Power Management Battery Management Coulomb Counter (Battery Fuel Gauge)

LTC1325 - Microprocessor-Controlled Battery Management System

Features

  • Fast Charge Nickel-Cadmium, Nickel-Metal-Hydride, Lithium Ion or Lead-Acid Batteries under µP Control
  • Flexible Current Regulation:
    - Programmable 111kHz PWM Current Regulator with Built-In PFET Driver
    - PFET Current Gating
  • Discharge Mode
  • Measures Battery Voltage, Battery Temperature and Ambient Temperature with Internal 10-Bit ADC
  • Battery Voltage, Temperature and Charge Time Fault Protection
  • Built-In Voltage Regulator and Programmable Battery Attenuator
  • Easy-to-Use 3- or 4-Wire Serial µP Interface
  • Accurate Gas Gauge Function
  • Wide Supply Range: VDD = 4.5V to 16V
  • Can Charge Batteries with Voltages Greater Than VDD
  • Can Charge Batteries from Charging Supplies Greater Than VDD
  • Digital Input Pins Are High Impedance in Shutdown Mode

Typical Application

LTC1325 Typical Application

Description

The LTC1325 provides the core of a flexible, cost-effective solution for an integrated battery management system. The monolithic CMOS chip controls the fast charging of nickel-cadmium, nickel-metal-hydride, lead-acid or lithium batteries under microprocessor control. The device features a programmable 111kHz PWM constant current source controller with built-in FET driver, 10-bit ADC, internal voltage regulator, discharge-before-charge controller, programmable battery voltage attenuator and an easy-to-use serial interface.

The chip may operate in one of five modes: power shut-down, idle, discharge, charge or gas gauge. In power shutdown the supply current drops to 30µA and in the idle mode,an ADC reading maybe made withou tany switching noise affecting the accuracy of the measurement. In the discharge mode, the battery is discharged by an external transistor while the battery is being monitored by the LTC1325 for fault conditions. The charge mode is terminated by the µP while monitoring any combination of battery voltage and temperature, ambient temperature and charge time. The LTC1325 also monitors the battery for fault conditions before and during charging. In the gas gauge mode the LTC1325 allows the total charge leaving the battery to be calculated.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing		 RoHS
LTC1325CN#PBF N-18 N C 05-08-1510 (N18) Yes
LTC1325CSW#PBF SW-18 SW C 05-08-1620 (SW18) Yes
LTC1325CSW#TRPBF SW-18 SW C 05-08-1620 (SW18) Yes


LTC1325 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)		 Price
(1k)*		 RoHS
LTC1325CN#PBF N-18 C $9.15 $7.25 Yes
LTC1325CSW#PBF SW-18 C $9.15 $7.25 Yes
LTC1325CSW#TRPBF SW-18 C $7.35 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Applications

  • System Integrated Battery Charger

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