最近在用BQ24195做项目,发现如下问题;
1、在升压模式工作切换到充电模式后,STAT指示灯亮起,但是不能立马进入充电状态(电池端电流表无充电电流);
表现如下:CEpin 一直是拉低的状态,然后检测OTG被硬件拉低后关闭BOOST模式,使能CHARG BAT模式,这时候电池无充电电流;但是此时如果拔掉电池再插上或者单片机重启后(单片机启动过程中执行了初始化代码)就可以立即进入充电状态(电池端电流表出现充电电流);
2、在数据手册种看到使能充电条件如下:
A new charge cycle starts when the following conditions are valid:
• Converter starts
• Battery charging is enabled by I2C register bit (REG01[5:4]) = 01 and CE is low
• No thermistor fault on TS1 and TS2
• No safety timer fault
• BATFET is not forced to turn off (REG07[5])
其中条件2 3 4 5均以满足,但是不清楚条件1如何启动?请求TI技术解答,谢谢!
以下是BQ24195初始化代码:
/* Set REG00 EN_HIZ = Disable; VINDPM = 4.2V; IINLIM = 3A */
BQ24195_Write_Register(0x00, 0x27); // 0 0 1 0 0 1 1 1
/* Set REG04 VREG = 4.2V; BATLOWV = 3.0V; VRECHG = 100mV */
BQ24195_Write_Register(0x04, 0xB2); // 1 0 1 1 0 0 1 0
/* Set REG02 ICHG = 2.048A; Reserved = 0; FORCE_20PCT = 0 */
BQ24195_Write_Register(0x02, 0x60); // 0 1 1 0 0 0 0 0
/* Set REG05 EN_TERM = 1; TERM_STAT = 0; WATCHDOG = Disable; EN_TIMER = Enable; CHG_TIMER = 5hours; Reserved = 0 */
BQ24195_Write_Register(0x05, 0x88); // 1 0 0 0 1 0 0 0
/* Set REG01 REGISTER RESET = 0; WATCHDOG TIMER RESET = 0; CHG_CONFIG = CHARGE BAT; SYS_MIN = 3.5V; Reserved = 0 */
BQ24195_Write_Register(0x01, 0x1B); // 0 0 0 1 1 0 1 1