LTC4020 Datasheet

• Wide Voltage Range: 4.5V to 55V Input, Up to 55V Output (60V Absolute Maximums)
• Synchronous Buck-Boost DC/DC Controller
• Li-Ion and Lead-Acid Charge Algorithms
• ±0.5% Float Voltage Accuracy
• ±5% Charge Current Accuracy
• Instant-On for Heavily Discharged Batteries
• Ideal Diode Controller Provides Low Loss PowerPath When Input Power is Limited
• Input Voltage Regulation for High Impedance Input Supplies and Solar Panel Peak Power Operation
• Onboard Timer for Protection and Termination
• Bad Battery Detection with Auto-Reset
• NTC Input for Temperature Qualified Charging
• Binary Coded Open-Collector Status Pins
• Low Profile (0.75mm) 38-Pin 5mm × 7mm QFN Package

• Portable Industrial and Medical Equipment
• Solar-Powered Systems
• Military Communications Equipment
• 12V to 24V Embedded Automotive Systems

The LTC4020 is a high voltage power manager providing PowerPath^™ instant-on operation and high efficiency battery charging over a wide voltage range. An onboard buck-boost DC/DC controller operates with battery and/or system voltages above, below, or equal to the input voltage.

The LTC4020 seamlessly manages power distribution between battery and converter outputs in response to load variations, battery charge requirements and input power supply limitations.

The LTC4020 battery charger can provide a constant-current/constant-voltage charge algorithm (CC/CV), constant-current charging (CC), or charging with an optimized 4-step, 3-stage lead-acid battery charge profile. Maximum converter and battery charge currents are resistor programmable.

The IC's instant-on operation ensures system load power even with a fully discharged battery. Additional safety features include preconditioning for heavily discharged batteries and an integrated timer for termination and protection.