This document provides an insight into the architecture and operation of LTC1325, outlines basic techniques for charging various battery types, presents a variety of useful charging circuits, and gives an overview of the battery management system's features.
The document introduces the LTC1325, a flexible battery management integrated circuit designed to charge various battery types including Nickel-Cadmium, Nickel-Metal Hydride, Sealed Lead-Acid, and Lithium-Ion. It details how an external microprocessor controls the chip's functional blocks via a serial interface to implement custom charging algorithms.
The note outlines basic techniques for multi-stage charging (Fast Charge, Top-Off, Trickle) and explains how the LTC1325 handles fault protection through monitoring of battery temperature, cell voltage, and elapsed time. It also covers the chip's capacity monitoring features known as 'Gas Gauge' mode.
| Supply Voltage Range (VDD) | 4.5V to 16V |
|---|---|
| Maximum Series Cells | 8 cells in series |
| Shutdown Current | 30 µA |
| ADC Resolution | 10-bit |
It can charge Nickel-Cadmium, Nickel-Metal Hydride, Sealed Lead-Acid, and Lithium-Ion batteries.
Communication is via a simple serial interface that can be configured for 3-wire or 4-wire operation.
The chip supports termination based on battery temperature (T BAT), cell voltage (VCELL), time (t), ambient temperature (T AMB), or combinations thereof.