Functional Overview

The MAX7313 is a general-purpose input/output (GPIO)

peripheral that provides 16 I/O ports, P0–P15, con-

17th output-only port, INT/O16, can be configured as

an interrupt output or as a general-purpose output port.

All output ports sink loads up to 50mA connected to

external supplies up to 5.5V, independent of the

MAX7313’s supply voltage. The MAX7313 is rated for a

ground current of 350mA, allowing all 17 outputs to sink

20mA at the same time. Figure 1 shows the output

structure of the MAX7313. The ports default to inputs on

power-up.

Port Inputs and Transition Detection

Input ports registers reflect the incoming logic levels of

the port pins, regardless of whether the pin is defined

16-Port I/O Expander with LED Intensity

Control, Interrupt, and Hot-Insertion Protection

6

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Pin Description

Figure 1. Simplified Schematic of I/O Ports

D

Q

Q

FF

DATA FROM

SHIFT REGISTER

DATA FROM

SHIFT REGISTER

WRITE

CONFIGURATION

PULSE

WRITE PULSE

READ PULSE

CONFIGURATION

REGISTER

D

Q

Q

FF

INPUT PORT

REGISTER

D

Q

Q

FF

OUTPUT

PORT

REGISTER

OUTPUT PORT

REGISTER DATA

I/O PIN

Q2

GND

INPUT PORT

REGISTER DATA

TO INT

PIN

QSOP

QFN

NAME

FUNCTION

122

INT/O16

Output Port. Open-drain output rated at 7V, 50mA. Configurable as interrupt

output or general-purpose output.

21, 2, 3

18, 23, 24

AD0, AD1,

AD2

Address Inputs. Sets device slave address. Connect to either GND, V+,

SCL, or SDA to give 64 logic combinations. See Table 1.

4–11, 13–20

1–8, 10–17

P0–P15

Input/Output Ports. P0–P15 are open-drain I/Os rated at 5.5V, 50mA.

12

9

GND

Ground. Do not sink more than 350mA into the GND pin.

22

19

SCL

23

20

SDA

24

21

V+

Positive Supply Voltage. Bypass V+ to GND with a 0.047µF ceramic

capacitor.

—

PAD

Exposed pad

Exposed pad on package underside. Connect to GND.