1
dc1812af
DEMO MANUAL DC1812A
Description
LTC2943
Multicell Battery Gas Gauge with Temperature,
Voltage and Current Measurement
Demonstration circuit 1812A (Figure 1) features the
. The LTC2943 has an operating range of 3.6V
to 20V making it perfectly suited for multicell battery ap-
plications. A precision analog coulomb counter integrates
current measured through a sense resistor between the
battery’s positive terminal and the load or charger. The
LTC2943 measures voltage, current and temperature with
an internal 14-bit No Latency ∆∑™ ADC. The measurements
are stored in internal registers accessible via the onboard
SMBus/I
2
C interface.
The LTC2943 has programmable high and low thresholds
for all measured quantities. If a programmed threshold
is exceeded, the device reports an alert using either the
SMBus alert protocol or by setting a flag in the internal
status register.
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No
Latency ∆∑ and QuikEval are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
The LTC2943 requires only a single low value sense resis-
tor to set the measured current range. The default value
assembled on the DC1812A is 100mΩ for a maximum
current measurement of 500mA. The LTC2943 has a
software-configurable charge complete/alert pin. When
the pin is set for charge complete, a jumper connects
the pushbutton which simulates a logic low input at the
AL/CC
pin. This sets the ACR register to FFFFh which
indicates a full battery. When the pin is configured for
alert, the same jumper is used to connect a red LED that
indicates an alert is present.
The DC1812A is a part of the QuikEval™ system for quick
evaluation with a host controller through a PC using the
DC590.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1812A
Figure 1. DC1812A
