Datasheet

DATA IN
Start
DATA OUT ACK
RFA A1 A0 D4 D3 D2 D1 D0DA7
0
DA6
1
DA5
0
DA4
0
DA3
1
DA2
1
DA1
1
DA0
0
Device Address DATABYTE
EOS Start EOS
Start
TPS62410-Q1
www.ti.com SLVSAA8 –MARCH 2010
• Acknowledge is requested by a set RFA bit
• The transmitted device address matches with the device address of the device
• 16 bits were received correctly
In this case, the device turns on the internal ACKN-MOSFET and pulls the MODE/DATA pin low for the time
t
ACKN
, which is max. 520µs. The Acknowledge condition is valid after an internal delay time t
valACK
. This means
the internal ACKN-MOSFET is turned on after t
valACK
, when the last falling edge of the protocol was detected.
The master controller keeps the line low during this time.
The master device can detect the acknowledge condition with it’s input by releasing the MODE/DATA pin after
t
valACK
and read back a 0.
In case of an invalid device address or not correctly received protocol, no acknowledge condition will be applied,
thus the internal MOSFET will not be turned on and the external pullup resistor pulls MODE/DATA pin high after
t
valACK
. The MODE/DATA pin can be used again after the acknowledge condition ends.
NOTE
The acknowledge condition may only be requested in case the master device has an open
drain output.
In case of a push pull output stage it is recommended to use a series resistor in the MODE/DATA line to limit the
current to 500µA in case of an accidentally requested acknowledge to protect the internal ACKN-MOSFET.
MODE Selection
Because of the MODE/DATA pin is used for two functions, interface and a MODE selection, the device needs to
determine when it has to decode the bit stream or to change the operation mode.
The device enters forced PWM mode operation immediately whenever the MODE/DATA pin turns to high level.
The device stays also in forced PWM mode during the whole time of a protocol reception.
With a falling edge on the MODE/DATA pin the device starts bit decoding. If the MODE/DATA pin stays low for at
least t
timeout
, the device get’s an internal timeout and Power Save Mode operation is enabled.
A protocol which is sent within this time will be ignored, because the falling edge for the Mode change will be first
interpreted as start of the first bit. In this case it is recommended to send first the protocol and change at the end
of the protocol to Power Save Mode.
Figure 27. Easy Scale Protocol Overview
Table 2. Easy Scale Bit Description
BYTE BIT NAME TRANSMISSION DESCRIPTION
NUMBER DIRECTION
Device 7 DA7 IN 0 MSB device address
Address
6 DA6 IN 1
Byte
5 DA5 IN 0
4 DA4 IN 0
4Ehex 3 DA3 IN 1
2 DA2 IN 1
1 DA1 IN 1
0 DA0 IN 0 LSB device address
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