AAT2601B Datasheet, PDF (30/39 Pages) Skyworks Solutions Inc. – Total Power Solution for Portable Applications

DATA SHEET
AAT2601B
Total Power Solution for Portable Applications
I²C Serial Interface
and Programmability
Serial Interface
Many of the features of the AAT2601B can be controlled
via the I²C serial interface. The I²C serial interface is a
widely used interface where it requires a master to initi-
ate all the communications with the slave devices. The
I²C protocol consists of 2 active wire SDA (serial data
line) and SCL (serial clock line). Both wires are open
drain and require an external pull up resistor to V_CC
(SYSOUT may be used as V_CC). The SDA pin serves I/O
function, and the SCL pin controls and references the I²C
bus. I²C protocol is a bidirectional bus which allows both
read and write actions to take place, but the AAT2601B
supports the write protocol only. Since the protocol has a
dedicated bit for Read or Write access (R/W), when com-
municating with AAT2601B, this bit must be set to “0”.
The timing diagram in Figure 7 depicts the transmission
protocol.
START and STOP Conditions
START and STOP conditions are always generated by the
master. Prior to initiating a START condition, both the
SDA and SCL pin are idle mode (idle mode is when there
is no activity on the bus and SDA and SCL are pulled to
V_CC via external resistor). As depicted in Figure 7, a
START condition is defined to be when the master pulls
the SDA line low and after a short period pulls the SCL
line low. A START condition acts as a signal to all IC’s
that something is about to be transmitted on the BUS.
A STOP condition, also shown in Figure 7, is when the
master releases the bus and SCL changes from low to
high followed by SDA low to high transition. The master
does not issue an ACKNOWLEGE and releases the SCL
and SDA pins.
START MSB
Chip
Address
ACK from slave
LSB W ACK MSB
Register
Address
ACK from slave
LSB ACK MSB
Data
SCL
ACK from slave
LSB ACK STOP
SDA
10011000
including R/W bit,
Chip Address = 0x98
Figure 7: I²C Timing Diagram.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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202181B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013