LTC3337 no-OS Example Project

See projects/ltc3337 (doxygen) for the Doxygen documentation.

Supported Evaluation Boards

Overview

The LTC3337 is a primary battery state of health (SOH) monitor with a built-in precision coulomb counter. It is designed to be placed in series with a primary battery with minimal associated series voltage drop. The coulomb counter tallies all accumulated battery discharge and stores it in an internal register accessible via an I2C interface. A discharge alarm threshold is programmable, generating an interrupt at the IRQ pin when reached.

The LTC3337 also monitors battery voltage, battery impedance, and die temperature, all accessible via I2C. The battery input voltage range is 1.8 V to 5.5 V with only 100 nA quiescent current. The peak input current limit is pin-selectable from 5 mA to 100 mA (8 settings: 5, 10, 15, 20, 25, 50, 75, 100 mA).

Applications

  • Low power primary battery powered systems (e.g., 1x LiSOCl2, 2-3x Alkaline)

  • Remote industrial sensors (e.g., meters, alarms)

  • Asset trackers

  • Electronic door locks

  • Keep-alive supplies / battery backup

Hardware Specifications

Power Supply Requirements

  • Battery input voltage range: 1.8 V to 5.5 V

  • Quiescent current: 100 nA

  • 8 selectable peak input current limits: 5 mA, 10 mA, 15 mA, 20 mA, 25 mA, 50 mA, 75 mA, 100 mA

No-OS Build Setup

Please see: No-OS Build Guide

No-OS Supported Examples

The initialization data used in the examples is taken out from the Project Common Data Path.

The macros used in Common Data are defined in platform specific files found in the Project Platform Configuration Path.

Basic example

The basic example initializes the LTC3337 device and continuously reads accumulated charge, battery input/output voltages (with iPeak on and off), and die temperature, printing the results over UART.

In order to build the basic example, make sure you have the following configuration in the Makefile:

# Select the example you want to enable by choosing y for enabling and n for disabling
BASIC_EXAMPLE = y

No-OS Supported Platforms

Maxim

Used Hardware

Connections

The DC2973A communicates via I2C. Connect the following pins between the DC2973A and the MAX32655 board:

DC2973A

MAX32655

SCL

I2C2 SCL

SDA

I2C2 SDA

GND

GND

Build Command

# to delete current build
make reset
# to build the project
make PLATFORM=maxim TARGET=max32655
# to flash the code
make run