Features

li-agit or Li-POL cost management and single-chip synchronization DC-DC power converter to power the Bluetooth and optimize #8482; headphones and accessories

[123 ] USB through AC adapters or the selection of autonomous power supply to the system charging and power supply

Integrated USB charging control

500 mAh charging ratio

Integrated power field effect tube and current sensor

up to 500 mAh charging applications and

#8226 ; Bringing 100mao DC-DC controller with FET

Reverse leakage protection to prevent battery discharge

123] Low -current or compulsory pulse width adjustment efficiency in frequent applications

3.5 mm × 4.5 mm QFN packaging

Application

#8226; Bluetooth #8482; Headphones

Bluetooth #8482; Accessories

Low -power handheld equipment

Instructions

The BQ2501X series is a highly integrated charging and power management equipment for Bluetooth applications with limited space. The BQ2501X series provides integrated power field effect pipes and current sensors for charging control, reverse atresia protection, high-precision current and voltage adjustment, charging status, charging terminal connection, and a small high-efficiency and low power DC-DC converter.

BQ2501X battery charging is divided into three stages: adjustment, constant current and constant voltage. Terminal charging according to the minimum current. The internal charging timer provides spare safety functions for charging. If the battery voltage is lower than the internal threshold, the BQ2501X will automatically start charging. When the VCC power is disconnected, the BQ2501X automatically enters the dormant mode.

Integrated low-power and high-efficiency DC-DC converters designed to work directly from single battery lithium ions or lithium polarized battery packs. The output voltage can be adjusted from 0.7 V to VBAT (

BQ25010

), fixed at 3.3 V (

BQ25011 ), or fixed at 1.8 v ( bq25012 )), and can be able Provide a load current of up to 150 mAh. The DC-DC converter allows the use of small sensors in synchronous 1 MMS switch.

Please note that the availability and standard guarantee of Texas instrument semiconductor productsAnd the use in key applications and the important notice of the exemption statement appear at the end of this data table.

Typical operating characteristics

Figure Figure

function description

[[[

123] Battery charger

BQ2501X supports precision lithium ions or lithium polarized charging systems suitable for single battery packs, as well as low-power DC-DC converters used to power the system processor. Typical charge distribution, application circuit and operation flowcharts are shown in Figure 3 to Figure 5, respectively.

Selection of the autonomous power supply By default, BQ2501X tries to charge the battery by exchange input. If the communication input does not exist, select USB input. If both inputs are available, the AC adapter has priority. See Figure 6 for details.

Battery pre -adjustment

During the charging cycle, if the battery voltage is lower than the V (low voltage) threshold, the BQ2501X will apply the battery to the battery (Pre -mercury pillar). This feature resurrected deeply discharged cells. The resistor RSET connected between Iset1 and VSS pins determines the pre -charging rate. V (prechg) and K (set) parameters are specified in the specification table.

BQ2501X starts a safe timer T (Prechg) during the adjustment phase. If the V (low V) threshold is not reached during the timer cycle, the BQ2501X is off the charger, and a fault signal is issued on the STAT1 and STAT2 pin. For more details, see the timer failure recovery part.

Battery charging current

BQ2501X provides in -table current adjustment with programmable settings. The resistor RSET connected between Iset1 and VSS pin determines the charging ratio. V (set) and K (set) parameters are specified in the specification table.

When charging from the USB port, the host controller can use the ISET2 pin to select 100mAh or 500 mAh charging ratio. The low level signal sets the current to 100 mAh, and the high level signal sets the current to 500 mAh. High Z input disable USB charging.

Battery voltage adjustment

Voltage adjustment feedback through BAT/OUT pins. This input is directly connected to the positive electrode of the battery pack. BQ2501X monitor battery pack voltage between BAT/OUT and VSS pin. When the battery voltage rises to the VO (REG) threshold, the voltage adjustment stage begins, and the charging current begins to gradually decrease.

As a security backup, BQ2501X also monitor the charging time in the charging mode. If the taper threshold is not detected in this period of T (CHG), the BQ2501X off the charger and announce the failure on the STAT1 and STAT2 pin. For more details, see the timer failure recovery " section.

Charging cone detection