MAX7324AEG+ Maxim Integrated Products, MAX7324AEG+ Datasheet - Page 7

• Manufacturer Part Number: MAX7324AEG+
• Description: IC I/O EXPANDER I2C 8B 24QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX7324AEG+

• Interface: I²C
• Number Of I /o: 8
• Interrupt Output: Yes
• Frequency - Clock: 400kHz
• Voltage - Supply: 1.71 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-QSOP
• Includes: POR
• Operating Supply Voltage: 1.71 V to 5.5 V
• Power Dissipation: 761.9 mW
• Operating Temperature Range: - 40 C to + 125 C
• Input Voltage: 1.65 V to 1.197 V
• Maximum Clock Frequency: 400 KHz
• Mounting Style: SMD/SMT
• Output Voltage: 0.3 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A latching interrupt output, INT, is programmed to flag
input data changes on 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 cleared when the MAX7324
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 four (see Table 2).
On power-up, the transition detection logic is reset, and
INT is deasserted. The interrupt mask register is set to
0xFF, enabling the interrupt output for transitions on all
eight input ports. The transition flags are cleared to
indicate no data changes. The power-up default states
of the eight push-pull outputs are set according to the
I
Table 3).
The MAX7324 contains an integral power-on-reset
(POR) circuit that ensures all registers are reset to a
known state on power-up. When V+ rises above V
(1.6V max), the POR circuit releases the registers and
2-wire interface for normal operation. When V+ drops
below V
to the POR defaults (Tables 2 and 3).
Table 1. MAX7319–MAX7329 Family Comparison (continued)
2
I
MAX7323
MAX7328
MAX7329
C slave address selection inputs, AD0 and AD1 (see
PART
2
C Port Expander with Eight Push-Pull Outputs
POR
ADDRESS
, the MAX7324 resets all register contents
0100xxx
0111xxx
110xxxx
SLAVE
I
2
C
_______________________________________________________________________________________
INPUTS
Up to 4
Up to 8
INTERRUPT
INPUT
MASK
Initial Power-Up
Power-On Reset
—
—
OUTPUTS
Up to 4
Up to 8
OPEN-
DRAIN
POR
OUTPUTS
PUSH-
PULL
The RST input voids any I
MAX7324, forcing the MAX7324 into the I
dition. A reset does not affect the interrupt output (INT).
When the serial interface is idle, the MAX7324 automat-
ically enters standby mode, drawing minimal supply
current.
Address inputs AD0 and AD2 determine the MAX7324
slave address and select which inputs have pullup
resistors. Pullups are enabled on the input ports in
groups of four (see Table 2).
The MAX7324 slave address is determined on each I
transmission, regardless of whether the transmission is
actually addressing the MAX7324. The MAX7324 distin-
guishes whether address inputs AD0 and AD2 are con-
nected to SDA or SCL instead of fixed logic levels V+
or GND during this transmission. This means that the
MAX7324 slave address can be configured dynamical-
ly in the application without cycling the device supply.
On initial power-up, the MAX7324 cannot decode the
address inputs AD0 and AD2 fully until the first I
transmission. AD0 and AD2 initially appear to be con-
nected to V+ or GND. This is important because the
—
4
Slave Address, Power-Up Default Logic
4 I/O, 4 output-only versions:
4 open-drain I/O ports with latching transition
detection interrupt and selectable pullups.
4 push-pull outputs with selectable power-up default
levels.
PCF8574-, PCF8574A-compatible versions:
8 open-drain I/O ports with nonlatching transition
detection interrupt and pullups on all ports.
Levels, and Input Pullup Selection
and Eight Inputs
CONFIGURATION
2
C transaction involving the
Standby Mode
2
C STOP con-
RST Input
2
2
C
C
7