Datasheet

Detailed Description
MAX7319–MAX7329 Family Comparison
The MAX7319–MAX7323 family consists of five pin-
compatible, eight-port expanders. Each version is optimized
for different applications. The MAX7328 and MAX7329
are industry standard parts.
The MAX7324–MAX7327 family consists of four pin-
compatible, 16-port expanders that integrate the
functions of the MAX7320 and one of either the MAX7319,
MAX7321, MAX7322, or MAX7323.
Functional Overview
The MAX7321 is a general-purpose port expander
operating from a +1.71V to +5.5V supply that provides
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, independent
of the MAX7321’s supply voltage.
The MAX7321 is set to one of 16 I
2
C slave addresses
(0x60 to 0x6F) using the address select inputs AD0 and
AD2, and is accessed over an I
2
C serial interface up
to 400kHz. The RST input clears the serial interface in
Table 1. MAX7319–MAX7329 Family Comparison
PART
I
2
C
SLAVE
ADDRESS
INPUTS
INPUT
INTERRUPT
MASK
OPEN-
DRAIN
OUTPUTS
PUSH-
PULL
OUTPUTS
APPLICATION
8-PORT EXPANDERS
MAX7319 110xxxx 8 Yes — —
Input-only versions:
8 input ports with programmable latching transition
detection interrupt and selectable pullups.
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
momentarily) since the ports were last read.
MAX7320 101xxxx — — — 8
Output-only versions:
8 push-pull outputs with selectable power-up default
levels.
Push-pull outputs offer faster rise time than open-
rain outputs, and require no pullup resistors.
MAX7321 110xxxx Up to 8 — Up to 8 —
I/O versions:
8 open-drain I/O ports with latching transition
detection interrupt and selectable pullups.
Open-drain outputs can level shift the logic-high state
to a higher or lower voltage than V+ using external
pullup resistors. Any port can be used as an input by
setting the open-drain output to logic-high. Transition
flags identify which inputs have changed (even
momentarily) since the ports were last read.
MAX7322 110xxxx 4 Yes — 4
4 input-only, 4 output-only versions:
4 input ports with programmable latching transition
detection interrupt and selectable pullups;
4 push-pull outputs with selectable power-up default
levels.
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MAX7321 I
2
C Port Expander with 8 Open-Drain I/Os