Power management

Hi, I have been trying to implement the L6983 in my design for about 4 month now and still don’t get the desired output. After checking the Fsw pin, it seems I don’t get any clock output, do you have any idea what would be the cause of this issue ? Here is m design.The 0Ohm strips are only for a backup power supply. The Fsw output is flat on GND at the oscilloscope.The SW output before the inductor is at my supply voltage of 28V with small disconnects resulting in a flat 28V after the inductor.The input is 28V and it should output 5.2VThe switching method should be 500kHz without ditheringVs is delivered by a L6981 power supply + L39200 LDO at 3V3. This issue is present on several iterations of this design even though we made sure to reference the ST eDesign Suite for our choices.

I have inherited a legacy H bridge motor control hardware and firmware based on L99H01 (I think L99H02 might be drop in replacement). I’m a firmware developer - not a hardware designer, and I’m new to motor control, so I’m familiarizing myself with the hardware and firmware, and I’m having a “how can this have ever worked” moment.The TS/ACT_OFF pin is not connected (floating). The value 0xC4 is written to REG3 by the firmware.EXT_TS-bit = high (thermal sensor interface), and EXTTH[5:0] is set to 000100b (n=7, m=3) , givingVth = 7* (0.31 + 3*0.03) = 2.8V.Vcc is 3.3V.Apparently this design has functioned correctly for over 10 years, but since we will shortly be spinning a new board and porting the firmware to a new (ST) MCU I’d like to understand if there is a fundamental problem with this design.  All of the original hardware and firmware developers are long departed (probably retired 😑).Thanks in advance if for any feedback.   

We are a large electronics company that has been collaborating with ST for over a dozen years.We are currently designing a wireless charger for one of our automotive clients and plan to launch mass production within a few months. Unfortunately, we are unable to test the hardware we have designed because we cannot obtain the necessary STSW-WBC2STUDIO software.Please provide access to STSW-WBC2STUDIO.Thank you in advance for your prompt assistance.Best Regards

Hello,We are designing an EVSE for a North American 120/240-V split-phase supply. The EVSE is connected to L1 and L2, with a nominal voltage of 240 V RMS between them. Neutral is not available at the EVSE.We would like to use the STPM34 to measure the L1-to-L2 voltage and calculate the load power and energy. Current sensing is implemented separately using current transformers and is not shown in the attached schematic.Our proposed voltage-sensing circuit uses the primary differential voltage channel as follows:L1 is connected to VIP1 through three series 560-kΩ resistors. L2 is connected to VIN1 through an identical resistor chain. Each input has a 1-kΩ resistor and filter capacitor connected to the local analog ground, iGND_A. iGND_A is the local ground of the isolated STPM34 metrology domain. It is not connected to neutral or protective earth.The intention is to create a symmetrical differential divider so that the voltage between VIP1 and VIN1 is proportional to the L1-to-L2 voltage

Dear supplier For P/N: STP5NK100Z certification we see just cocPlease mark the reason why you only provide a certificate of conformity (COfC) 1.2.3.4 which is correct ？ 1.     standard parts manufactured to a standard part specifition.2.     Part number is  part of a standard part manual3.    TSO authorization4.    None of the above reasonsTHANKSCHERRY  

Hello STM Team,I need LTSpice Model for SEA05TR for simulation verification. If possible, requesting to share. Regards,Yajush Sihag

Hello ST, I wonder if the top marking of STS10P4LLF6 is indeed 10P4L.Based on the latest datasheet (Rev 5, issued in Jan 2021), the top marking code is 10P4L.However, we received STS10P4LLF6 with “10K4L” but the date code is 2447. Could you please explain how this could happen?Best regards,

Hello everyone,I’m trying to communicate with a POWERSTEP motor driver via SPI using an STM32 (STM32F4) and the HAL library. I have a basic test where I send three bytes and read back the same number of bytes, but I always receive exactly the same data that I transmit (i.e., a loopback effect). The POWERSTEP does not seem to respond with its expected status bytes.SPI configuration (from CubeMX):hspi1.Instance = SPI1;hspi1.Init.Mode = SPI_MODE_MASTER;hspi1.Init.Direction = SPI_DIRECTION_2LINES;hspi1.Init.DataSize = SPI_DATASIZE_8BIT;hspi1.Init.CLKPolarity = SPI_POLARITY_HIGH;    // CPOL = 1hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;         // CPHA = 1  => SPI mode 3hspi1.Init.NSS = SPI_NSS_SOFT;hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB; Code snippet (simplified):uint8_t tx[3];uint8_t rx[3];tx[0] = 0x3B;   // example commandtx[1] = 0x00;tx[2] = 0x00; // Reset chipHAL_GPIO_WritePin(rstPOWERSTEP_GPIO_Port, rstPOWERSTEP_Pin, GPIO_PIN_RESET

