电源管理论坛 - 最近的话题

TPS6521905: TPS6521905所有电源轨是否可以同时上电下电，即所有slot值为0ms

LIANG XU6 — Wed, 30 Sep 2026 07:23:34 GMT

Part Number: TPS6521905

TPS6521905所有电源轨是否可以同时上电下电，即所有slot值为0ms

RE: TPS6521905: TPS6521905所有电源轨是否可以同时上电下电，即所有slot值为0ms

Eirwen — Tue, 06 Oct 2026 04:20:02 GMT

需要根据图片上的时间以及6.3.1 上电时序章节的内容设计时序。

RE: TPS53667: 麻烦帮忙分析一下，是原理图的问题还是PCB布局布线的问题，TI有没有见到类似的问题，有什么较快的临时测试与改进方案

Eirwen — Tue, 06 Oct 2026 04:12:58 GMT

请参考评估板用户手册的回路图BOM和LAYOUT进行检查：

https://www.ti.com.cn/lit/ug/sluubh9/sluubh9.pdf

以及PMP22510的参考文件：

PMP22510 参考设计 | 德州仪器 TI.com.cn

TPS53667: 麻烦帮忙分析一下，是原理图的问题还是PCB布局布线的问题，TI有没有见到类似的问题，有什么较快的临时测试与改进方案

? ? — Mon, 28 Sep 2026 02:46:09 GMT

Part Number: TPS53667

麻烦帮忙分析一下，是原理图的问题还是PCB布局布线的问题，TI有没有见到类似的问题，有什么较快的临时测试与改进方案，麻烦帮忙看一下，分析一下原理图有没有可能有问题

现在电源设计输出0.9V 80A，但是电流跑到25A就上不去了，我将相位减到1相仍然能跑到25A，但是也在25A就卡住了，2相3相结果都一样，麻烦帮忙分析一下，TI有没有见到类似的问题，有什么较快的临时测试与改进方案，比如是哪些信号没有连接好会导致出现这种问题。

BQ76952: 初始化完成后，DSG默认是导通状态，我希望上电后是关闭状态，应该如何做

Yu Chao — Thu, 24 Sep 2026 01:21:56 GMT

Part Number: BQ76952

TI团队，你好

以下是Bq器件的初始化函数，我想请问的是如何操作能让Bq上电后，默认DSG是关断的，等待主机指令才能打开

int sBq76952Init(void)
{
int8_t sbRet = 0;
uint8_t ubBqPeotAValue = BQ_PROT_A_VALUE;
uint16_t uwBqAlarmMaskvalue = BQ_ALARM_MASK_VALUE;
uint8_t ubBqOcd1ThresholdValue = BQ_OCD1_THRESHOLD_VALUE;
uint8_t ubFetDefValue = BQ_FET_OPTIONS_VALUE;

pBqIicHd = sDrvIicInit(IIC2_INDEX);
if(pBqIicHd == NULL)
{
return BQ76952_ERR;
}
sbRet = sBQ76952CommPing();
if(sbRet != BQ76952_OK)
{
return BQ76952_ERR;
}
//进入参数配置模式
sBq76952EnterConfigUpdate();

//FET状态，上电默认关断 0x2D
sBq76952SetRegBlocking(BQ_DM_FET_OPTIONS,&ubFetDefValue, sizeof(ubFetDefValue));

//使能放电过流1级保护
sBq76952SetRegBlocking(BQ_DM_EN_PROT_A,&ubBqPeotAValue, sizeof(ubBqPeotAValue));

//Enables the FullScan and ADScan bits, default value = 0xF800
sBq76952SetRegBlocking(BQ_DM_DEFAULT_ALARM_MASK, (uint8_t*)&uwBqAlarmMaskvalue,sizeof(uwBqAlarmMaskvalue));

//OCD1阈值
sBq76952SetRegBlocking(BQ_DM_OCD1_THRESHOLD,&ubBqOcd1ThresholdValue, sizeof(ubBqOcd1ThresholdValue));

