ADP5501 Analog Devices, ADP5501 Datasheet - Page 18

• Manufacturer Part Number: ADP5501
• Description: Programmable Current Backlight Driver with Ambient Light Sensor Input
• Manufacturer: Analog Devices

Specifications of ADP5501

• Vin Range: 2.7 to 5.5V
• Vout (v): 24 to 27
• Synchronous: No
• Package: 24-Lead LFCSP
• Led Configuration: Serial
• Topology: Inductive
• I2c Support: Yes
• Max Iout (ma): 30mA
• Brightness Control: I2C
• Switching Frequency: 1MHz
• Over Volt Protection (v): 24V

ADP5501
COMMUNICATON INTERFACE
Communication with the ADP5501 is done via its I
compatible serial interface. Figure 41 shows a typical write
sequence for programming an internal register.
1.
2.
3.
4.
5.
6.
7.
The cycle begins with a start condition, followed by the
chip write address (0x64).
The ADP5501 acknowledges the chip write address byte by
pulling the data line low.
The address of the register to which data is to be written is
sent next.
The ADP5501 acknowledges the register address byte by
pulling the data line low.
The data byte to be written to is sent next.
The ADP5501 acknowledges the data byte by pulling the
data line low.
A stop condition completes the sequence.
ST
0
1
CHIP ADDRESS
1
0
ST
0
0
1
1
0 = WRITE
0
CHIP ADDRESS
1
0
0
0
0
REGISTER ADDRESS
1
0 = WRITE
0
0
2
C-
0
Figure 41. I
Figure 42. I
REGISTER ADDRESS
Rev. 0 | Page 18 of 28
0
2
2
C Write Sequence
C Read Sequence
ST
0
CHIP ADDRESS
1
Figure 42 shows a typical read sequence for reading back an
internal register.
1.
2.
3.
4.
5.
6.
7.
8.
1
0
The cycle begins with a start condition, followed by the
chip write address (0x64).
The ADP5501 acknowledges the chip write address byte by
pulling the data line low.
The address of the register from which data is to be read is
sent next.
The ADP5501 acknowledges the register address byte by
pulling the data line low.
The cycle continues with a repeat start, followed by the
chip read address (0x65).
The ADP5501 acknowledges the chip read address byte by
pulling the data line low.
The ADP5501 places the contents of the previously
addressed register on the bus for readback.
There is a no acknowledge following the readback data
byte, and the cycle is completed with a stop condition.
0
ADP5501 RECEIVES DATA
0
1 = READ
1
0
0
ADP5501 SENDS DATA
0
SP
1
SP