• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 348 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ4050: CHG Mosfets cannot be manually turned ON when VBAT > 16V and DSG FET is OFF

Darren DeBattista1
Intellectual 525 points
Part Number: BQ4050


Tool/software:

Hi, 

As the title says, I'm using a bq4050 for a 4S BMS application. The circuit is basically a copy of the application example shown on the datasheet. During testing, we need to manually turn ON/OFF the charge and discharge FETs. We realized that, when in manual mode (FETEN=0), the discharge FET is off and VBAT > 16V, the charge FET cannot be manually turned ON. When sending the command 0x001F, the bq4050 acknowledges the command and changes the internal flags to show that the charge FET is ON (CHGEN = 1) but in reality, the charge FET remains physically off. 

Is this a bug in the bq4050 IC? Will this effect the safety feature of the BMS (ex, re-enabling charging after it was disable for safety). 

Note: 

1. While in the condition where the flags are showing the charge FET is on (CHGEN=1) but in reality it is physically off, if we enable the discharge FET (mac command = 0x0020), the charge FET does than physically turn ON. 

2. Turning OFF the CHG FET always works in any condition. 

  • 0
    TI__Mastermind 37981 points

    Hello,

    Can you send a log file showing this behavior? I will need to check the other registers to see exactly what is going on.

    Regards,

    Adrian 

  • 0 in reply to Adrian
    Intellectual 525 points

    Hi, 

    Thank you for your reply. Find attached the log file. As can be seen from the log, this is the sequence we did:

