MAX7322AEE+ Maxim Integrated Products, MAX7322AEE+ Datasheet - Page 13

• Manufacturer Part Number: MAX7322AEE+
• Description: IC I/O EXPANDER I2C 4B 16QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX7322AEE+

• 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-QSOP
• Includes: POR
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

data is the current port data transmitted to the master,
so any input port changes occurring during the trans-
mission are detected. INT remains high until the STOP
condition.
A write to the MAX7322 starts with the master transmit-
ting the MAX7322’s slave address with the R/W bit set
low. The MAX7322 acknowledges the slave address,
and samples the ports (takes a snapshot) during
acknowledge. INT deasserts during the slave acknowl-
edge. The master proceeds to transmit 1 or more bytes
of data. The MAX7322 acknowledges these subse-
quent bytes of data and updates the four output ports
and the 4-bit interrupt mask register with each new byte
until the master issues a STOP condition (Figure 8).
Figure 8. Writing to the MAX7322
INTERNAL WRITE
S = START CONDITION
P = STOP CONDITION
SHADED = SLAVE TRANSMISSION
N = NOT ACKNOWLEDGE
FROM PORT
DATA OUT
TO PORT
SDA
SCL
START CONDITION
S
______________________________________________________________________________________
1
2
SLAVE ADDRESS
3
4
Writing to the MAX7322
5
6
4 Push-Pull Outputs and 4 Inputs
7
R/W ACKNOWLEDGE
0
8
A
FROM SLAVE
DATA TO INTERRUPT MASK
DATA 1
I
The MAX7322’s SDA, SCL, AD0, AD2, input RST, INT,
and input ports I2–I5 are overvoltage protected to +6V
independent of V+. This allows the MAX7322 to operate
from a lower supply voltage, such as +3.3V, while the
I
ven from a higher logic level, such as +5V.
The MAX7322 can operate from a higher supply volt-
age, such as +3V, while the I
of the four input ports I2–I5 are driven from a lower
logic level, such as +2.5V. Apply a minimum voltage of
0.7 x V+ to assert a logic-high on any input. For exam-
ple, a MAX7322 operating from a +5V supply may not
recognize a +3.3V nominal logic-high. One solution for
input-level translation is to drive the MAX7322 inputs
from open-drain outputs. Use a pullup resistor to V+ or
a higher supply to ensure a high logic voltage of
greater than 0.7 x V+.
2
2
C interface and/or some of the four input ports are dri-
C Port Expander with
t
PV
A
ACKNOWLEDGE
FROM SLAVE
Port Input and I
Translation from Higher or Lower
Applications Information
DATA TO INTERRUPT MASK
DATA 1 VALID
DATA 2
2
C interface and/or some
2
C Interface Level
t
PV
Logic Voltages
A
ACKNOWLEDGE
FROM SLAVE
DATA 2 VALID
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