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Cost-Saving, Multichemistry, Battery Charger System

Universal Charger with Low-Cost µC or Stand-Alone Li+ Charger

Product Details

Key Features

Parametric specs for Battery Chargers
Charging VIN (V) (max) 20
Max. ICHG (A) 2
Cell Chemistry Li-Ion
Li-Polymer
NiCd
NiMH
# NiMH/ NiCd Cells 1
2
3
4
5
6
7
8
9
10
11
# Lithium Ion Cells 1
2
Protected VIN (V) (max) 20
Charger (V) 18
Oper. Temp. (°C) -40 to +85
Package/Pins QSOP/16
Budgetary
Price (See Notes)
3.7
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Simplified Block Diagram

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Parameters

Parametric specs for Battery Chargers
Charging VIN (V) (max) 20
Max. ICHG (A) 2
Cell Chemistry Li-Ion
Li-Polymer
NiCd
NiMH
# NiMH/ NiCd Cells 1
2
3
4
5
6
7
8
9
10
11
# Lithium Ion Cells 1
2
Protected VIN (V) (max) 20
Charger (V) 18
Oper. Temp. (°C) -40 to +85
Package/Pins QSOP/16
Budgetary
Price (See Notes)
3.7

Key Features

  • Multichemistry Charger System (Li-Ion, NiMH, NiCd)
  • Independent Voltage and Current Loops
  • ±0.5% Internal Reference for Li-Ion Cells
  • Lowers Cost:
    • Stands Alone or Uses Low-Cost µC
    • Built-In 1% Linear Regulator Powers µC
    • Linear Regulator Provides Reference to µC ADCs
    • Built-In µC Reset
    • Controls Low-Cost External PNP Transistor or P-Channel MOSFET
  • Space-Saving 16-Pin QSOP
  • Charging-Current-Monitor Output
  • < 1µA Battery Drain when Off

Applications/Uses

  • Cell Phones
  • Desktop Cradle Chargers
  • Handheld Instruments (PDAs, Palmtops)
  • Li+ Battery Packs
  • Li+-Ion/NiMH/NiCd Multichemistry Battery Chargers
  • Notebook Computers

Description

The MAX846A is a cost-saving multichemistry battery-charger system that comes in a space-saving 16-pin QSOP. This integrated system allows different battery chemistries (Li-Ion, NiMH or NiCd cells) to be charged using one circuit.

In its simplest application, the MAX846A is a stand-alone, current-limited float voltage source that charges Li-Ion cells. It can also be paired up with a low-cost microcontroller (µC) to build a universal charger capable of charging Li-Ion, NiMH, and NiCd cells.

An internal 0.5%-accurate reference allows safe charging of Li-Ion cells that require tight voltage accuracy. The voltage- and current-regulation loops used to control a low-cost external PNP transistor (or P-channel MOSFET) are independent of each other, allowing more flexibility in the charging algorithms.

The MAX846A has a built-in 1%, 3.3V, 20mA linear regulator capable of powering the µC and providing a reference for the µC's analog-to-digital converters. An on-board reset notifies the controller upon any unexpected loss of power. The µC can be inexpensive, since its only functions are to monitor the voltage and current and to change the charging algorithms.

Simplified Block Diagram

MAX846A: Typical Operating Circuit MAX846A: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .