TI BQ25606RGER

The bq25606 is a highly integrated, standalone 3.0A switch-mode battery charging management and system power path management device suitable for single-cell lithium-ion and lithium-polymer batteries. The low-impedance power path optimizes the efficiency of switch-mode operation, shortens the battery charging time, and extends the battery life during the discharge phase.

The bq25606 is a highly integrated, standalone 3.0A switch-mode battery charging management and system power path management device suitable for single-cell lithium-ion and lithium-polymer batteries. The device enables fast charging for various standalone chargers and portable devices and provides high input voltage support. Its low-impedance power path optimizes the efficiency of switch-mode operation, shortens the battery charging time, and extends the battery life during the discharge phase. Its input voltage and current regulation can provide maximum charging power for the battery.

This solution highly integrates an input reverse-blocking field FET (RBFET, Q1), a high-side switch FET (HSFET, Q2), a low-side switch FET (LSFET, Q3), and a battery FET (BATFET, Q4) between the system and the battery. It also integrates a bootstrap diode for high-side gate drive, thus simplifying the system design.

The device supports multiple input sources, including standard USB host ports, USB charging ports, and USB-compatible high-voltage adapters. The device sets the default input current limit according to the built-in USB interface. The device complies with USB 2.0 and USB 3.0 power specifications and has input current and voltage regulation functions. When the built-in USB interface of the device determines that the input adapter is unknown, the input current limit of the device is determined by the resistor value set on the ILIM pin.

The device also has a constant current limiting capability of up to 1.2A and can provide a voltage of 5.15V for VBUS, complying with the USB On-the-Go (OTG) operating power rating specification. The power path management regulates the system voltage to a level slightly higher than the battery voltage but does not drop below the minimum system voltage of 3.5V. With this feature, the system can keep running even when the battery is completely depleted or removed. When the input current limit or voltage limit is reached, the power path management automatically reduces the charging current to 0. As the system load continues to increase, the power path discharges the battery before meeting the system power demand. This supplementary mode prevents the input source from being overloaded.

This device starts and completes a charging cycle without software control. It senses the battery voltage and charges the battery through three stages: pre-charging, constant current, and constant voltage. At the end of the charging cycle, when the charging current is below the preset limit and the battery voltage is above the recharge threshold, the charger automatically terminates. If the fully charged battery drops below the recharge threshold, the charger automatically starts another charging cycle.

This charger provides multiple safety functions for battery charging and system operation, including battery negative temperature coefficient thermistor monitoring, charging safety timer, and overvoltage and overcurrent protection. When the junction temperature exceeds 110°C, thermal regulation reduces the charging current. The STAT output reports the charging status and any fault conditions. Other safety functions include battery temperature sensing for charging and boost modes, thermal regulation and thermal shutdown, and input UVLO and overvoltage protection.

• High-efficiency 1.5MHz synchronous switch-mode buck charger with 92% charging efficiency at 2A (5V input), optimized for USB voltage input (5V)
• USB On-The-Go (OTG) support
• Boost converter with up to 1.2A output and 92% boost efficiency at 1A output
• Accurate constant current (CC) limiting
• Soft-start for capacitive loads up to 500μF
• Output short-circuit protection
• Single input supporting USB input and high-voltage adapter
• 3.9V to 13.5V input voltage range with 22V absolute maximum input voltage rating
• Maximum power tracking via input voltage limit (VINDPM) up to 4.6V
• VINDPM threshold auto-tracks battery voltage
• Auto-detection of USB SDP, DCP, and non-standard adapters
• High battery discharge efficiency with 19.5mΩ battery discharge MOSFET
• Narrow VDC (NVDC) power path management
• Instant-on operation without battery or with deeply discharged battery
• Ideal diode operation in battery charging mode
• High integration including all MOSFETs, current sensing, and loop compensation
• 58μA low battery leakage current at system standby voltage
• High accuracy
• ±0.5% charge voltage regulation
• ±6% charge current regulation at 1.2A and 1.8A
• ±5% input current regulation at 0.5A, 1.2A, and 1.8A
• Create custom designs using bq25606 with WEBENCH Power Designer

• EPOS
• Portable speakers
• E-cigarettes
• Portable internet devices and accessories