DC2343A  FW 1.0.2 / GUI 1.0.10
LTC3335 Nanopower Buck-Boost DC/DC with Integrated Coulomb Counter
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index.md
1 DC2343A APPLICATION FIRMWARE HOMEPAGE {#mainpage}
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4 Demonstration Circuit DC2343A is a complete system level solution for a Nanopower Buck-Boost DC/DC with Integrated Coulomb Counter. The DC2343A contains a PIC16F1459 embedded processor for communication to the PC over USB and the LTC3335 via its I2C port. The GUI is capable of reading and writing all the control registers on the LTC3335 as well as displaying and resetting all its alarm registers. The firmware and software for the embedded system and the GUI are available at the LTC3335 solutions page located at <a href="http://www.linear.com/product/LTC3335#demoboards" target="_blank">http://www.linear.com/product/LTC3335#demoboards</a>.
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6 The DC2343A uses two Analog-to-Digital Converter channels to sample the Battery and Output voltages. The voltage samples improve the functionality of the GUI, and allow optimal software correction to the measured coulombs. By adding the software correction the first order known errors are compensated for over the operating range and the resultant coulomb count is accurate to within 3%.
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8 The DC2343A contains an LTC3335 which is a high efficiency, low quiescent current (680nA) buck-boost DC/DC converter with an integrated precision cou-lomb counter which monitors accumulated battery discharge in long life battery powered applications. The buck-boost can operate down to 1.8V on its input and provides eight pin selectable output voltages with up to 50mA of output current. The coulomb counter stores the accumulated battery discharge in an internal register accessible via an I2C interface. The LTC3335 features a programmable discharge alarm threshold. When the threshold is reached, an interrupt is generated at the IRQ pin. To accommodate a wide range of battery types and sizes, the peak input current can be selected from as low as 5mA to as high as 250mA and the full-scale coulomb counter has a range from 1.1mAh (with 5mA IPEAK) to 1793Ah (with 250mA IPEAK).
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10 ![Figure 1: DC2343A PCB](.\Include\DC2343A_PCB.png)
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12 SOFTWARE OVERVIEW
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14 The DC2343A source files are pictured in in Figure 2. While all files are provided, only the files <a class="el" href="LTC3335_8c.html">LTC3335.c</a>, <a class="el" href="LTC3335_8h.html">LTC3335.h</a>, and <a class="el" href="LTC3335_8vb.html">LTC3335.vb</a> are documentated as they are the files most applicable for reuse by a customer in their application.
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16 The PIC16F1459 Firmware (FW), executing in the microcontroller on the DC2343A PCB, is written in C for the XC8 compiler v1.33 with an MPLab X v2.26 project.
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18 MPLab X can be freely downloaded from Microchip Technology: (<a href="http://www.microchip.com/pagehandler/en-us/devtools/dev-tools-parts.html" target="_blank">http://www.microchip.com/pagehandler/en-us/devtools/dev-tools-parts.html</a>). During the installation process, MPLab X will detect that a compiler is not installed and will offer to download and install the free version of XC8.
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20 The GUI Software (GUI SW), developed for Windows XP/7/8 computers with v4.5 of the .NET framework, is written in Visual Basic using Microsoft Visual Studio 2010.
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22 Visual Basic Express 2010 can be freely downloaded from Microsoft to allow builds of the GUI software: (<a href="https://www.visualstudio.com/en-us/products/visual-studio-express-vs.aspx" target="_blank">https://www.visualstudio.com/en-us/products/visual-studio-express-vs.aspx</a>).
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24 ![Figure 2: DC2343A Source Code Diagram](.\Include\Source_Code_Diagram.png)