Advertisement
Quick Links
Multicell Battery Gas Gauge with Temperature,
Description
Demonstration circuit 1812A (Figure 1) features the
LTC
2943. 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
2
SMBus/I
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.
DEMO MANUAL DC1812A
Voltage and Current Measurement
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
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.
Figure 1. DC1812A
LTC2943
dc1812af
1
Advertisement
Related Manuals for Linear Technology DC1812A
Summary of Contents for Linear Technology DC1812A
- Page 1 Design files for this circuit board are available at http://www.linear.com/demo/DC1812A 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.
-
Page 2: Quick Start Procedure
8 If AL/CC is set for charge complete, use pushbutton switch S1 to simulate a logic low from a controller to indicate a fully charged battery. Figure 2. DC1812A Basic Setup dc1812af... - Page 3 DEMO MANUAL DC1812A Quikeval interface The DC1812A can be connected to a DC590 and used Interface Design with the QuikEval software. The DC590 connects to a PC The QuikEval interface consists of three tabs along with a through USB. QuikEval automatically detects the demo...
- Page 4 DEMO MANUAL DC1812A Quikeval interface InFo CoLumn Temperature Display Data from the temperature ADC (register U and V) is dis- Accumulated Charge Since Start (ACR Display) played here. It can be displayed in two formats: Celsius The “Accumulated Charge Since Start” text box displays and Kelvin.
- Page 5 DEMO MANUAL DC1812A Quikeval interface CouLomB CounTER TAB to time in mA. If the current exceeds 1A, then the graph auto scales to display the current in units of amperes. If This tab contains time based graphical plots of charge a scan is restarted, the plots start from the beginning.
- Page 6 DEMO MANUAL DC1812A Quikeval interface BATTERy GAuGE TAB where Q is in mAh. Similarly, for applications with a small battery but high maximum current the q can get This tab contains controls to set up the battery gas gauge quite large with respect to the battery capacity causing a and consists of two sections: User Input and Initialization.
- Page 7 DEMO MANUAL DC1812A Quikeval interface To avoid unnecessary calculation, the interface conveniently Battery Gas Gauge suggests a prescalar value to use based on the entered The gas gauge shows the battery’s state of charge. The battery capacity and sense resistor value. This prescalar...
- Page 8 DEMO MANUAL DC1812A Quikeval interface REGISTER AnD ConTRoL TAB Sense Resistor The register and control tab provides a detailed view of the By default, the demo board is populated with a 100mΩ LTC2943 device registers as well as provides convenient sense resistor to measure a maximum full-scale current of means to read and write to them.
- Page 9 DEMO MANUAL DC1812A Quikeval interface LSB Information enables voltage, current and temperature conversions cycles every 10s. After each conversion cycle the ADC LSB information for charge, voltage, current and tem- goes into sleep mode until it is time for the next conver- perature registers as well as for all threshold registers is sion cycle.
-
Page 10: Parts List
DEMO MANUAL DC1812A parts list ITEm REFEREnCE PART DESCRIPTIon mAnuFACTuRER/PART numBER CAP., CHIP X7R, 0.1µF 0603 AVX, 06033C104KAT2A CAP., X7R, 1.0µF, 100V, 10%, 1206 MURATA, GRM31CR72A105KA01 LED, RED, LIGHT EMITTING DIODES PANASONIC, LN1251CTR DIODE, BAT54C SOT23 DIODES INC.,BAT54C-7-F E1-E4 TURRET, TESTPOINT .094"... -
Page 11: Schematic Diagram
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. - Page 12 Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for EnGInEERInG DEVELoPmEnT oR EVALuATIon PuRPoSES onLy and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods.
Need help?
Do you have a question about the DC1812A and is the answer not in the manual?
Questions and answers