Detailed Description

MAX7319–MAX7329 Family Comparison

The MAX7324–MAX7327 family consists of four pin-

compatible, 16-port expanders that integrate the func-

tions of the MAX7320 and one of either MAX7319,

MAX7321, MAX7322, or MAX7323.

Functional Overview

The MAX7325 is a general-purpose port expander oper-

ating from a +1.71V to +5.5V supply with eight push-pull

outputs and eight open-drain I/O ports. Each open-drain

output is rated to sink 20mA, and the entire device is

rated to sink 100mA into all ports combined. The outputs

drive loads connected to supplies up to +5.5V.

(see Tables 2 and 3) using the address select inputs

face up to 400kHz. The eight outputs and eight I/Os

have different slave addresses. The eight push-pull out-

puts have the 101xxxx addresses and the eight inputs

have addresses with 110xxxx. The RST input clears the

serial interface in case of a bus lockup, terminating any

serial transaction to or from the MAX7325.

Configure any port as a logic input by setting the port

output logic-high (logic-high for an open-drain output is

high impedance). When the MAX7325 is read through

the serial interface, the actual logic levels at the ports

are read back.

and 8 Open-Drain I/Os

_______________________________________________________________________________________

5

PART

SLAVE

ADDRESS

INPUTS

INPUT

INTERRUPT

MASK

OPEN-

DRAIN

OUTPUTS

PUSH-

PULL

OUTPUTS

CONFIGURATION

16-PORT EXPANDERS

MAX7324

8

Yes

—

8

8 input and 8 push-pull output versions:

8 input ports with programmable latching transition

detection interrupt and selectable pullups.

8 push-pull outputs with selectable default logic

levels.

Offers maximum versatility for automatic input

monitoring. An interrupt mask selects which inputs

cause an interrupt on transitions, and transition flags

identify which inputs have changed (even if only

for a transient) since the ports were last read.

MAX7325

101xxxx

and

110xxxx

Up to 8

—

Up to 8

8

8 I/O and 8 push-pull output versions:

8 open-drain I/O ports with latching transition

detection interrupt and selectable pullups.

8 push-pull outputs with selectable default logic

levels.

Open-drain outputs can level shift the logic-high

state to a higher or lower voltage than V+ using

external pullup resistors, but pullups draw current

when output is low. Any open-drain port can be used

as an input by setting the open-drain output to logic-

high. Transition flags identify which open-drain port

inputs have changed (even if only for a transient)

since the ports were last read.

Table 1. MAX7319–MAX7329 Family Comparison