Datasheet

PC Board Layout Considerations
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 out-
puts are to be heavily loaded. Keep the track length from
the ISET pin to the R
ISET
resistor as short as possible,
and take the GND end of the register either to the ground
plane or directly to the GND pins.
Power-Supply Considerations
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.
Table 4. Autoincrement Rules
Table 3. MAX7300 Address Map
Figure 9. ‘n’ Data Bytes Received
COMMAND BYTE ADDRESS RANGE AUTOINCREMENT BEHAVIOR
x0000000 to x1111110 Command address autoincrements after byte read or written
x1111111 Command address remains at x1111111 after byte written or read
PIN
CONNECTION
DEVICE ADDRESS
AD1 AD0 A6 A5 A4 A3 A2 A1 A0
GND GND 1 0 0 0 0 0 0
GND V+ 1 0 0 0 0 0 1
GND SDA 1 0 0 0 0 1 0
GND SCL 1 0 0 0 0 1 1
V+ GND 1 0 0 0 1 0 0
V+ V+ 1 0 0 0 1 0 1
V+ SDA 1 0 0 0 1 1 0
V+ SCL 1 0 0 0 1 1 1
SDA GND 1 0 0 1 0 0 0
SDA V+ 1 0 0 1 0 0 1
SDA SDA 1 0 0 1 0 1 0
SDA SCL 1 0 0 1 0 1 1
SCL GND 1 0 0 1 1 0 0
SCL V+ 1 0 0 1 1 0 1
SCL SDA 1 0 0 1 1 1 0
SCL SCL 1 0 0 1 1 1 1
S A A A P0
SLAVE ADDRESS COMMAND BYTE DATA BYTE
ACKNOWLEDGE FROM MAX7300
D15 D14 D13 D12 D11 D10 D9 D8 D1 D0D3 D2D5 D4D7 D6
HOW COMMAND BYTE AND DATA BYTE MAP INTO MAX7300’s REGISTER
ACKNOWLEDGE FROM MAX7300
R/W
‘n’ BYTES
AUTOINCREMENT MEMORY WORD ADDRESS
ACKNOWLEDGE FROM MAX7300
www.maximintegrated.com
Maxim Integrated │ 12
MAX7300 2-Wire-Interfaced, 2.5V to 5.5V,
20-Port or 28-Port I/O Expander