

28

Protection

RT4539A embeds LED protection for LED OVP level, and Boost OVP. The LED protection can be set by the I2C, as

shown in Table 17.

Table 17. Protection

Address Bit

Name

Default Value

Description

R/W

0Ah

[4:

0]

Boost Over-Voltage

Protection

selection

39V

(0x1Dh)

Boost output over-voltage protection

0x00h to 0x1Eh: 10V~40V

R/W

[6:

5]

LED OVP Level

2.1V

(B00)

LED OVP level

B00: 2.1V

B01: 2.52V

B10: 2.8V

B11: 3.5V

R/W

[7:

7]

LED Short Protection

Disable

(B0)

LED Short Protection

B0: Disable

B1: Enable

R/W

When the Boost output voltage rises above the VOVP, the internal switch will be turned off. Once the Boost output

voltage drops below the VOVP, the internal switch will be turned on again. The Boost output voltage can be clamped

at the VOVP.

Boost Over-voltage

Protection selection [4: 0]

Boost OVP

(V)

0x00h

10

0x01h

11

0x02h

12

0x03h

13

0x04h

14

0x05h

15

0x06h

16

0x07h

17

0x08h

18

0x09h

19

0x0Ah

20

0x0Bh

21

0x0Ch

22

0x0Dh

23

0x0Eh

24

0x0Fh

25

Boost Over-voltage

Protection selection [4: 0]

Boost OVP

(V)

0x10h

26

0x11h

27

0x12h

28

0x13h

29

0x14h

30

0x15h

31

0x16h

32

0x17h

33

0x18h

34

0x19h

35

0x1Ah

36

0x1Bh

37

0x1Ch

38

0x1Dh

39

0x1Eh

40

0x1Fh

40