BQ2407xT 系列器件是集成型锂离子线性充电器和系统电源路径管理器件,适用于空间受限的便携式 应用。该器件由 USB 端口或交流适配器供电,支持高达 1.5A 的充电电流,还具有输入过压保护功能,因此在输入电压范围内支持非稳压适配器。BQ2407xT 的 USB 输入电流限制精度和启动序列使得这款器件能够符合 USB-IF 浪涌电流规范。此外,输入动态电源管理 (VIN-DPM) 可防止充电器损毁错误配置的 USB 电源。
BQ2407xT 具有 动态电源路径管理 (DPPM) 功能,可在为系统供电的同时独立为电池充电。当输入电流限制引起系统输出降至 DPPM 阈值时,DPPM 电路将减少充电电流;因此,可在为系统负载供电时随时监测充电电流。这个特性减少了电池上充放电周期的数量,可实现充电正常终止并使得系统能够在由有缺陷或者不完整的电池组供电的情况下运行。
器件型号 | 封装 | 封装尺寸(标称值) |
---|---|---|
BQ24072T | VQFN (16) | 3.00mm x 3.00mm |
BQ24075T | ||
BQ24079T |
Changes from B Revision (November 2014) to C Revision
Changes from A Revision (April 2010) to B Revision
Changes from * Revision (December 2009) to A Revision
此外,该系列充电器可提供经稳压的系统输入,即使在电池完全放电的情况下,也可使系统在连接电源后实现瞬间开启。此电源路径管理架构还允许在适配器不能够发送峰值系统电流时补偿系统电流需求,从而使得能够使用较小的适配器。
电池充电发生于以下三个阶段:调节、恒定电流和恒定电压。在所有的充电阶段,一个内部控制环路监测 IC 结温并且如果超过此内部温度阈值则减少充电电流。充电器功率级和充电电流感应功能完全集成在了一起。该充电器具高精度电流和电压调节环路、充电状态显示和充电终止功能。输入电流限制和充电电流可使用外部电阻编程设定。
PIN | DESCRIPTION | |||
---|---|---|---|---|
NAME | NUMBER | I/O | ||
BQ24072T | BQ24075T
BQ24079T |
|||
TS | 1 | 1 | I/O | External NTC Thermistor Input. Connect the TS input to the center tap of a resistor divider from VIN to GND with the NTC in parallel with the bottom resistor to monitor the NTC in the battery pack. For applications that do not utilize the TS function, set the resistor divider to be a 20% ratio. See the Battery Pack Temperature Monitoring section for details on calculating the resistor values. |
BAT | 2, 3 | 2, 3 | I/O | Charger Power Stage Output and Battery Voltage Sense Input. Connect BAT to the positive terminal of the battery. Bypass BAT to VSS with a 4.7μF to 47μF ceramic capacitor. |
CE | 4 | 4 | I | Charge Enable Active-Low Input. Connect CE to a high logic level to place the battery charger in standby mode. In standby mode, OUT is active and battery supplement mode is available. Connect /CE to a low logic level to enable the battery charger. CE is internally pulled down with ~285kΩ. Do not leave CE unconnected to ensure proper operation. |
EN2 | 5 | 5 | I | Input Current Limit Configuration Inputs. Use EN1 and En2 to control the maximum input current and enable USB compliance. See for the description of the operation states. EN1 and EN2 are internally pulled down with ~285kΩ. Do not leave EN1 or EN2 unconnected to ensure proper operation. |
EN1 | 6 | 6 | I | |
PGOOD | 7 | 7 | O | Open-Drain Power Good Status Indication Output. PGOOD pulls to VSS when a valid input source is detected. PGOOD is high-impedance when the input power is not within specified limits. Connect PGOOD to the desired logic voltage rail using a 1kΩ to 100kΩ resistor, or use with an LED for visual indication. |
VSS | 8 | 8 | – | Ground. Connect to the thermal pad and to the ground rail of the circuit. |
CHG | 9 | 9 | O | Open-Drain Charging Status Indication Output. CHG pulls to VSS when the battery is charging. CHG is high-impedance when charging is complete or when the charger is disabled. CHG flashes to indicate a timer fault. Connect CHG to the desired logic voltage rail using a 1kΩ to 100kΩ resistor, or use with an LED for visual indication. |
OUT | 10, 11 | 10, 11 | O | System Supply Output. OUT provides a regulated output when the input is below the OVP threshold and above the regulation voltage. When the input is out of the operation range, OUT is connected to VBAT except when SYSOFF is high. Connect OUT to the system load. Bypass OUT to VSS with a 4.7μF to 47μF ceramic capacitor. |
ILIM | 12 | 12 | O | Adjustable Current Limit Programming Input. Connect a 1.07kΩ to 7.5kΩ resistor from ILIM to VSS to program the maximum input current (EN2=1, EN1=0). The input current includes the system load and the battery charge current. Leaving ILIM unconnected disables all charging. |
IN | 13 | 13 | I | Input Power Connection. Connect IN to the external DC supply (AC adapter or USB port). The input operating range is 4.35V to 6.6V. The input accepts voltages up to 26V without damage, but operation is suspended. Bypass IN to VS with a 1μF to 10μF ceramic capacitor. |
TMR | 14 | 14 | I | Timer Programming Input. TMR controls the pre-charge and fast-charge safety timers. Connect TMR to VSS to disable all safety timers. Connect a 18kΩ to 72kΩ resistor between TMR and VSS to program the timers to a desired length. Leave TMR unconnected to set the timers to the default values. |
SYSOFF | – | 15 | I | System Enable Input. Connect SYSOFF high to turn off the FET connecting the battery to the system output. When an adapter is connected, charge is also disabled. Connect SYSOFF low for normal operation. SYSOFF is internally pulled up to VBAT through a large resistor (~5MΩ). Do not leave SYSOFF unconnected to ensure proper operation. |
TD | 15 | – | I | Termination Disable Input. Connect TD high to disable charger termination. Connect TD to VSS to enable charger termination. TD is checked during startup only and cannot be changed during operation. See the TD section in this datasheet for a description of the behavior when termination is disabled. TD is internally pulled down to VSS with ~285 kΩ. Do not leave TD unconnected to ensure proper operation. |
ISET | 16 | 16 | I/O | Fast Charge Current Programming Input. Connect a 590 Ω to 3 kΩ resistor from ISET to VSS to program the fast charge current level. Charging is disabled if ISET is left unconnected. While charging, the voltage ISET reflects the actual charging current and can be used to monitor charge current. See the Charge Current Translator section of this datasheet for more details. |
Thermal Pad | – | -- | – | There is an internal electrical connection between the exposed thermal pad and the VSS pin of the device. The thermal pad must be connected to the same potential as the VSS pin on the printed circuit board. Do not use the thermal pad as the primary ground input for the device. VSS must be connected to ground at all times. |
EN2 | EN1 | MAXIMUM INPUT CURRENT INTO IN |
---|---|---|
0 | 0 | 100 mA. USB100 mode |
0 | 1 | 500 mA. USB500 mode |
1 | 0 | Set by external resistor from ILIM to VSS |
1 | 1 | Standby (USB suspend mode) |