Features

• Wide Input Voltage Range: 2.7V to 60V
• Adjustable Battery Voltage: 1.2V to 60V
• Adjustable Charge Current: 10mA to 250mA
• Low Quiescent Current While Charging: I_IN = 4μA
• Ultralow Battery Drain When Shutdown or Charged: I_BAT < 0.01μA
• Auto Recharge
• Input Voltage Regulation for High Impedance Sources
• Thermal Regulation Maximizes Output Current without Overheating
• Constant Voltage Feedback with ±0.5% Accuracy
• NTC Thermistor Input for Temperature Qualified Charging
• Adjustable Safety Timer
• Charging Status Indication
• Thermally Enhanced 10-Lead (3mm × 3mm) DFN Package

Typical Application

Description

The LTC®4079 is a low quiescent current, high voltage linear charger for most battery chemistry types including Li-Ion/Polymer, Lead-Acid or NiMH battery stacks up to 60V. The maximum charge current is adjustable from 10mA to 250mA with an external resistor. The battery charge voltage is set using an external resistor divider.

With an integrated power device, current sensing and reverse current protection, a complete charging solution using the LTC4079 requires very few external components. Thermal regulation ensures maximum charge current up to the specified limit without the risk of overheating. Charging can be terminated by either C/10 or adjustable timer.

Input voltage regulation reduces charge current when the input voltage falls to an adjustable level or the battery voltage, making it well suited for energy harvesting applications. Other features include temperature qualified charging, bad battery detection, automatic recharge with sampled feedback in standby for negligible battery drain, and an open-drain CHRG status output. The device is offered in a compact, thermally enhanced 10-lead (3mm × 3mm) DFN package.