BQ25756: BQ25756充电模块--量产中出现15%比例空载上电几秒后无电压输出

Part Number: BQ25756
Other Parts Discussed in Thread: , BQ25750, BQ25758

你们好,TI团队!麻烦协助分析原因。谢谢!

近期BQ25756充电电路,量产了40PCS,装配到充电器中。常温下 空载上电测试,发现有6pcs 无输出。重启后,3秒左右内 有电压输出(PG为打开,stat1和stat2交替 打开,表示在充电和充电完成中切换),之后无输出(PG为打开,stat1打开,stat2为关闭,表示充电中)。导致的问题是,电池插上充电器,无法进行充电。如果这些问题板卡,先接电池,再上电,就不会出现这种无输出的情况,会一直有电压输出、正常充电。

其余的85%正常板卡,空载上电后,会一直有电压输出,打嗝波形输出(PG为打开,stat1和stat2交替 打开,表示在充电和充电完成中切换)。

当前工况是,使用BQ25756芯片平台,为6串锂电池充电。输入是36V 225W的ACDC模块。

我提供下,问题板块的空载上电的几秒内的读取所有寄存器的值。这些数据是对BQ25756异常充电板卡锂电池 充电板 V1.0.0.pdf 的寄存器监测情况。监测时间是,是从板卡上电 正常输出、几秒后又进入异常情况的。寄存器的值是 从地址00读到了地址3D。
26-05-27 16:34:58.982 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0C 80 00 00 09 80 02 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:34:59.198 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0F 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:34:59.419 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:34:59.639 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:34:59.894 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:00.114 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:00.321 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0C 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:00.540 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0F 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:00.760 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:00.982 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:01.204 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:01.410 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0C 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:01.631 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0F 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:01.888 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:02.108 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:02.314 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:02.520 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:02.740 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0C 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:02.961 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 0F 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:03.182 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 01 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:03.388 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:03.594 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:03.801 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:04.007 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:04.214 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:04.431 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:04.652 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:04.894 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:05.112 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:05.320 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:05.540 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:05.746 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:05.953 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:06.160 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:06.381 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:06.587 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:06.793 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:07.000 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:07.208 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:07.414 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:07.621 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:07.895 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:08.111 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:08.318 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12
26-05-27 16:35:08.525 读成功[D6][00]: 10 00 40 06 00 00 40 06 48 03 40 06 E8 03 FF FF 40 01 A0 00 0F 1D 00 C9 C0 20 20 96 57 40 00 00 00 09 80 00 00 00 00 00 00 00 00 60 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12

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  • 您好,

    已经收到了您的案例,调查需要些时间,感谢您的耐心等待

  • 感谢!

    近期产品在小试,需要贵司协助。

  • 你好,麻烦协助分析下这个问题。谢谢!

  • 你好,麻烦协助分析下这个问题。谢谢!

  • 你好,

    对于生产线测试,我建议先将电路板连接到电池,然后再连接输入电源。BQ25756 是一个电池充电器,我不建议在输出端没有连接电池或恒压负载的情况下使用 BQ25756 的正向模式。

    如果您需要在不使用电池的情况下测试 BQ25756,我建议将 EN_TERM 和 EN_PRECHG 设置为 0。然后,您可以使用恒压负载来测试 BQ25756。

    关于你的原理图,我有几点建议:

    • 将 DRV_SUP 与 REGN 短接,使用 0Ω 电阻而不是 10Ω 电阻。
    • 我建议将C26保留为DNP(未完成护理实践)。
    • 如果 ICHG 或 ILIM_HIZ 的电阻值大于 5kΩ,我建议并联一个 RC 滤波器。
    • 仅供参考,我们提供了一份原理图和布局检查清单来帮助您: [常见问题解答] BQ25756 原理图和布局检查清单

    请您标出账簿上的任何变更并标记账簿地址?我没有看到账簿上有任何差异。

    此致,
    伊桑·加洛韦

  • 您好,很感谢回复和指导。在过去的几天中,我对当前的锂电池充电器,进行了一些调整(将EN_TERM 和 EN_PRECHG 设置为 0),并验证了多块板卡,基本测试通过。想请您帮忙审核我的调整。

    当前的应用场景:一款双通道的锂电池座充,通过内部主控芯片调整快充、慢充。平常是上电待机(也无系统供电输出),等待给锂电池充电。(应该不算是 恒压负载测试BQ25756)

    本次设计上的调整:内部主控芯片上电后,会对BQ25756芯片进行设置寄存器值,EN_TERM 和 EN_PRECHG 设置为 0,禁止充电终止和预充电功能。

    调整后的座充现象:

    1. 上电后,未接电池,状态为:PG为打开,stat1打开,stat2为打开,表示:检测到充电故障(TS 超出范围、安全计时器故障等)。充电端口电压为23.2V。
    2. 接入电池,长时间充电后,状态为:PG为打开,stat1打开,stat2为关闭,表示充电中。取下电池后,电压读取为25.15V。

     请帮忙审核一下,以上的调整和现象,是否有需要优化的地方?
    ————————————

    另外有一个问题:为什么BQ25756芯片的表现状态不一致?以初次问题里面的芯片为例。40pcs BQ25756芯片中,有85%的BQ芯片 上电后,在无电池、无系统负载的情况下,持续有打嗝电压(最高电压为设置的充电电压)的稳定输出,无需将 EN_TERM 和 EN_PRECHG 设置为 0。其他的15%的BQ芯片,在无电池、无负载上电后会有3秒左右电压输出、又进入无电压输出的状态,状态却为:PG为打开,stat1打开,stat2为关闭,表示充电中。

