TI BQ24133RGYR

The bq24133 is highly integrated stand-alone Li-ion and Li-polymer switch-mode battery charger with two integrated N-channel power MOSFETs. It offers a constant-frequency synchronous PWM controller with high accuracy regulation of input current, charge current, and voltage. It closely monitors the battery pack temperature to allow charge only in a preset temperature window. It also provides battery detection, pre-conditioning, charge termination, and charge status monitoring. The thermal regulation loop reduces charge current to maintain the junction temperature of 120°0 during operation. The bq24133 charges a one, two, or three cell Li-Ion battery in three phases: precondictioning, constant current, and constant voltage. Charge is terminated when the current reaches 10% of the fast charge rate. A programmable charge timer offers a safety back up. The bq24133 automatically restarts the charge cycle if the battery voltage falls below an internal threshold, and enters a low-quiescent current sleep mode when the input voltage falls below the battery voltage. The bq24133 features Dynamic Power Management (DPM) to reduce the charge current when the input power limit is reached to avoid over-loading the adapter. A highly-accurate current-sense amplifier enables precise measurement of input current from adapter to monitor overall system power. The bq24133 provides power path selector gate driver ACDRV/CMSRC on input NMOS pair ACFET (Q1) and RBFET (Q2), and BATDRV on a battery PMOS device (Q3). When the qualified adapter is present, the system is directly connected to the adapter. Otherwise, the system is connected to the battery. In addition, the power path prevents battery from boosting back to the input. The bq24170/172 charges the battery from a DC source as high as 17V, including a car battery. The input over-voltage limit is adjustable through the OVPSET pin. The AVCC, ACP, and ACN pins have a 30V rating. When a high voltage DC source is inserted, Q1/Q2 remain off to avoid high voltage damage to the system. For 1 cell applications, if the battery is not removable, the system can be directly connected to the battery to simplify the power path design and lower the cost. With this configuration, the battery can automatically supplement the system load if the adapter is overloaded. bq24133 is available in a 24-pin, 3.5mm × 5.5mm thin QFN pack

• 1.6MHz Synchronous Switch-Mode Charger with 2.5A Integrated N-MOSFETs
• Up to 92% Efficiency
• 30V Input Rating with Adjustable Over-Voltage Protection
• 4.5V to 17V Input Operating Voltage
• Battery Charge Voltage: 1, 2, or 3-Cell with 4.2V/Cell
• Automatic Power Path Selector Between Adapter and Battery
• Dynamic Power Management
• Integrated 20-V Switching MOSFETs
• Integrated Bootstrap Diode
• Internal Loop Compensation
• Internal Digital Soft Start
• Thermal Regulation Loop Throttles Back Current to Limit Tj = 120°C
• Thermal Shutdown
• Battery Thermistor Sense Hot/Cold Charge Suspend & Battery Detect
• Input Over-Voltage Protection with Programmable Threshold
• Cycle-by-Cycle Current Limit
• ±0.5% Charge Voltage Regulation ±5% Charge Current Regulation ±6% Input Current Regulation
• Less than 15μΔ Battery Current with Adapter Removed
• Less than 1.5mA Input Current with Adapter Present and Charge Disabled
• Small QFN Package: 3.5mm × 5.5mm QFN-24 Pin

• Tablet PC
• Netbook and Ultra-Mobile Computers
• Portable Data Capture Terminals
• Portable Printers
• Medical Diagnostics Equipment
• Battery Bay Chargers
• Battery Back-Up Systems