MAX7321 Maxim, MAX7321 Datasheet - Page 5

• Manufacturer Part Number: MAX7321
• Description: The MAX7321 2-wire serial-interfaced peripheral features eight open-drain I/O ports with selectable internal pullups and transition detection
• Manufacturer: Maxim

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 industry standard parts.
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.
Table 1. MAX7319–MAX7329 Family Comparison
8-PORT EXPANDERS
MAX7319
MAX7320
MAX7321
MAX7322
PART
MAX7319–MAX7329 Family Comparison
ADDRESS
110xxxx
101xxxx
110xxxx
110xxxx
SLAVE
I
2
I
C
2
_______________________________________________________________________________________
C Port Expander with 8 Open-Drain I/Os
Detailed Description
INPUTS
Up to 8
—
8
4
INTERRUPT
INPUT
MASK
Yes
Yes
—
—
OUTPUTS
Up to 8
OPEN-
DRAIN
—
—
—
OUTPUTS
PUSH-
PULL
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
(0x60 to 0x6F) using the address select inputs AD0 and
AD2, and is accessed over an I
400kHz. The RST input clears the serial interface in
—
—
8
4
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.
Output-only versions:
8 push-pull outputs with selectable power-up default
levels.
Push-pull outputs offer faster rise time than open-
drain outputs, and require no pullup resistors.
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.
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.
APPLICATION
Functional Overview
2
C serial interface up to
2
C slave addresses
5