//退出参数配置模式
sBq769x2ExitConfigUpdate();
delayUS(10000);
//en fet
sBq76952FetEnableFirmwareControl();
// sBq769x2SendSubcommand(BQ_CMD_FET_ENABLE);
delayUS(1000);
// sBq769x2SendSubcommand(BQ_CMD_SLEEP_DISABLE); //测试打开
return BQ76952_OK;
}

int sBq76952FetEnableFirmwareControl(void)
{
uint16_t uwData;
BqMfgStatusT uwBqMfgSta;
int8_t sbRet = BQ76952_OK;
sbRet = sBq76952ReadMfgStatus(&uwBqMfgSta.value);
if (sbRet != BQ76952_OK) {
return sbRet;
}
if (uwBqMfgSta.bits.fetEn == 1) {
return BQ76952_OK;
}
/* FET_ENABLE FET_EN 0->1 */
return sBq769x2SendSubcommand(BQ_CMD_FET_ENABLE);
}

RE: BQ76952: 初始化完成后，DSG默认是导通状态，我希望上电后是关闭状态，应该如何做

Vivian Gao — Fri, 02 Oct 2026 11:57:18 GMT

不会

RE: LM2675-5.0EVAL: 输出电压纹波大

Eirwen — Fri, 02 Oct 2026 08:50:48 GMT

使用的是评估板吗？

LM2675-5.0EVAL: 输出电压纹波大

J Z — Wed, 23 Sep 2026 14:48:10 GMT

Part Number: LM2675-5.0EVAL

5v电压输出纹波较大是怎么回事？

TPS23881: Sifos PSA3000 test item info

willy shi — Thu, 01 Oct 2026 05:16:09 GMT

Part Number: TPS23881

Hi TI Team,

We are currently using the Sifos PSA3000 to evaluate the TPS23881EVM for IEEE 802.3bt Type 3 4-Pair operation.

During the test, we observed that the following two items are reported as Info:

Backoff_Voltage_Ss
Backoff_Time_SS

Are these two info results related to the TPS23881 IC design?

If so, should we ignore them without any compliance or interoperability concerns?

TPS23881EVM_PSA_Report.xlsx

RE: TPS23881: Sifos PSA3000 test item info

Daniel — Thu, 01 Oct 2026 10:46:18 GMT

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

RE: UCC28780: UCC28780 Debugging Issues

ROHAN SHAH — Thu, 01 Oct 2026 07:07:26 GMT

你好

很抱歉回复晚了，因为发布时我没有看到端到端视图。

这种现象是否引发了任何问题？

能否检查一下 UCC27712 器件的输出，以及 FET 的 PWML 和 Vgs，以便了解这种现象是由什么原因造成的？

问候

罗汉

UCC28780: UCC28780 Debugging Issues

Gabriel Wang1 — Fri, 11 Sep 2026 06:55:52 GMT

Part Number: UCC28780

Dear Expert

The attached files show the VSW and PWML waveforms measured under a 115Vac input condition. An abnormal waveform is observed: after VSW drops to 0V, it rises again. This phenomenon is particularly evident under the 10A output condition; no such issue has been observed in the 5A to 9A range; similar waveforms are also present below 5A, but VSW does not drop to 0V in these cases.
Similar abnormal waveforms also appear when the input is 270Vac high voltage
Transformer parameters: turns ratio 23:1:3, excitation inductance Lm=200uH, leakage inductance Lr=9uH, switching frequency 100kHz, with sandwich winding method.
I'd like to ask, from which directions can this abnormal waveform be investigated and improved?
I have attempted to modify the parameters of the RDM, RTZ, and BUR pins as well as the transformer's parameters and winding method, but there has been no improvement.

Schmetic

SCH (2).pdf

TPS544B28: Loop Response Adjustment Issue for TPS544B28

Chance Zhan — Wed, 30 Sep 2026 06:57:59 GMT

Part Number: TPS544B28

We are encountering a loop stability issue with the TPS544B28 during on-site debugging. At a switching frequency of 800kHz, the device experiences a power dropout approximately one minute after power-on. GUI displays the following alarms. Additionally, the measured SW waveform shows severe jitter.

Interestingly, the dropout issue does not recur when the frequency is increased to 1000kHz, though the severe SW jitter persists. The current GUI settings are shown below. Could you please provide guidance on how to optimize the loop response to resolve these issues? And the schematci is shown at the picture.

