MAX1739EEP+ Maxim Integrated Products, MAX1739EEP+ Datasheet - Page 22

• Manufacturer Part Number: MAX1739EEP+
• Description: Display Drivers Wide Brightness Rang e CCFL Backlight Con
• Manufacturer: Maxim Integrated Products

Specifications of MAX1739EEP+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

be used to read or write the brightness, SHMD, status,
or ID registers.
Table 6 summarizes the command byte’s register
assignments, as well as each register’s power-on state.
The MAX1739 also supports the receive-byte protocol
for quicker data transfers. This protocol accesses the
register configuration pointed to by the last command
byte. Immediately after power-up, the data byte
returned by the receive-byte protocol is the contents of
the brightness register, left justified (i.e., BRIGHT4 will
be in the MSB position of the data byte) with the
remaining bits containing a 1, STATUS1, and STATUS0.
Wide Brightness Range
CCFL Backlight Controllers
Figure 12. SMBus Write Timing
Figure 13. SMBus Read Timing
22
SMBCLK
SMBDATA
SMBCLK
SMBDATA
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
E = SLAVE PULLS SMBDATA LINE LOW
______________________________________________________________________________________
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
t
t
SU:STA
SU:STA
A
A
t
HD:STA
t
HD:STA
t
t
LOW
LOW
B
B
t
t
HIGH
HIGH
t
SU:DAT
t
SU:DAT
C
C
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
I = SLAVE PULLS SMBDATA LINE LOW
t
HD:DAT
E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER
D
D
E
E
F
F
This gives the same result as using the read-byte proto-
col with a 0b10XXXXXX (0x80) command. Use caution
with shorter protocols in multimaster systems since a
second master could overwrite the command byte with-
out informing the first master. During shutdown, the ser-
ial interface remains fully functional. The part also
supports limited read/write-word protocol. Read-word
works similar to read-byte except the second byte
returned is 0xFF. Write-word also works similar to write-
byte. The second data byte is acknowledged and
updated after the first data byte is acknowledged and
updated.
t
HD:DAT
t
HD:DAT
G
G
H
J = ACKNOWLEDGE CLOCKED INTO MASTER
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION, DATA EXECUTED BY SLAVE
M = NEW START CONDITION
t
SU:DAT
I = ACKNOWLEDGE CLOCK PULSE
J = STOP CONDITION
K = NEW START CONDITION
H
I
J
I
K
t
SU:STO
t
SU:STO
J
L
t
BUF
t
BUF
M
K