    芯片表现不一样的原因是什么?是跟芯片手册中的以下描述有关吗?“对于锂离子电池充电,当充电电流低于终止阈值、充电电压高于充电阈值且器件不处于DPM模式时,充电器器件自动终止充电周期。” 8.3.4.1 自主充电周期(https://www.ti.com.cn/cn/lit/ds/symlink/bq25756e.pdf?ts=1781061989845&ref_url=https%253A%252F%252Fwww.ti.com.cn%252Fproduct%252Fcn%252FBQ25756E%253Fqgpn%253Dbq25756e)

    ————————

    我从论坛的其他帖子也看到了很多要将 EN_TERM 和 EN_PRECHG 设置为 0的案例,并有推荐使用BQ25750。请问我当前的使用场景,符合BQ25750吗?

    盼望回复,谢谢!

  • 你好,

    感谢您提供关于申请的新信息。也感谢您的耐心等待。

    这是一款双通道锂电池充电器,可通过其内部主控芯片调节快充和慢充。通常情况下,开机后(无系统电源输出)充电器处于待机模式,等待为锂电池充电。(这不应被视为对 BQ25756 的恒压负载测试。)

    当 BQ25756 处于待机模式时,充电功能是启用还是禁用?

    请查看以上调整和现象。是否存在需要优化的方面?

    未连接电池时,有没有办法禁用 BQ25756?

    另一个问题:为什么 BQ25756 芯片的行为不一致?

    BQ25756 的设计目的并非在输出端没有负载时进行充电。

    我认为BQ25750不太适合您的系统。您能否考虑使用BQ25758? BQ25758是一款带有CV和CC控制回路的DC-DC转换器,可以有效地为电池充电。与BQ25756相比,BQ25758在输出空载时性能更佳。此外,BQ25758与BQ25756引脚完全相同。

    我认为使用 BQ25758 是您系统的最佳解决方案。

    此致,
    伊桑·加洛韦

  • 谢谢回复。

    BQ25756 处于待机模式时,充电功能是启用还是禁用?当前的设计是,待机时 充电功能是启用的。电池插上,就可以充电。

    未连接电池时,有没有办法禁用 BQ25756?方法是,充电器的内部控制器,通过IIC通信或者CE引脚,禁用BQ25756。(但当前的充电器上,无插入检测功能,无法知道电池何时插入)

    请问BQ25758芯片,如果应用于 当前的设计上(即充电芯片待机时,充电功能是启用),也是很符合的吗?能否解释下“BQ25758在输出空载时性能更佳”的原因是什么?

  • 你好,

    如果在当前设计中使用 BQ25758 芯片(即,充电功能在充电芯片处于待机模式时启用),是否合适?

    是的,BQ25758 在这里可以用。

    请问为什么 BQ25758 在输出端空载时性能更好?

    BQ25756 具有多种不同的控制模式,可用于给电池充电。当 BQ25756 输出端无负载时,它将处于恒流模式和恒压模式的临界状态。此外,如果输出电压超过设定电压的 104%,BQ25756 将自动关闭,以防止电池过压损坏。由于输出端连接有电池,这些控制回路通常不会造成问题。

    BQ25758 在恒压模式下运行时,其控制回路的数量较少。这意味着 BQ25758 更适合在输出端无电池或负载的情况下以恒压模式运行。

    如果您对此有任何疑问,请告诉我。

    此致,
    伊桑·加洛韦

  • 你好,

    如果在当前设计中使用 BQ25758 芯片(即,充电功能在充电芯片处于待机模式时启用),是否合适?

    是的,BQ25758 在这里可以用。

    请问为什么 BQ25758 在输出端空载时性能更好?

    BQ25756 具有多种不同的控制模式,可用于给电池充电。当 BQ25756 输出端无负载时,它将处于恒流模式和恒压模式的临界状态。此外,如果输出电压超过设定电压的 104%,BQ25756 将自动关闭,以防止电池过压损坏。由于输出端连接有电池,这些控制回路通常不会造成问题。

    BQ25758 在恒压模式下运行时,其控制回路的数量较少。这意味着 BQ25758 更适合在输出端无电池或负载的情况下以恒压模式运行。

    如果您对此有任何疑问,请告诉我。

    此致,
    伊桑·加洛韦

  • 你好,感谢回复。按照您的指导,我们作出如下改动:硬件设计不变,BQ25756和外围电路不变,座充内部MCU主机修改逻辑。在检测到有电池通信或者充电选择按键后,开启充电使能(CE引脚),持续5秒。5秒后,继续判断通信,如果与电池通信,则继续使能;如果与电池无通信,则关闭充电使能。座充待机时(无电池),关闭充电使能。此按键原先定义是 快充和慢充切换键,现在增加一个手动充电使能功能。

    使用正常电池测试没有问题。只是对于过放保护的电池,由于无法主机MCU无法通过通信检测到欠压保护的电池,仅一次按键即充电使能5s 无法激活欠压保护的锂电池,需要再次按键(2~3次按键),才能激活此锂电池。当前的锂电池为充放电分口的电池,5个引脚分别为:正极、放电负极、充电正极、通信Rx、通信Tx。6串锂电池,满充电压为25.2V,欠压保护点为16.2V,释放电压为18V。

    请帮忙审核,以上的调整和现象,是否有需要优化的地方?