DS2786BG+T&R Maxim Integrated Products, DS2786BG+T&R Datasheet - Page 20

• Manufacturer Part Number: DS2786BG+T&R
• Description: IC FUEL GAUGE OCV-BASED 10-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2786BG+T&R

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Stand-Alone OCV-Based Fuel Gauge
A write transaction transfers 1 or more data bytes to the
DS2786B. The data transfer begins at the memory
address supplied in the MAddr byte. Control of the SDA
signal is retained by the master throughout the transac-
tion, except for the acknowledge cycles.
A read transaction transfers 1 or more bytes from the
DS2786B. Read transactions are composed of two
parts—a write portion followed by a read portion—and
are therefore inherently longer than a write transaction.
The write portion communicates the starting point for
the read operation. The read portion follows immediate-
ly, beginning with a Repeated START, Slave Address
with R/W set to 1. Control of SDA is assumed by the
DS2786B beginning with the Slave Address
Acknowledge cycle. Control of the SDA signal is
retained by the DS2786B throughout the transaction,
except for the acknowledge cycles. The master indi-
cates the end of a read transaction by responding to
the last byte it requires with a no acknowledge. This
signals the DS2786B that control of SDA is to remain
with the master following the acknowledge clock.
The write data protocol is used to write to register and
shadow RAM data to the DS2786B starting at memory
address MAddr. Data0 represents the data written to
MAddr, Data1 represents the data written to MAddr +
1, and DataN represents the last data byte, written to
MAddr + N. The master indicates the end of a write
transaction by sending a STOP or Repeated START
after receiving the last acknowledge bit:
The MSB of the data to be stored at address MAddr
can be written immediately after the MAddr byte is
acknowledged. Because the address is automatically
incremented after the LSB of each byte is received by
the DS2786B, the MSB of the data at address MAddr +
20
S SAddr W A MAddr A Data0 A Data1 A … DataN A P
Read: SAddr W A MAddr A Sr SAddr R A Data0 N P
______________________________________________________________________________________
Write: S SAddr W A MAddr A Data0 A P
Write Portion
Basic Transaction Formats
Write Data Protocol
Read Portion
1 can be written immediately after the acknowledgment
of the data at address MAddr. If the bus master contin-
ues an autoincremented write transaction beyond
address 4Fh, the DS2786B ignores the data. Data is
also ignored on writes to read-only addresses and
reserved addresses, as well as a write that autoincre-
ments to the Function Command Register (address
FEh). Incomplete bytes and bytes that are not acknowl-
edged by the DS2786B are not written to memory. As
noted in the Memory Map section, writes to EEPROM
locations modify the shadow RAM only.
The read data protocol is used to read register and
shadow RAM data from the DS2786B starting at memo-
ry address specified by MAddr. Data0 represents the
data byte in memory location MAddr, Data1 represents
the data from MAddr + 1, and DataN represents the
last byte read by the master:
Data is returned beginning with the MSB of the data in
MAddr. Because the address is automatically incre-
mented after the LSB of each byte is returned, the MSB
of the data at address MAddr + 1 is available to the
host immediately after the acknowledgment of the data
at address MAddr. If the bus master continues to read
beyond address FFh, the DS2786B outputs data values
of FFh. Addresses labeled Reserved in the memory
map (Table 3) return undefined data. The bus master
terminates the read transaction at any byte boundary
by issuing a no acknowledge followed by a STOP or
Repeated START.
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
S SAddr W A MAddr A Sr SAddr R A Data0 A Data1
10 TDFN
PACKAGE CODE
...DataN N P
Package Information
T1033+1
Read Data Protocol
DOCUMENT NO.
21-0137