https://e2e.ti.com/support/power-management-group/power-management/<p style="display:none;">blank</p>en-USTelligent Community 13https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686568/bq25750-power-path-switchover-from-battery-to-acThu, 01 Oct 2026 14:09:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:c7620b63-92b7-467a-8d3f-9b46704ae7fbKarlis TucsPart Number: BQ25750 I am having weird issue where Vsys voltage collapses if PSU is turned of to supply energy from AC. Low the output voltage of PSU bigger the chances of Vsys voltage dip. But strange thing is - PSU voltage in all cases is connected to Q1 only when it is stable 50V in this case. So it seems like voltage of turned off PSU should not affect anything, but it does. Or maybe it is just time passed from Vac turn off event. I dont know. Please advise. I have tried to get to solution of this for 2 days with help of AI.BQ25750https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686545/tps62002-intermittent-boot-failure-related-to-tps62002-startup-behavior/6499601Thu, 01 Oct 2026 13:55:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:89192777-c037-4dae-b72f-1c4842e912d1Josef MarsmannHi Jeremias, Thanks for using E2E. Could you please explain all 4 curves in the plot and provide the same plot for the good unit in addition. The Vin curve shows a max of 6.5V! Our device is designed for Vin max=5.5V and absolute maximum rating of 6V at Vin. Why it&#39;s so high? Have you done a ABA test already means populate a failing board with a good unit and back the fail unit to exclude any board or BOM tolerance issues. Please do an additional test: Power the device with 5V with EN = low Set EN to high Does the device fails also? Is the device failing with ILIM=high also? Best regards, Sepphttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686298/bq25798-do-i-need-to-use-rbfet-and-acfet-for-my-backup-mode/6499590Thu, 01 Oct 2026 13:40:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:35aa87c9-e100-41d5-b24d-7fcc5d5063d7Robert WalkerHey Jeff, Ok, just to close this out, one final question for calcification. Is it fully supported to operate indefinitely with DIS_ACDRV=1 while using: PPHV to VBUS for charging PMID backup mode VAC1 monitoring and never allowing the charger to connect VBUS to VAC1? Thanks again! Roberthttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686559/bq27542evm-abnormal-ratableThu, 01 Oct 2026 13:35:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:cb267a3e-51ce-4541-8219-f32f40398225Iris TsaiPart Number: BQ27542EVM Hi Experts: Regarding Ra values question, could abnormal Ra values ​​lead to serious battery safety issues, such as battery leakage or swelling? Thank you.BQ27542EVMhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686537/tps653860-q1-full-technical-design-and-development-support/6499582Thu, 01 Oct 2026 13:34:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:53427578-62d4-4e08-97cc-4f2441e9c90dKatie PierHi Vinod, The TPS653860-Q1 full datasheet, TRMs, and Functional Safety documents are available only under NDA. If you have NDA with TI, access to requests for the secure folder will be approved: https://www.ti.com/drr/opn/TPS65386XX-Q1-DOCS However, looking up the company listed in your myTI account, I don&#39;t see an active NDA with TI. Regards, Katiehttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686298/bq25798-do-i-need-to-use-rbfet-and-acfet-for-my-backup-mode/6499581Thu, 01 Oct 2026 13:33:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:bdf3addb-45c1-45b9-8163-15e908468d15Jeff FHi Robert, Yes. If a voltage is sensed on VAC1, the charger auto turns on the MUX FETs unless the DIS_ACDRV bit =1. Regards, Jeffhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686298/bq25798-do-i-need-to-use-rbfet-and-acfet-for-my-backup-mode/6499579Thu, 01 Oct 2026 13:32:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:11a97535-2ac0-4e6a-bdfd-c16f9542f837Robert WalkerHello Jeff, I&#39;m asking a slightly different question. When charging from USB-C through VBUS with VAC1 already powered from