MAX7322ATE+ Maxim Integrated Products, MAX7322ATE+ Datasheet - Page 7

• Manufacturer Part Number: MAX7322ATE+
• Description: IC I/O EXPANDER I2C 4B 16TQFN-EP
• Manufacturer: Maxim Integrated Products

Specifications of MAX7322ATE+

• Interface: I²C
• Number Of I /o: 4
• Interrupt Output: Yes
• Frequency - Clock: 400kHz
• Voltage - Supply: 1.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Includes: POR
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

When the MAX7322 is read through the serial interface
the actual logic levels at the ports are read back.
The four input ports offer latching transition detection
functionality. All input ports are continuously monitored
for changes. An input change sets 1 of 4 flag bits that
identify the changed input(s). All flags are cleared upon
a subsequent read or write transaction to the MAX7322.
A latching interrupt output, INT, is programmed to flag
input data changes on the four input ports through an
interrupt mask register. By default, data changes on any
input port force INT to a logic low. The interrupt output
INT and all transition flags are deasserted when the
MAX7322 is next accessed through the serial interface.
Internal pullup resistors to V+ are selected by the
address select inputs, AD0 and AD2. Pullups are
enabled on the input ports in groups of two (see Table 2).
Output port power-up logic states are selected by the
address select inputs AD0 and AD2. Ports default to
logic-high or logic-low on power-up in groups of two
(see Table 2).
On power-up, the transition detection logic is reset, and
INT is deasserted. The interrupt mask register is set to
0x3C, enabling the interrupt output for transitions on all
four input ports. The transition flags are cleared to indi-
cate no data changes. The power-up default state of
the four push-pull outputs are set according to the I
slave address selection inputs, AD0 and AD2 (Table 2).
The MAX7322 contains an integral POR circuit that
ensures all registers are reset to a known state on
Table 1. MAX7319–MAX7329 Family Comparison (continued)
16-PORT EXPANDERS
MAX7324
MAX7325
MAX7326
MAX7327
PART
ADDRESS
101xxxx
110xxxx
SLAVE
and
I
2
C
_______________________________________________________________________________________
INPUTS
Up to 8
Up to 4
8
4
Power-On Reset (POR)
INTERRUPT
INPUT
MASK
Initial Power-Up
Yes
Yes
—
—
4 Push-Pull Outputs and 4 Inputs
OUTPUTS
OPEN-
DRAIN
Up to 8
Up to 4
—
—
2
C
OUTPUTS
PUSH-
PULL
I
12
12
8
8
power-up. When V+ rises above V
POR circuit releases the registers and 2-wire interface
for normal operation. When V+ drops to less than V
the MAX7322 resets all register contents to the POR
defaults (Table 2).
The active-low RST input operates as a reset that voids
any current I
forcing the MAX7322 into the I
reset action does not clear the interrupt output (INT).
When the serial interface is idle, the MAX7322 automat-
ically enters standby mode, drawing minimal supply
current.
Address inputs AD0 and AD2 determine the MAX7322
slave address, select which inputs have pullup resis-
tors and set the default logic state for outputs. Pullups
are enabled on the input ports in groups of two (see
Table 2). The MAX7319, MAX7321, MAX7322, and
MAX7323 use a different range of slave addresses
(110xxxx) than the MAX7320 (101xxxx).
The MAX7322 slave address is determined on each I
transmission, regardless of whether the transmission is
actually addressing the MAX7322. The MAX7322 distin-
guishes whether address inputs AD2 and AD0 are con-
nected to SDA or SCL instead of fixed logic levels V+ or
GND during this transmission. This means that the
MAX7322 slave address can be configured dynamically
in the application without cycling the device supply.
2
C Port Expander with
I
2
WRITE
C DATA
—
—
—
—
2
C transaction involving the MAX7322,
Slave Address and Input Pullup
Selection/Default Logic State
I
2
C DATA
READ
—
—
—
—
Software equivalent to a
MAX7320 plus a MAX7319.
Software equivalent to a
MAX7320 plus a MAX7321.
Software equivalent to a
MAX7320 plus a MAX7322.
Software equivalent to a
MAX7320 plus a MAX7323.
2
C STOP condition. The
POR
APPLICATION
Standby Mode
(1.6V max), the
RST Input
POR
2
C
7
,