    1) FET_EN = 1
    device charging

    2) FET_EN = 0
    device stopped charging

    3) set 0x001F, CHG_TEST=1
    device does not start charging

    4) set 0x0020, DSG_TEST=1
    device started charging

    5) set 0x0020, DSG_TEST=0
    device continued charging

    6) set 0x001F, CHG_TEST=0
    device stopped charging

    Fullscreen 3364.bq4050_chgfet_problem_2024-12.log Download 
    Sample,DateTime,ElapsedTime,ManufAccess,RemCapAlarm,RemTimeAlarm,BattMode,@Rate(@),@TimeFull,@TimeEmpty,@RateOK,Temperature,Voltage,Current,AvgCurr,MaxErr,RSOC,ASOC,SOH,RemCap,FullChgCap,RunTimeEmty,RunTimeEmty,AvgTimeFull,ChgCurr,ChgVolt,BattStat,CycleCnt,OpStatA,OpStatB,TempRange,ChgStat,GaugeStat,MfgStat,SafetyAlertAB,SafetyStatAB,SafetyAlertCD,SafetyStatCD,PFAlertAB,PFStatAB,PFAlertCD,PFStatCD,CellVolt1,CellVolt2,CellVolt3,CellVolt4,vBAT,vPACK,CellCurr1,CellCurr2,CellCurr3,CellCurr4,CellPower1,CellPower2,CellPower3,CellPower4,Power,AvgPow,IntTemp,TS1Temp,TS2Temp,TS3Temp,TS4Temp,CellTemp,FETTemp,CEDV_RC,DSGCap,CEDVThr,CEDVFltV,ChgDeficit,LogRowTime(ms),LogStatus
1,2024-12-03 09:22:45,1.327,0x0187,7600,10,0xE000,0,65535,65535,1,16.0,16460,1846,1650,100,78,59,75,253640,327670,65535,65535,495,4000,16800,0x0080,10,0x0187,0x0000,0x04,0x8008,0x10,0x0250,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4117,4112,4113,4119,16409,16563,1828,1831,1839,1827,753,753,756,753,3017,2734,14.3,16.0,197.1,197.1,196.3,16.0,-273.2,17181,0,0,0,0,2051,SUCCESS
2,2024-12-03 09:22:48,4.046,0x0187,7600,10,0xE000,0,65535,65535,1,16.0,16461,1820,1673,100,78,59,75,253660,327670,65535,65535,486,4000,16800,0x0080,10,0x0187,0x0000,0x04,0x8008,0x10,0x0250,,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4081,4079,4077,4077,16407,16592,450,458,451,454,184,187,184,185,2250,2734,14.4,16.1,196.8,196.3,195.7,16.1,-273.2,17183,0,0,0,0,2266,ERROR
3,2024-12-03 09:22:51,6.810,0x6181,7600,10,0xE000,0,65535,65535,1,16.0,16225,0,1552,100,78,59,75,253670,327670,65535,65535,523,0,0,0x0080,10,0x6181,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4054,4055,4055,4054,16168,16619,0,0,0,0,0,0,0,0,0,2383,14.3,16.0,197.1,197.1,197.1,16.0,-273.2,17183,0,0,0,0,2195,SUCCESS
4,2024-12-03 09:22:53,9.111,0x6181,7600,10,0xE000,0,65535,65535,1,16.1,16213,0,1353,100,78,59,75,253670,327670,65535,65535,630,0,0,0x0080,10,0x6181,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4051,4053,4053,4052,16161,16619,0,0,0,0,0,0,0,0,0,1939,14.3,16.1,196.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,1997,SUCCESS
5,2024-12-03 09:22:55,11.717,0x6181,7600,10,0xE000,0,65535,65535,1,16.1,16206,0,1101,100,78,59,75,253670,327670,65535,65535,718,0,0,0x0080,10,0x6181,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4050,4051,4052,4050,16152,16617,0,0,0,0,0,0,0,0,0,1690,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2129,SUCCESS
6,2024-12-03 09:22:58,14.464,0x6181,7600,10,0xE000,0,65535,65535,1,16.1,16200,0,896,100,78,59,75,253670,327670,65535,65535,869,0,0,0x0080,10,0x6181,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4048,4050,4050,4049,16147,16619,0,0,0,0,0,0,0,0,0,1375,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2057,SUCCESS
7,2024-12-03 09:23:00,16.591,0x6181,7600,10,0xE000,0,65535,65535,1,16.1,16195,0,781,100,78,59,75,253670,327670,65535,65535,995,0,0,0x0080,10,0x6181,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4047,4049,4049,4047,16144,16620,0,0,0,0,0,0,0,0,0,1199,14.3,16.1,197.1,195.7,197.1,16.1,-273.2,17183,0,0,0,0,2222,SUCCESS
8,2024-12-03 09:23:03,19.325,0x2185,7600,10,0xE000,0,65535,65535,1,16.1,16191,0,635,100,78,59,75,253670,327670,65535,65535,1221,4000,16800,0x0080,10,0x2185,0x0000,0x04,0x0008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4046,4048,4048,4047,16139,16618,0,0,0,0,0,0,0,0,0,975,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2167,SUCCESS
9,2024-12-03 09:23:05,21.568,0x2185,7600,10,0xE000,0,65535,65535,1,16.1,16188,0,554,100,78,59,75,253670,327670,65535,65535,1397,4000,16800,0x0080,10,0x2185,0x0000,0x04,0x0008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4046,4047,4047,4046,16136,16619,0,0,0,0,0,0,0,0,0,850,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2196,SUCCESS
10,2024-12-03 09:23:08,24.245,0x2185,7600,10,0xE000,0,65535,65535,1,16.1,16184,0,451,100,78,59,75,253670,327670,65535,65535,1714,4000,16800,0x0080,10,0x2185,0x0000,0x04,0x0008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4045,4047,4047,4045,16135,16618,-3,-10,-3,-4,-1,-4,-1,-2,5,692,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2235,SUCCESS
11,2024-12-03 09:23:11,26.967,0x2185,7600,10,0xE000,0,65535,65535,1,16.1,16181,0,393,100,78,59,75,253670,327670,65535,65535,2106,4000,16800,0x0080,10,0x2185,0x0000,0x04,0x0008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4044,4046,4046,4044,16130,16618,0,0,0,0,0,0,0,0,0,603,14.3,16.1,197.2,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2203,SUCCESS
12,2024-12-03 09:23:13,29.244,0x2185,7600,10,0xE000,0,65535,65535,1,16.1,16179,0,320,100,78,59,75,253670,327670,65535,65535,2416,4000,16800,0x0080,10,0x2185,0x0000,0x04,0x0008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4044,4056,4090,4097,16127,16619,-6,500,1835,1788,-2,203,751,733,690,491,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17183,0,0,0,0,2320,SUCCESS
13,2024-12-03 09:23:16,32.090,0x0187,7600,10,0xE000,0,65535,65535,1,16.1,16451,2094,524,100,78,59,75,253680,327670,65535,65535,1476,4000,16800,0x0080,10,0x01C7,0x0000,0x04,0x8008,0x10,0x0246,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4115,4110,4110,4117,16399,16559,2038,2029,2028,2028,839,834,834,835,3355,1028,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17185,0,0,0,0,2212,SUCCESS
