Dallas Semiconductor DS2434 Datasheet
www.dalsemi.com
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GND
Q
VDD
DS2434
Battery Identification Chip
FEATURES
Provides unique ID number to battery packs
Eliminates thermistors by sensing battery
temperature on-chip
256-bit nonvolatile user memory available
for storage of user data such as gas gauge
and manufacturing information
Operating range of -40°C to +85°C
Applications include portable computers,
portable/cellular phones, consumer
electronics, and handheld instrumentation.
Surface-mount package (209-mil SSOP16)
available
PIN DESCRIPTION
GND - Ground
DQ - Data In/Out
V
- Supply Voltage
DD
NC - No Connect
PACKAGE OUTLINE
BOTTOM VIEW
DQ 1 16 VDD
C2 15NC
C3 14NC
C4 13NC
C5 12NC
C6 11NC
C7 10NC
GND 8 9 GND
D
DS2434
PR-35 PACKAGE
See Mech. Drawings
Section
DS2434 16-Pin SSOP
See Mech. Drawings
Section
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DESCRIPTION
The DS2434 Battery Identification Chip provides a convenient method of tagging and identifying batter y
packs by manufacturer, chemistry, or other identifying parameters. The DS2434 allows the battery pack
to be coded with a unique identification number, and also store information regarding the battery life and
charge/discharge characteristics in its nonvolatile memory.
The DS2434 also performs the essential function of monitoring battery temperature, without the need for
a thermistor in the battery pack.
Information is sent to/from the DS2434 over a 1-Wire interface, so that battery packs need only have
three output connectors; power, ground, and the 1-Wire interface.
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DS2434
DETAILED PIN DESCRIPTION
PIN
14-PIN SOIC
1 1 GND
14 2 DQ Data Input/Output pin- for 1Wire communication port
13 3 VDD Supply pin- input power supply
PIN
PR35 SYMBOL DESCRIPTION
Ground pin
OVERVIEW
The DS2434 has five major components: 1) Scratchpad Memory, 2) Nonvolatile Memory, 3) On-board
SRAM, 4) Temperature Sensor, and 5) ID Register. All data is read and written least significant bit first.
Access to the DS2434 is over a 1-Wire interface. Charging parameters and other data such as battery
chemistry, gas gauge information, and other user data would be stored in the DS2434, allowing this
information to be permanently stored in the battery pack. Nonvolatile (E2) RAM holds information even
if the battery goes dead; as long as the battery remains within typical charge/discharge operating range,
the SRAM provides battery-backed storage of information.
DS2434 BLOCK DIAGRAM Figure 1
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DS2434 MEMORY PARTITIONING Figure 2
DS2434
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DS2434 ADDRESSABLE RAM MEMORY MAP Figure 3
DS2434
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DS2434 ADDRESSABLE RAM MEMORY MAP (cont’d) Figure 3
DS2434
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DS2434
MEMORY
The DS2434’s memory is divided into five pages, each page filling 32 bytes of address space. Not all of
the available addresses are used, howev er. Refer to the memory m ap of Figure 3 to see actual add resses
which are available for use.
The first three pages of memory consist of a scratchpad RAM and then either a nonvolatile RAM (pages 1
and 2) or SRAM (page 3). The scratchpads help insure data integrity when communicating over the 1Wire bus. Data is first written to the scratchpad where it can be read back. After the data has been
verified, a Copy Scratchpad command will transfer the data to the RAM (NV or SRAM). This process
insures data integrity when modifying the memory.
The fourth page of memory consists of registers which contain the measured temperature value and status
registers for the device; these registers are made from SRAM cells.
The fifth page of memory holds the ID number for the device and the cycle count registers in E2 RAM,
making these registers nonvolatile under all power conditions.
PAGE 1
The first page of memory has 24 bytes. It consists of a scratchpad RAM and a nonvolatile (E2) RAM.
These 24 bytes may be used to store any data the user wishes; such as battery chemistry descriptors,
manufacturing lot codes, gas gauge information, etc.
The nonvolatile portion of this page may be locked to prevent data stored here from being changed
inadvertently.
Both the nonvolatile and the scratchpad portions are organized identically, as shown in the memory map
of Figure 3. In this page, these two portions are referred to as NV1 and SP1, respectively.
PAGE 2
The second page of memory has 8 bytes. It consists of a scratchpad RAM and a nonvolatile (E2) RAM.
These eight bytes may be used to store an y data the user wishes, such as battery chemistry descriptors,
manufacturing lot codes, gas gauge information, etc.
PAGE 3
The third page of memory has a full 32 bytes. It consists of a scratchpad RAM and an SRAM. This
address space may be used to store any data the user wishes, provided that, should the battery go dead and
power to the DS2434 is lost, this data may also be lost without serious repercussions. Data which must
remain even if power to the DS2434 is lost should be placed in either Page 1 or Page 2.
This section of memory may be used to store gas gauge and self-discharge information. If the battery dies
and this information is lost, it is moot because the user can easily determine that the battery is dead.
PAGE 4
The fourth page of memory is used by the DS2434 to store the converted value of battery temperature. A
2-byte status register is also provided.
TEMPERATURE REGISTERS (60h-61h)
The DS2434 can measure temperature without external components. The resulting temperature
measurement is placed into two temperature registers. These registers are SRAM, and therefore will hold
the values placed in them until the battery voltage falls below the minimum VDD specified. The first
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