MAX6956ATL Maxim Integrated Products, MAX6956ATL Datasheet - Page 9

• Manufacturer Part Number: MAX6956ATL
• Description: LED Drivers LED Static Display D river and I-O Port,
• Manufacturer: Maxim Integrated Products

Specifications of MAX6956ATL

• Number Of Segments: 28
• Low Level Output Current: 18000 uA
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Supply Current: 230 uA
• Maximum Power Dissipation: 2105 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: TQFN EP
• Minimum Operating Temperature: - 40 C

Figure 6. Slave Address
Figure 5. Acknowledge
MAX6956 is the recipient. When the MAX6956 is trans-
mitting to the master, the master generates the
acknowledge bit because the master is the recipient.
The MAX6956 has a 7-bit-long slave address (Figure 6).
The eighth bit following the 7-bit slave address is the
R/ W bit. It is low for a write command, high for a read
command.
The first 3 bits (MSBs) of the MAX6956 slave address
are always 100. Slave address bits A3, A2, A1, and A0
are selected by address inputs, AD1 and AD0. These
two input pins may be connected to GND, V+, SDA, or
SCL. The MAX6956 has 16 possible slave addresses
(Table 3) and therefore, a maximum of 16 MAX6956
devices may share the same interface.
A write to the MAX6956 comprises the transmission of
the MAX6956’s slave address with the R/ W bit set to
zero, followed by at least 1 byte of information. The first
BY TRANSMITTER
SDA
SCL
BY RECEIVER
28-Port LED Display Driver and I/O Expander
MSB
SDA
SDA
SCL
1
START CONDITION
2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or
S
_______________________________________________________________________________________
Message Format for Writing
0
0
1
Slave Address
the MAX6956
A3
2
A2
byte of information is the command byte. The com-
mand byte determines which register of the MAX6956
is to be written by the next byte, if received. If a STOP
condition is detected after the command byte is
received, then the MAX6956 takes no further action
(Figure 8) beyond storing the command byte.
Any bytes received after the command byte are data
bytes. The first data byte goes into the internal register of
the MAX6956 selected by the command byte (Figure 9). If
multiple data bytes are transmitted before a STOP condi-
tion is detected, these bytes are generally stored in subse-
quent MAX6956 internal registers because the command
byte address generally autoincrements (Table 4).
The MAX6956 is read using the MAX6956’s internally
stored command byte as address pointer, the same
way the stored command byte is used as address
pointer for a write. The pointer generally autoincre-
ments after each data byte is read using the same rules
as for a write (Table 4). Thus, a read is initiated by first
configuring the MAX6956’s command byte by perform-
A1
CLOCK PULSE FOR ACKNOWLEDGMENT
Message Format for Reading
LSB
A0
8
R/W
9
ACK
9