14,2024-12-03 09:23:19,34.809,0x01C7,7600,10,0xE000,0,65535,65535,1,16.1,16454,1993,716,100,78,59,75,253760,327670,65535,65535,971,4000,16800,0x0080,10,0x01C7,0x0000,0x04,0x8008,0x10,0x0246,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4116,4111,4111,4118,16404,16561,1952,1950,1954,1964,803,802,803,809,3224,1317,14.3,16.1,197.1,197.1,195.7,16.1,-273.2,17186,0,0,0,0,2185,SUCCESS
15,2024-12-03 09:23:21,37.068,0x01C7,7600,10,0xE000,0,65535,65535,1,16.1,16456,1938,877,100,78,59,75,253840,327670,65535,65535,823,4000,16800,0x0080,10,0x01C7,0x0000,0x04,0x8008,0x10,0x0246,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4116,4111,4112,4118,16404,16562,1911,1913,1915,1920,787,786,787,791,3158,1558,14.3,16.1,197.1,197.1,195.7,16.1,-273.2,17187,0,0,0,0,2163,SUCCESS
16,2024-12-03 09:23:23,39.748,0x01C7,7600,10,0xE000,0,65535,65535,1,16.1,16459,1888,1070,100,78,59,75,253920,327670,65535,65535,703,4000,16800,0x0080,10,0x01C7,0x0000,0x04,0x8008,0x10,0x0246,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4116,4112,4112,4119,16405,16564,1857,1862,1870,1868,764,766,769,769,3071,1849,14.4,16.1,196.3,197.1,197.1,16.1,-273.2,17189,0,0,0,0,2279,SUCCESS
17,2024-12-03 09:23:26,42.561,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16460,1846,1218,100,78,59,75,254000,327670,65535,65535,651,4000,16800,0x0080,10,0x21C7,0x0000,0x04,0x8008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4117,4112,4113,4119,16407,16565,1827,1826,1829,1820,752,751,752,750,3012,2072,14.4,16.1,197.1,196.0,197.1,16.1,-273.2,17190,0,0,0,0,2247,SUCCESS
18,2024-12-03 09:23:29,44.894,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16461,1817,1296,100,78,59,75,254070,327670,65535,65535,614,4000,16800,0x0080,10,0x21C7,0x0000,0x04,0x8008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4117,4113,4113,4119,16409,16564,1799,1809,1803,1799,741,744,742,741,2970,2190,14.4,16.1,197.1,197.1,196.0,16.1,-273.2,17191,0,0,0,0,2226,SUCCESS
19,2024-12-03 09:23:31,47.603,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16462,1787,1390,100,78,59,75,254160,327670,65535,65535,574,4000,16800,0x0080,10,0x21C7,0x0000,0x04,0x8008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4117,4113,4113,4119,16409,16564,1776,1768,1770,1769,731,727,728,729,2920,2330,14.4,16.1,196.7,197.1,197.1,16.1,-273.2,17193,0,0,0,0,2236,SUCCESS
20,2024-12-03 09:23:34,50.357,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16463,1759,1461,100,78,59,75,254260,327670,65535,65535,547,4000,16800,0x0080,10,0x21C7,0x0000,0x04,0x8008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4118,4113,4114,4120,16410,16567,1749,1744,1746,1744,720,717,718,719,2876,2436,14.3,16.1,196.8,197.1,195.9,16.1,-273.2,17194,0,0,0,0,2234,SUCCESS
21,2024-12-03 09:23:36,52.670,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16464,1739,1497,100,78,59,75,254330,327670,65535,65535,535,4000,16800,0x0080,10,0x21C7,0x0000,0x04,0x8008,0x10,0x0242,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4118,4113,4114,4120,16412,16567,1729,1716,1726,1730,712,706,710,713,2847,2490,14.4,16.1,195.9,197.1,197.1,16.1,-273.2,17195,0,0,0,0,2195,SUCCESS
22,2024-12-03 09:23:39,55.343,0x21C7,7600,10,0xE000,0,65535,65535,1,16.1,16464,1716,1539,100,78,59,75,254420,327670,65535,65535,526,4000,16800,0x0080,10,0x21C1,0x0000,0x04,0x8008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4066,4067,4067,4066,16206,16606,104,101,107,101,42,41,44,41,1069,2483,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17196,0,0,0,0,2243,SUCCESS
23,2024-12-03 09:23:41,57.687,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16242,3,1409,100,78,59,75,254450,327670,65535,65535,566,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4058,4059,4060,4058,16183,16619,0,0,0,0,0,0,0,0,0,2164,14.4,16.1,197.1,197.0,196.7,16.1,-273.2,17196,0,0,0,0,2127,SUCCESS
24,2024-12-03 09:23:44,60.358,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16229,0,1147,100,78,59,75,254450,327670,65535,65535,688,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4056,4057,4057,4056,16177,16619,0,0,0,0,0,0,0,0,0,1761,14.4,16.1,197.1,196.4,196.8,16.1,-273.2,17196,0,0,0,0,1961,SUCCESS
25,2024-12-03 09:23:47,62.964,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16222,0,999,100,78,59,75,254450,327670,65535,65535,832,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4054,4055,4056,4054,16168,16618,-4,-5,-1,-8,-2,-2,0,-3,5,1535,14.4,16.1,196.1,197.1,197.1,16.1,-273.2,17196,0,0,0,0,2047,SUCCESS
26,2024-12-03 09:23:49,65.226,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16217,0,813,100,78,59,75,254450,327670,65535,65535,953,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4053,4054,4054,4053,16163,16621,0,0,0,0,0,0,0,0,0,1249,14.3,16.1,197.1,197.1,197.1,16.1,-273.2,17196,0,0,0,0,1991,SUCCESS
27,2024-12-03 09:23:51,67.718,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16211,0,709,100,78,59,75,254450,327670,65535,65535,1090,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4052,4053,4054,4052,16160,16619,0,0,0,0,0,0,0,0,0,1089,14.4,16.1,197.1,197.1,197.0,16.1,-273.2,17196,0,0,0,0,2119,SUCCESS
28,2024-12-03 09:23:54,69.929,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16208,0,618,100,78,59,75,254450,327670,65535,65535,1336,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4051,4052,4053,4051,16156,16620,0,0,0,0,0,0,0,0,0,949,14.4,16.1,197.1,197.1,197.1,16.1,-273.2,17196,0,0,0,0,2115,SUCCESS
29,2024-12-03 09:23:57,73.417,0x61C1,7600,10,0xE000,0,65535,65535,1,16.1,16203,0,469,100,78,59,75,254450,327670,65535,65535,1641,0,0,0x0080,10,0x61C1,0x0000,0x04,0x0008,0x10,0x0240,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4049,4051,4051,4050,16151,16620,0,0,0,0,0,0,0,0,0,721,14.4,16.1,197.1,197.1,195.7,16.1,-273.2,17196,0,0,0,0,2264,SUCCESS