VIN1, does BQ25798 ever automatically assert ACDRV1? Is there a specific charging or backup-mode scenario where the charger must turn on ACFET/RBFET even though I do not want USB-C to power the system rail VIN1? Thanks! Roberthttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1685693/tps542021-efficincy-in-inverting-buck-boost-config/6499578Thu, 01 Oct 2026 13:31:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:16d52bd1-1653-4cd3-9575-2fe993da5300Jagadeesh EgalaHi Jackson, Hope all is well, When we use TPS542021 in inverting buck boost configuration, the efficiency will be lesser than the standard buck configuration for the below reasons: In an inverting buck-boost configuration, the inductor current must supply the load only during the off-time of the switch. Hence, the inductor average current skyrockets to a high value which increases conduction losses inside the TPS542021 FETS and the external inductor’s DC resistance. In a standard buck, the average inductor current will be equal to output load current. In an inverting buck-boost configuration, Because the IC ground pin is tied to the negative output voltage (-V out ), the chip &quot;sees&quot; a total voltage span of V in +|V out | across its VIN and GND pins. As Switching losses are directly proportional to the square of the voltage transitioning across the switching node. Since V sw = V in +|V out | in IBB, capacitive charging/discharging losses and turn-on/turn-off transition losses dramatically increase. Also, the ripple current across the input and output capacitors will increase which in turn increases the conduction losses inside capacitors’ ESR. Considering all this, the inverting buck boost configuration will be 6% to 16% worse than the standard buck configuration while delivering the same amount of output power. Please refer the app notes below which has more details on using a standard buck IC in an inverting buck boost configuration. Using the TPS5430 As An Inverting Buck Boost Converter (Rev. A Working with Inverting Buck-Boost Converters (Rev. B) Using the TPS54x02 to Create an Inverting Power Supply Hope this information helps. Regards, Jagadeeshhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686300/bq25121a-bq25121a-pg-behavior-during-normal-charging-in-standalone-mode/6499575Thu, 01 Oct 2026 13:30:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:ac39e517-d64e-4efc-94cd-6d2fcee6bc6dSam BerendsenHi MJ, Yes, /PG will pulse in your application. The datasheet specifies that if VIN - VBAT falls within a certain window (0.825 V to 1.15 V), the device sends two 128 &#181;s pulses every minute to signal the input voltage status. Since your VIN - VBAT range is 0.8–1.2V, you will hit this condition. I recommend adding a software debounce or a longer timer on your MCU to filter out these pulses so they do not trigger a false docking event. Best, Samhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686418/bq76952evm-download-bqstudio/6499562Thu, 01 Oct 2026 13:17:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:2a09cf19-1051-4382-8ad3-786b1f623b38Mohammad FarhanHello Bob, Can you elaborate what problem you are having? BqStudio can be downloaded through this link BQSTUDIO Application software &amp; framework | TI.com . Regards, Farhanhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686357/bq25690-bq25690-not-charging-and-5v-on-vin-after-removal/6499548Thu, 01 Oct 2026 13:00:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:2777dd8e-2fc6-40e2-8b02-832f4f58f355Jeff FHi Ed, The charger will not work properly without a REGN cap. REGN powers the gate drivers for the internal FETs. Regards, Jeffhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686298/bq25798-do-i-need-to-use-rbfet-and-acfet-for-my-backup-mode/6499547Thu, 01 Oct 2026 12:58:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:4c131112-f3ee-4ea4-be26-5bd164951c72Jeff FHi Robert, The host can force the MUX FETs off with the DIS_ACDRV bit. I don&#39;t know how the TPS25751 responds to a voltage at PP5V when the VIN1 is applied and the input MUX FETs are turned