DS2760 Dallas Semiconducotr, DS2760 Datasheet - Page 15

• Manufacturer Part Number: DS2760
• Description: High Precision Li-Ion Battery Monitor
• Manufacturer: Dallas Semiconducotr

1-WIRE CRC GENERATION BLOCK DIAGRAM – Figure 14
HARDWARE CONFIGURATION
Because the 1-Wire bus has only a single line, it is important that each device on the bus be able to drive
it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must connect to the
bus with open-drain or tri-state output drivers. The DS2760 used an open-drain output driver as part of
the bi-directional interface circuitry shown in Figure 15. If a bi-directional pin is not available on the bus
master, separate output and input pins can be tied together.
The 1-Wire bus must have a pull-up resistor at the bus-master end of the bus. For short line lengths, the
value of this resistor should be approximately 5 k . The idle state for the 1-Wire bus is high. If, for any
reason, a bus transaction must be suspended, the bus MUST be left in the idle state in order to properly
resume the transaction later. If the bus is left low for more than 120 s, slave devices on the bus begin to
interpret the low period as a Reset Pulse, effectively terminating the transaction.
1-WIRE BUS INTERFACE CIRCUITRY – Figure 15
TRANSACTION SEQUENCE
The protocol for accessing the DS2760 via the 1-Wire port is as follows:
The sections that follow describe each of these steps in detail.
Initialization
Net Address Command
Function Command
Transaction/Data
MSb
Rx
Tx
BUS MASTER
XOR
Rx = Receive
Tx = Transmit
+5V
15 of 25
4.7K
XOR
1 A
Typ.
DS2760 1-WIRE PORT
100 OHM
MOSFET
LSb
Rx
Tx
XOR
input
DS2760