  • 0 in reply to Darren DeBattista1
    TI__Mastermind 37981 points

    Hello Darren,

    It is most important to look at the Operation Status A register and look at Bit 1 and 2 ([DSG] & [CHG]), these bits tells you the status of the FETs. I see the issue is where charging is not happening when the CHG fet is on and the DSG fet is off. Can you send me the schematic of the board? 

    Regards,

    Adrian

  • 0 in reply to Adrian
    Intellectual 525 points

    Hi Adrian, 

    Please find attached the BMS schematic as requested. 

    3386.Schematic Prints.pdf

  • 0 in reply to Darren DeBattista1
    TI__Mastermind 37981 points

    Hello Darren,

    As I look over the schematic, can you run a test for me. Instead of toggling the FETs off, I want you to change the CUV protection to a high voltage, maybe around 3.5V. Discharge the battery to be below 3.5V and ensure that the CUV protection trips, this will cause the DSG FET to turn off but keep the CHG FET on. Now, see if you can pass a charge current through the battery. To run this test, FET_EN must be set to 1.

    Regards,

    Adrian

  • 0 in reply to Adrian
    Intellectual 525 points

    Hi Adrian, 

    I just made the test as requested:
    - set CUV to 3600mV
    - set CUV recovery at 3900mV
    - set FETEN = 1 (automatic fet control)

    discharged to cutoff with these result:
    DSG=0, XDSG=1, SS=1, CHG=1

    I applied a charge and the battery can charge normally.
    Infact to be honest we never had this problem in the field: when the battery reach a discharge cut-off point it can always charge.

  • 0 in reply to Darren DeBattista1
    TI__Mastermind 37981 points

    Hello Darren,

    Sounds good. I looked over the schematic and that looks good as well. Ideally, the toggle FET command should not be used when a current is actively flowing through the battery.

    Regards,

    Adrian