9
dc1812af
DEMO MANUAL DC1812A
Quikeval interface
LSB Information
LSB information for charge, voltage, current and tem-
perature registers as well as for all threshold registers is
displayed here. The ACR LSB updates depending on the
sense resistor and prescalar value chosen.
Status Register (A)
The individual status bits A[0:7] and their states are shown
here. A red indicator next to bits A[6:0] indicates the re-
spective alert is currently present and will latch the alert
pin if configured for alert. Bit A[7] is reserved.
The demo board alert pin indicator indicates the status of
the
AL/CC
pin. If the LTC2943
AL/CC
pin is set for alert
mode and an alert has been latched, the device will pull
down this pin which will light up the LED indicator on the
board as well as on the GUI. Click on ARA to send out an
SMBus alert on to the bus lines and the device will respond
with its address. The LED indicator on the demo board
and GUI alert pin indicator will then be cleared if the alert
is no longer present.
Control Register (B)
Configurations done in the control register section write
to the control register (register B). The control bits B[7:6]
set the LTC2943 ADC mode. The LTC2943 defaults to
automatic mode which enables full-time voltage, current
and temperature ADC conversions. Selecting scan mode
enables voltage, current and temperature conversions
cycles every 10s. After each conversion cycle the ADC
goes into sleep mode until it is time for the next conver-
sion cycle. Selecting manual mode initiates the ADC for
a snapshot of voltage, temperature, current and charge
once after which it returns to sleep mode. In sleep mode,
the LTC2943 continues to accumulate charge while the
ADC turns off.
Select a prescalar M value to scale the ACR according
to battery capacity and maximum current. M cannot be
changed during a scan.
The
AL/CC
pin can be configured for alert mode, charge
complete mode, or disabled. Select the corresponding
settings on the DC1812 jumper JP1.
The shutdown analog section is checked to disable the
analog portion of the LTC2943 and set the device in a
low current state. For normal operation leave unchecked.
Register Read/Write
Data in the internal registers of the LTC2943 is displayed
here in hexadecimal format. Data can also be entered and
written to the write registers. Enter data to be written in
hexadecimal, or select unit and enter data in decimal form.
Then click on the corresponding register button to write
to that register. Data is auto corrected if the maximum or
minimum full-scale is exceeded.