Hey,I am having a big issue with ESD discharges and the STUSB4500. Essentially, I auto negotiate to 20V, and on ESD discharge, the STUSB shuts off VBUS_EN_SINK, while the supply continues to supply 20V. My thought is that on ESD discharge, the chip for some reason thinks it has had a disconnect event, waits for the supply to recover to 5V, but the cable has not been disconnected so continues to supply VBUS with 20V, and the STUSB then is in a hard stuck state until actual unplug and re-plug. There is no error seen, as GPIO does not pull low and is configured to show error states.I cannot find a document that exposes all of the register values, but after every shut down, the chip register state reads the same failure state. The dump is as below. # Before dischargeSTUSB4500 @ 0x28, registers 0x00..0xff 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f00: 00 00 00 00 00 00 12 00 11 20 00 63 fb 01 41 0a10: 0a 13 00 40 00 02 0c 2c 00 00 00 21 01 80 00 0020: 10 c8 5f 00 00 9c 00 02

Hello!on our project that use the SPV1050, we need to charge a small LiPo battery that have a 20mA maximum charging current. Could someone help me find a good solutions for regulate the current from BATT Pin?thanks in advance,Andrea

We are planning to use the 30 W Wireless Power Receiver IC (P/N: STWLC89JRO) in our product and would appreciate your support in providing the following information at the earliest:Technical Datasheet Design Guide / Reference Design Documents

Hi Sir, May i ask you to get the latest version 6.6 CMRT FOR TIP147,Thanks. Best Regard,Victor Lai

Hi Team,good day,may we seek your expertise regarding these two PNs.L9369-TR and L9369S-TR.Does the "S" suffix indicate a newer, improved model?What specific design changes have been made?Is there any official documentation from the manufacturer for S?thank you very much.

Dear ST Technical Support Team,I am currently working on the protection implementation of a flyback SMPS. I found the SEA05 suitable for CC/CV regulation due to its low component count, small footprint, and simple implementation.I would like to clarify the behavior of the SEA05 during a short-circuit condition.Our converter specifications are:Input voltage: 110 VDC nominal Output voltage: 15 V Output current: 5 ADuring a hard short circuit, the output voltage may fall close to 0 V. If the SEA05 is powered from Vout, its VCC will also fall below the specified minimum operating voltage of 3.5 V.In this condition, can the SEA05 still sink the optocoupler LED current through its output and maintain CC control, or does the IC stop operating once VCC falls below 3.5 V?If the SEA05 cannot provide CC control under this condition, please suggest a recommended method for implementing short-circuit protection with the SEA05.Thank you for your support.Best regards,Yajush

Good morning! What can I use to replace the VNH02H component?

Good morning! I need to replace an SCR with the code FLC 10 200, but it is out of production. What component can I use to replace it?

STGAP2SCMTR ST: During use, an issue has been identified. When the primary-side signal is 0 V, the secondary-side signal turns on spontaneously for approximately 500 ns. What is the cause of this?Symptoms: With the primary-side signal at 0 V (in the off state), the secondary side switches off normally under the influence of a low dv/dt (approximately 30 V/ns); however, under the influence of a dv/dt of approximately 60 V/ns, the secondary side switches on spontaneously for approximately 500 ns. The chip is rated at 100 V/ns;*This post has been translated from Chinese to comply with the ST Community guidelines.

Have use of L6599D in many power supplies from 50W to 300W, is L6599AD a direct functional replacement for any applications is expected to work exactly the same? Thank you.

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.A P-channel MOSFET is currently used for switching the solenoid.Case 1:Is it possible for the MOSFET to fail?Case 2:If the MOSFET fails, will it become an open circuit or a short circuit?Case 3:If the MOSFET fails in short-circuit condition, how can the circuit be protected  

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.Hi,Good day,May we seek your expertise for the following inquiry:1. What is the SPI frame format for L9369 RT?2. Is it configurable via SPI?3. What is the default SPI frame configuration for L9369 RT?Thank you.

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.在实际的汽车电子电路中，我们遇到一个问题，用efuse （VNF1048）去驱动电机，电机端会存在反向电动势，VNF1048驱动的外部的单NMOS无法做到防反功能，我们在实际电路上增加了一个NMOS，可以达到防反的目的（在efuse关闭外面NMOS时），想请教这样做有什么风险，在贵司规格书中未提及此种应用方案。 电路如如下：Google translation:In practical automotive electronic circuits, we encountered a problem: when using an efuse (VNF1048) to drive a motor, a reverse electromotive force (EMF) exists at the motor terminals. The external single NMOS driven by the VNF1048 cannot provide reverse protection. We added another NMOS to the actual circuit to achieve reverse protection (when the external NMOS is turned off by the efuse). We would like to inquire about the risks of doing this, as this application scheme is not mentioned in your company's specifications. The circuit is as follows. Please not that the language of the forum is English - see the Terms & Conditions

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.For the VNF9Q20F, the datasheet states that the exposed thermal pad (TAB) is VCC.Can someone confirm that the large exposed pad on the bottom of the package is electrically connected to VBAT/VCC and not GND?If so, should the thermal pad and all thermal vias underneath it be connected to the VBAT copper plane?

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.Can anyone identify this diode and suggest an alternative please?ST EETC453 

This account only shares restored community content posted by members between May 22 and June 9, 2026, who did not register for the new community.[image removed to prevent misuse of the numbers]

Hi, I have follow the DS12900 Rev 7 Figure 21 (Schematic example for USB Type-C at 2.5W with TCPP01-M12) and still can draw more that 1.5A from USB PD source, the voltage seen on CC1 is close to 1.4V (which corresponds to 3A capability). Not sure what is wrong/missing in the circuit;