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Advanced Chemistry-Independent, Level 2 Battery Charger with Input Current Limiting

Product Details

Key Features

Parametric specs for Battery Chargers
Charging VIN (V) (max) 28
Max. ICHG (A) 3
Cell Chemistry Lead Acid
Li-Ion
Li-Polymer
NiCd
NiMH
Universal
# NiMH/ NiCd Cells 1
2
3
4
5
6
7
8
# Lithium Ion Cells 2
3
4
Protected VIN (V) (max) 28
Charger (V) 1 to 18.4
Oper. Temp. (°C) -40 to +85
Package/Pins QSOP/28
Budgetary
Price (See Notes)
0
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Simplified Block Diagram

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Parameters

Parametric specs for Battery Chargers
Charging VIN (V) (max) 28
Max. ICHG (A) 3
Cell Chemistry Lead Acid
Li-Ion
Li-Polymer
NiCd
NiMH
Universal
# NiMH/ NiCd Cells 1
2
3
4
5
6
7
8
# Lithium Ion Cells 2
3
4
Protected VIN (V) (max) 28
Charger (V) 1 to 18.4
Oper. Temp. (°C) -40 to +85
Package/Pins QSOP/28
Budgetary
Price (See Notes)
0

Key Features

  • Input Current Limiting
  • 175s Charge Safety Timeout
  • 128mA Wake-Up Charge
  • Charges Any Chemistry Battery: Li+, NiCd, NiMH, Lead Acid, etc.
  • Intel SMBus 2-Wire Serial Interface
  • Compliant with Level 2 Smart Battery Charger Spec Rev 1.0
  • +8V to +28V Input Voltage Range
  • Up to 18.4V Battery Voltage
  • 11-Bit Battery Voltage Setting
  • ±0.8% Output Voltage Accuracy with Internal Reference
  • 3A (max) Battery Charge Current
  • 6-Bit Charge-Current Setting
  • 99.99% (max) Duty Cycle for Low-Dropout Operation
  • Load/Source Switchover Drivers
  • >97% Efficiency

Applications/Uses

  • Notebook Computers
  • Personal Digital Assistants
  • Point-of-Sale Terminals

Description

The MAX1645B is a high-efficiency battery charger capable of charging batteries of any chemistry type. It uses the Intel System Management Bus (SMBus™) to control voltage and current-charge outputs.

When charging lithium-ion (Li+) batteries, the MAX1645B automatically transitions from regulating current to regulating voltage. The MAX1645B can also limit line input current so as not to exceed a predetermined current drawn from the DC source. A 175s charge safety timer prevents "runaway charging" should the MAX1645B stop receiving charging voltage/current commands.

The MAX1645B employs a next-generation synchronous buck control circuitry that lowers the minimum input-to-output voltage drop by allowing the duty cycle to exceed 99%. The MAX1645B can easily charge one to four series Li+ cells.

Simplified Block Diagram

MAX1645B: Typical Operating Circuit MAX1645B: 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 .