back on. Regards, Jeffhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686044/tps6594-q1-tps6594-q1-i2c-connected-unable-to-reprogram-after-initial-program/6499541Thu, 01 Oct 2026 12:53:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:349757a7-4e40-4493-b255-889c9366f903Ethan BeyerNo worries Gabriel, hope everything goes well! Best Regards, Ethan Beyerhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686216/tps7b86-q1-thermal-implications-of-solder-voids/6499530Thu, 01 Oct 2026 12:47:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:aa6374ca-d57a-4532-a4fe-c0fe0f86a4a3Khai NguyenHi Aden, here are the requested parameters. Hope that helps Vin = 15V and Vout = 5V for LDO. Best Khaihttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686545/tps62002-intermittent-boot-failure-related-to-tps62002-startup-behaviorThu, 01 Oct 2026 12:41:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:fbf8c1b4-ad39-4005-8724-3936b3789f64Jeremias SchultzPart Number: TPS62002 We are investigating an intermittent boot issue affecting approximately 1% of production units. The TPS62002 is configured as a 5 V to 1.0 V converter supplying only the VDDCPU rail of a SAM9G25 processor. During failing startups, the 1.0 V output does not rise continuously. Instead, the output voltage exhibits a step-like ramp with intermediate plateaus before reaching regulation. When this occurs, the SAM9G25 fails to boot. On properly operating units, the VDDCPU rail rises smoothly and continuously to 1.0 V. We tested increasing the TPS62002 current limit by changing the ILIM configuration from GND to VIN, with no significant improvement. However, increasing the output capacitance consistently improves startup behavior. Adding a second 47 &#181;F capacitor significantly increases the boot success rate, and adding an additional 2.2 mF capacitor eliminates the failure during testing. Additionally, heating the output capacitor (47 &#181;F X7R, Taiyo Yuden LMK212BBJ476MG-T) increases the probability of a successful boot. Current design: TPS62002DGSRG4 Vin = 5 V Vout = 1.0 V L = 10 &#181;H (DO1608C-103ML, &#177;20%) Cout = 47 &#181;F X7R (LMK212BBJ476MG-T) Load: SAM9G25 VDDCPU only We would appreciate TI&#39;s support in understanding: Whether the observed step-like startup waveform could be related to compensation, stability, or startup behavior of the TPS62002. Any known concerns when using low-ESR MLCC output capacitors on the 1.0 V rail. Recommended output capacitance and ESR range for this application. Whether TI recommends a more robust drop-in or near drop-in replacement for TPS62002 in processor core supply applications. Oscilloscope captures of both successful and failed startups can be provided upon request. yellow: 1V TPS62002 Red: input 5VTPS62002Medical &amp; healthcarehttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1684809/bq24650-bq24650-won-t-recognize-a-healthy-lifepo4-battery-stuck-cycling-in-battery-absent/6499527Thu, 01 Oct 2026 12:40:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:ed946dbc-48a3-4d23-8352-aec6232cd192Michael HenriquezHi Christian, Thanks for following up. I&#39;ve attached the KiCad project (schematic + PCB) and PDFs of the schematic and the PCB copper layers, in case that&#39;s quicker to review. A note on how the files were prepared: since this is a public forum and the design is proprietary, I made a cleaned copy before posting. I removed the modules that have nothing to do with the charger (the MCU, Bluetooth and audio amplifier modules, plus the U1/U2 converters on the PCB). Because of that you&#39;ll see some unconnected wires on the MCU and Audio sheets, and a few empty areas on the board. Everything related to the charger path was left untouched: the BQ24650 (U6) and its full power stage, Rsense3, the VFB and MPPSET dividers, C4, the three LTC4359 selectors, the battery ADC divider (R4/R5) and the battery connector J_C1. That way you can follow the BATT_LFP_POS / SRN net completely. If you need anything that was removed, I&#39;m happy to share it privately. The files are the board as