MAX7300AAI-T Maxim Integrated, MAX7300AAI-T Datasheet - Page 12

• Manufacturer Part Number: MAX7300AAI-T
• Description: Interface - I/O Expanders 2.5-5.5V 20/28 Port I/O Expander
• Manufacturer: Maxim Integrated
• Series: MAX7300r

Specifications of MAX7300AAI-T

• Operating Supply Voltage: 2.5 V to 5.5 V
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SSOP-28
• Output Current: 10 mA
• Power Dissipation: 727 mW

Ensure that all the MAX7300 GND connections are
used. For TQFN versions, connect the underside
exposed pad to GND. A ground plane is not necessary,
but may be useful to reduce supply impedance if the
MAX7300 outputs are to be heavily loaded. Keep the
track length from the ISET pin to the R
short as possible, and take the GND end of the register
either to the ground plane or directly to the GND pins.
2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or
28-Port I/O Expander
Figure 9. ‘n’ Data Bytes Received
Table 3. MAX7300 Address Map
Table 4. Autoincrement Rules
12
HOW COMMAND BYTE AND DATA BYTE MAP INTO MAX7300’s REGISTER
COMMAND BYTE ADDRESS RANGE
______________________________________________________________________________________
GND
GND
GND
GND
AD1
SDA
SDA
SDA
SDA
SCL
SCL
SCL
SCL
V+
V+
V+
V+
x0000000 to x1111110
CONNECTION
PC Board Layout Considerations
S
x1111111
PIN
ACKNOWLEDGE FROM MAX7300
SLAVE ADDRESS
GND
GND
GND
GND
AD0
SDA
SDA
SDA
SDA
SCL
SCL
SCL
SCL
V+
V+
V+
V+
R/W
ISET
0
A6
Command address autoincrements after byte read or written
Command address remains at x1111111 after byte written or read
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
resistor as
A
D15 D14 D13 D12 D11 D10 D9
A5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
ACKNOWLEDGE FROM MAX7300
COMMAND BYTE
The MAX7300 operates with power-supply voltages of
2.5V to 5.5V. Bypass the power supply to GND with a
0.047µF capacitor as close to the device as possible.
Add a 1µF capacitor if the MAX7300 is far away from
the board’s input bulk decoupling capacitor.
A4
AUTOINCREMENT BEHAVIOR
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DEVICE ADDRESS
D8
A3
A
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Power-Supply Considerations
D7
AUTOINCREMENT MEMORY WORD ADDRESS
D6
ACKNOWLEDGE FROM MAX7300
D5
A2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
DATA BYTE
D4
‘n’ BYTES
D3
D2
A1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
D1
D0
A
A0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
P