RE: TPS544B28: Loop Response Adjustment Issue for TPS544B28

Eirwen — Thu, 01 Oct 2026 04:03:13 GMT

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

RE: TPS6521905: TPS6521905所有电源轨是否可以同时上电下电，即所有slot值为0ms

Eirwen — Thu, 01 Oct 2026 04:03:10 GMT

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

RE: TPS23754EVM-420: POE fails to provide stable power delivery to POE+ (at) compliant devices.

Saah Sicarr — Wed, 30 Sep 2026 17:07:20 GMT

你好，

我想先看一下检测引脚的连接情况。您是否已经探测过该引脚的电流或电压，以了解握手过程的情况？

能否提供原理图文件或链接？我无法看到 VDD 和 VSS 线上的具体数值。

你的电容值是多少？你使用的是哪种TVS二极管？

此致，

萨阿

TPS23754EVM-420: POE fails to provide stable power delivery to POE+ (at) compliant devices.

vioralis vioralis — Fri, 04 Sep 2026 09:52:22 GMT

Part Number: TPS23754EVM-420

I am using the recommended circuit design of the TPS23754EVM-420, but I have selected PoE-only power supply without an adapter. However, during testing, the voltage cannot stabilize at around 50V; it basically fluctuates between 0-5V, meaning it has not entered the PoE detection phase at all. Yet, when I used a PoE port with an external 24.9kΩ resistor, the oscilloscope showed an irregular rise to 52V and then a drop, which indicates the PSE is working normally. But once connected to my PCBA, it cycles between 0-5V. Please help me identify the problem. The schematic is attached. Thank you very much, and I look forward to communicating with you.

RE: BQ76952: 初始化完成后，DSG默认是导通状态，我希望上电后是关闭状态，应该如何做

Yu Chao — Wed, 30 Sep 2026 06:18:49 GMT

嗯嗯，我试了下，配置成低有效，上电时是拉低的，但主机发送开启指令不生效，我看DFETOFF引脚原理图中是直接接地的，如果使能的话会一直拉低，主机发送开启指令还会生效吗？

RE: BQ78706: 无法获取BQ78706完整数据手册

Alice — Wed, 30 Sep 2026 03:53:49 GMT

您好，

请使用公司邮箱注册的TI账号，在产品网页申请。

BQ78706: 无法获取BQ78706完整数据手册

Zhang Hanzhao — Wed, 30 Sep 2026 03:05:21 GMT

Part Number: BQ78706

无法获取BQ78706完整数据手册

PMP23547: 请帮忙看下这个demo是否能购买，或者借给客户测试呢，多谢

user4645094 — Wed, 30 Sep 2026 03:10:48 GMT

Part Number: PMP23547

请帮忙看下这个demo是否能购买，或者借给客户测试呢，多谢

RE: PMP23547: 请帮忙看下这个demo是否能购买，或者借给客户测试呢，多谢

Alice — Wed, 30 Sep 2026 03:50:18 GMT

您好，

很遗憾，参考设计PMP23547并没有硬件供客户测试。

链接帖子提供了此参考设计的设计资源，请参考。

PMP23547: design data, theory of operation - Simulation, hardware & system design tools forum - Simulation, hardware & system design tools - TI E2E support forums

PMP23547: BOM of GaN-Based 8kW 3-Phase Totem-Pole PFC and 3-Phase LLC Reference Design - Simulation, hardware & system design tools forum - Simulation, hardware & system design tools - TI E2E support forums

TPS6521905: EN引脚实现有效控制时间要求

LIANG XU6 — Wed, 30 Sep 2026 03:16:45 GMT

Part Number: TPS6521905

Teeprom_load=2.3ms，如果使用EN引脚控制PMIC启动，至少需要在VIN输入电压5v就绪后2.3ms才能实现有效控制吗

RE: TPS6521905: EN引脚实现有效控制时间要求

Vivian Gao — Wed, 30 Sep 2026 03:32:28 GMT

感谢您关注TI产品。我们正在核实您的问题，请耐心等待我们的回复。

TPS6521905: TPS6521905 buck和LDO是否可以输入不同电压

LIANG XU6 — Wed, 30 Sep 2026 03:18:31 GMT

Part Number: TPS6521905

LDO的输入电源必须连到VSYS吗，我打算buck部分连到5v，lDO1输入5v，输出3.3v，LDO234输入连到2.3V，输出1.8v 1.0v降低损耗可以吗？