DS2438Z+ Maxim Integrated Products, DS2438Z+ Datasheet - Page 15

• Manufacturer Part Number: DS2438Z+
• Description: IC MONITOR SMART BATTERY 8-SOIC
• Manufacturer: Maxim Integrated Products

Specifications of DS2438Z+

• Function: Fuel, Gas Gauge/Monitor
• Battery Type: Smart Batteries
• Voltage - Supply: 2.4 V ~ 10 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Operating Supply Voltage: 2.4 V to 10 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: No
• Mounting Style: SMD/SMT
• Temperature Monitoring: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS2438
Page 0 (00h)
The first page contains the most frequently accessed information of the DS2438, and most locations are
volatile read-only bytes with the exception of the Status/Configuration Register (Byte 0) and the
Threshold Register (Byte 7). The Status/Configuration Register is a nonvolatile read/write byte which
defines which features of the DS2438 are enabled and how they will function. The register is formatted as
follows:
X
ADB
NVB
TB
AD
EE
CA
IAD
MSb
LSb
IAD = Current A/D Control Bit. “1” = the current A/D and the ICA are enabled, and current
measurements will be taken at the rate of 36.41 Hz; “0” = the current A/D and the ICA have been
disabled. The default value of this bit is a “1” (current A/D and ICA are enabled).
CA = Current Accumulator Configuration. “1” = CCA/DCA is enabled, and data will be stored and can
be retrieved from page 7, bytes 4-7; “0” = CCA/DCA is disabled, and page 7 can be used for general
EEPROM storage. The default value of this bit is a “1” (current CCA/DCA are enabled).
EE = Current Accumulator Shadow Selector bit. “1” = CCA/DCA counter data will be shadowed to
EEPROM each time the respective register is incremented; “0”= CCA/DCA counter data will not be
shadowed to EEPROM. The CCA/DCA could be lost as the battery pack becomes discharged. If the CA
bit in the status/configuration register is set to “0”, the EE bit will have no effect on the DS2438
functionality. The default value of this bit is a “1” (current CCA/DCA data shadowed to EEPROM).
AD = Voltage A/D Input Select Bit. “1” = the battery input (VDD) is selected as the input for the
DS2438 voltage A/D converter; “0” = the general purpose A/D input (VAD) is selected as the voltage
A/D input. For either setting, a Convert V command will initialize a voltage A/D conversion. The default
value of this bit is a “1” (V
is the input to the A/D converter).
DD
TB = Temperature Busy Flag. “1” = temperature conversion in progress; “0” = temperature conversion
complete.
NVB = Nonvolatile Memory Busy Flag. “1” = Copy from Scratchpad to EEPROM in progress; “0” =
Nonvolatile memory not busy. A copy to EEPROM may take from 2 ms to 10 ms (taking longer at lower
supply voltages).
ADB = A/D Converter Busy Flag. “1” = A/D conversion in progress on battery voltage; “0” = conversion
complete, or no measurement being made. An A/D conversion takes approximately 10 ms.
X = Don’t care
Bytes 1 and 2 of page 0 contain the last completed temperature conversion in the format described in the
“Operation - Measuring Temperature” section. Bytes 3-4 contain the last completed voltage A/D
conversion result and bytes 5-6 contain the instantaneous current data. Byte 7 contains the Threshold
Register. Refer to the appropriate section for the data format of these locations.
NOTE:
The data in the scratchpad of the status and threshold register will determine the operation of the device.
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