fabricated, with these differences: - Rework on the board not reflected in the files: 22pF added across Rtop2 (VFB divider), C4 reduced from 150&#181;F to 10&#181;F. - The LMQ61460 RT and EN/SYNC fix in the schematic was done after fabrication (unrelated to the charger). Measurements (all DC readings referenced to GND next to the IC): Input - VCC: 18.99V from a bench supply set to 19V, current limit 0.6A. The supply stays in CV mode the whole time, so it is not limiting. MPPSET - 2.545V while actively charging (~300mA), identical to the idle reading. Divider is 232kΩ/36kΩ, so the 1.2V threshold would only be reached with VIN around 8.9V. DPM doesn&#39;t look active. VFB - Divider Rtop2 = 590kΩ / Rbottom2 = 100kΩ (14.49V regulation target). - DC: 1.88V with the battery at 13.07V, consistent with the divider ratio. - Ripple: 240mVpp originally (before any rework). With 22pF across Rtop2 the scope reads 28-84mVpp. For reference, 22nF and 22pF across Rbottom2 made it much worse (680-960mVpp), so those were removed. Battery - 13.07V at rest, 13.16V while charging, so it should still be in the constant-current phase, far from the 14.49V CV point. Charge current - SRP-SRN: 12mV (I&#39;ve also seen it around 7mV), i.e. ~333mA with Rsense3 = 36mΩ. The bench supply shows 299-307mA, which agrees. - Design target is 40mV / 1.11A. - A 100nF across Rsense3 made no difference. TS - 2.02-2.06V with the real 10kΩ NTC attached to the battery. Same result as with the fixed test resistor, so a reduced-current temperature zone seems ruled out. Status - With the Rtop2 and C4 rework, the Charging/Suspended cycling stopped completely and it charges continuously, but the current settles at ~300mA instead of 1.11A. One thing I&#39;d like your opinion on: on this layout the SRN pin shares the BATT_LFP_POS net with the whole battery power path (battery connector, LTC4359 selector, VFB divider, battery ADC and C4) instead of having a dedicated Kelvin trace from the sense resistor. Could this explain the charge current settling well below the design target? Thanks again, Michael e2e.ti.com/.../Proyecto_2D00_Cargador.pdf e2e.ti.com/.../BQ24650_5F00_board_5F00_v1.ziphttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1681714/lm27762-lm27762-out--not-starting/6499517Thu, 01 Oct 2026 12:17:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:13d77370-bc82-4310-b297-ed376d983480Josef MarsmannHi Patrice, It looks much better now but I recommend to isolate the Cin, Ccpout and GND device pin net even more. Best regards, Sepphttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1684571/am62a7-sleep-wakeup-sequence-not-working/6499510Thu, 01 Oct 2026 12:07:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:ccaf014a-1ca3-487a-b748-49807cbcfd72H Vivek KrishnanHi Anshu, Can you create a private ticket to share the schematic? We have signed an NDA with TI. Thanks &amp; Regards, Vivekhttps://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686537/tps653860-q1-full-technical-design-and-development-supportThu, 01 Oct 2026 11:56:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:bcec207f-3945-4e5e-b0c4-61a46a7fb8a9VINOD SAINIPart Number: TPS653860-Q1 Other Parts Discussed in Thread: AM2612 , Hi TI team, We have selected AM2612 uC for our functional safety application and targetting for SIL-3/SIL-4. This TPS653860-Q1 IC is suggested by TI for safety applications for SITARA family microcontrollers. So we need full support for TPS653860-Q1 full technical details, its programming, hardware design, devlopment and troublshooting. Thanks and regards Vinod Saini Principal EngineerIndustrial AutomationAM2612TPS653860-Q1https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1686277/lm74930-q1-vs-cap-overvoltage-during-negative-surge/6499502Thu, 01 Oct 2026 11:52:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:782e24bf-7385-4970-8c89-78522206ee43&#214;nder ArikIEC 61000-4-5 Combination Wave (1.2/50 &#181;s – 8/20 &#181;s). https://www.powerelectronictips.com/surge-voltage-protection-considerations-faq/ The TVS in the entrance clamps the voltage around -55V.