DS2777G+T&R Maxim Integrated Products, DS2777G+T&R Datasheet - Page 40

• Manufacturer Part Number: DS2777G+T&R
• Description: IC FUEL GAUGE LI+ 2CELL 14-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2777G+T&R

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4 V ~ 9.2 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
Protector and Optional SHA-1 Authentication
Figure 28. Clear/Lock Secret, Set/Clear Overdrive Commands
Figure 29. 1-Wire Initialization Sequence
The 1-Wire bus requires strict signaling protocols to
ensure data integrity. The four protocols used by the
DS2775/DS2776 are as follows: the initialization
sequence (reset pulse followed by presence pulse),
write-zero, write-one, and read data. The bus master
initiates all these types of signaling except the pres-
ence pulse.
40
______________________________________________________________________________________
DQ
1-Wire
RESET
PRESENCE
PULSE
COMMAND
SKIP-ROM
LINE TYPE LEGEND:
1-Wire Signaling
BUS MASTER ACTIVE LOW
RESISTOR PULLUP
t
RSTL
OVERDRIVE COMMAND
t
PDH
SECRET COMMAND
OR SET/CLEAR
CLEAR/LOCK
Figure 29 shows the initialization sequence required to
begin any communication with the DS2775/DS2776. A
presence pulse following a reset pulse indicates that
the DS2775/DS2776 are ready to accept a Net Address
command. The bus master transmits (Tx) a reset pulse
for t
goes into receive mode (Rx). The 1-Wire bus line is
then pulled high by the pullup resistor. After detecting
the rising edge on the DQ pin, the DS2775/DS2776 wait
for t
PDH
RSTL
t
DS2775/DS2776 ACTIVE LOW
PDL
and then transmit the presence pulse for t
. The bus master then releases the line and
t
RSTH
WAIT FOR EEPROM
t
EEC
COPY TIME
PK+
PK-
PDL
.