5 Pin Configuration and Functions

FB_B3

FB_B2

SYNCCLKIN

VCCA

VOUT_VLDO

ENABLE

nERR/GPO2

VMON1/GPO1

FB_B1

CS_SPI/WD_DIS

nRSTOUT

SDO_SPI

SCK_SPI

AGND

SDI_SPI

nINT

VIO_LDO

1

2

3

4

5

6

7

8

9

10

11

12

13

14

23

22

21

20

19

18

17

16

15

AGND

25

24

26

28

27

Figure 5-1. RXV Package, 28-Pin VQFN-HR (Top View)

Table 5-1. Pin Functions

PIN

I/O

TYPE

DESCRIPTION

CONNECTION

IF NOT USED

NAME

NO.

SCK_SPI

1

I

Digital

Clock signal for SPI interface.

Ground

SDO_SPI

2

O

Digital

Output data signal for SPI interface.

Floating

FB_B1

3

—

Analog

Output voltage feedback (positive) for BUCK1.

Ground

CS_SPI/

WD_DIS

4

I

Digital

Primary function: Chip select signal for SPI interface.

VCCA

I

Digital

Alternative programmable function: Watchdog Deactivation Input.

Not applicable

AGND

5

—

Ground

Ground.

Ground

NRSTOUT

6

O

Digital

Reset output.

Floating

nINT

7

O

Digital

Interrupt output and CAN PHY control or both.

Floating

SDI_SPI

8

I

Digital

Input data signal for SPI interface.

Ground

VIO_LDO

9

—

Analog

IO supply from the internal LDO or from external source. LDO active: regulator

filter node. LDO inactive: input for connecting to an external IO supply source, with

input filtering capacitor placed.

Not applicable

VOUT_BST

10

—

Analog

BOOST active: BOOST output (internally connected as VIO_LDO input). BOOST

inactive and VIO_LDO inactive: short with VIO_LDO. BOOST inactive and

VIO_LDO active: input for connecting to an external supply used as VIO_LDO

input.

External supply

SW_BST

11

—

Analog

When BOOST active: BOOST input. When BOOST inactive: short with

VOUT_BST.

VOUT_BST

LP87743-Q1, LP87744-Q1, LP87745-Q1

SNVSC48B – OCTOBER 2021 – REVISED JUNE 2024

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