Detailed Description
MAX7319–MAX7329 Family Comparison
The MAX7319–MAX7323 family consists of five pin-
compatible, eight-port expanders. Each version is opti-
mized for different applications. The MAX7328 and
MAX7329 are second sources to the PCF8574 and
PCF8574A.
The MAX7324–MAX7327 family consists of four pin-
compatible, 16-port expanders that integrate the func-
tions of the MAX7320 and one of either the MAX7319,
MAX7321, MAX7322, or MAX7323.
Functional Overview
The MAX7320 is a general-purpose port expander
operating from a +1.71V to +5.5V supply that provides
eight push-pull output ports. The MAX7320 is rated to
sink a total of 100mA and source a total of 50mA from
all eight combined outputs.
The MAX7320 is set to one of 16 I
2
C slave addresses
(0x50 to 0x5F) using address select inputs AD0 and AD2,
and is accessed over an I
2
C serial interface up to
400kHz. Note the MAX7320 offers a different range of I
2
C
slave addresses than the MAX7319, MAX7321,
MAX7322, and MAX7323 (these expanders use the
address range 0x60 to 0x6F).
MAX7320
I
2
C Port Expander with Eight Push-Pull Outputs
_______________________________________________________________________________________ 5
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:
Eight 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:
Eight push-pull outputs with selectable power-up
default states.
Push-pull outputs offer faster rise time than open-
drain outputs, and require no pullup resistors.
MAX7321 110xxxx Up to 8 — Up to 8 —
I/O versions:
Eight 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
Four input-only, four output-only versions:
Four input ports with programmable latching
transition detection interrupt and selectable pullups.
Four push-pull outputs with selectable power-up
default levels.
Table 1. MAX7319–MAX7329 Family Comparison
