Power management

Hello,I'm encountering an issue with the ST1S12G18R DC/DC regulator. I've attached the reference schematic from the datasheet and my PCB layout, created in Altium. As you can see, my design matches exactly with the reference schematic provided by ST.According to the datasheet, with approximately 5V input and the recommended reference schematic resistor values, I should obtain 1.2V at the output (56k ohm resistor used for both feedback resistors). However, I'm consistently measuring around 4V instead of the expected 1.2V.Because I specifically need a 3.3V output in my design, I adjusted the feedback resistors to 150 k ohm and 33.2 ohm. Still, the output voltage remains stable at approximately 4.3V when the input voltage is in the range of 4.5V to 6V. Only when the input voltage drops below 4V does the output voltage start decreasing accordingly. This behaviour indicates to me that the feedback loop may not be actively controlling the output voltage as intended.To further investigate, I

I need to calculate and estimate the required thermal resistance and temperature in operation for thermal design. When I read in Section 3.1 of datasheet, I do not see the Rja I can use directly, instead, it presents a chipset configuration with various Rja parameters. What does the chipset configuration stands for, is this configuration for 3 VNH5019A-E chips or 3 partitions in one VNH5019A-E? and how to understand Table 17 (thermal calculation in clockwise and anti-clockwise operation)? Thanks!

From what I can read on this diode it is from ST for sure, and it says VU beside the logo, the next line is M R, and the last line is GP922.   Any help would be appreciated.

Hi,When we were using the STWBC86JR as the wireless charging TX, we encountered a problem. The design is defined as wirelessly charging the battery and supporting the product's operation. The tested charging efficiency was relatively low, only 43%. When the device was turned off, only supplied power to the battery, and the efficiency was only 32%(the battery was set to current limit). This means that a large part of the energy is converted into heat energy. We have adopted a cooling solution, but still hope to improve the charging efficiency. Can I ask if you have any suggestions? The currently used TX coil is 6.2uH, with a diameter of 20mm. The working frequency measured at stability is 102kHz. We found that reducing the spacing between the TX and RX coils can increase the efficiency by 50%. However, since the shell (about 2mm) cannot be thinner, reducing the spacing is not feasible. Currently, there is no other solution. Could you help us find some ideas to improve efficiency?Thanks！

Hello experts, I have a question about how to determine the resistance value.In STEVAL-WLC38RX circuit schematic, R4 = 200, R5 = 200, R6 = NA.What is the idea behind the values you set?The electrical characteristics in the datasheet for STWLC38 state Imax = 0.3[A](*1) when Vrect = 5 to 10[V].   (*1)Non-repetitive 100 ms rectangular pulseAre the resistance values based on these ratings?Or is it set based on an experiment?For now, I plan to use two of the same resistors as on the evaluation board.Note that only the BPP will be implemented. Regards, Ryoma

Hello Team, I am looking for an N channel MOSFET as Low side switch for Capacitive Load.Application is to generate sharp negative pulses as below.Supply Voltage range: 25V to 450VPulse width: 25nsec to 9usecPRF: 0.5msecPulse current is 8Amax for 9usec.MOSFET Gate is driven with a gate driver of 1A current source/ sink Thanks  

hello dearwe have this BULK ID, and i want to know wich is the DATA CODEcan you help meor i have to give you the trace code?

Hello! I'm developing a project with the L6480H integrated circuit, using the EVAL6480H board for SPI communication. However, I have a problem: the L6480H only echoes the commands I send via SPI. Regarding the hardware, I soldered the jumpers JP1, JP3, JP5, and JP8 according to the UM1685 manual. When I turn on the EVAL, the FLAG LED lights up, and the board only echoes it. Even after resetting the STDBY_RESET pin and getting the STATUS register, the board still has the FLAG active. Could you please tell me if there's anything I can do? Or if there's a procedure to initialize the board? I couldn't find it in the manual. Thank you for your attention!

Hello.I would like to know the maximum Tj value of L78.I think the junction temperature of silicon semiconductors is generally 150°C, but the data sheet states that the operating junction temperature range is 0 to 125°C for L78 and 0 to 150°C for L79.The solid line in Figure 31 of the data sheet seems to go up to 150°C,but is the starting point for thermal design 125°C?Thank you in advance.

Hello Team，I found both STTH20003TV1 and STTH20003TV are available on the market.Unfortunately, I cannot find STTH20003TV1 in ST datasheet.STTH20003 - 300 V, 200 A Ultrafast Diode - STMicroelectronicsCould you provide the difference between STTH20003TV1 and STTH20003TV?What's the meaning of suffix '1' in the part number?Many thanks!Robert

I am using a STPD01 in a design for USB PD. Neat little part but I'm finding during testing that setting 15V output on this part immediately causes it's internal switching FET that most be located near the PVIN/VCC pins of the package to self destruct and short. The result is package damage and enough current is drawn to vaporize the large copper pour next to it. For values below, say 13V, it has been fine. Is there anything non-obvious I missing in the schematic here? The chip should be fairly straight forward.The PPOWER_P input is 21V during testing and there is no load on the output.

I'm trying to identify this two terminal components. It has these identifiers on it "CBJ GP 950", but there is a chance the GP is a 6P, but G looks correct. There are not cathode markings so I'm guessing it's not a diode, unless it's bidiretctional.  Please help!    

HI Sir，we have two different results of the ripple noisebase on same PCBA design, but different L7987 origin:1. Mark of "ST e3 G9207，L7987， CHN 3L0"，ripple noise 2.2V 2.9KHzinput 24V， output 12V， load 5ohm 2.4A 2. Mark of "ST e3 7B658， L7987， PHL 037"，ripple noise 0.04V input 24V， output 12V， load 5ohm 2.4Athe image of the chip and the image of the ripple see below.why is it like that, it make no sense，could you please advise.thanks.with best regards,PZhaL7987 CHN 12V 2.5A, 24V inL7987 PHL 12V 2.5A, 24V inL7987 CHNL7987 PHL     

Good morning; I want to do a simple relay controlled by my nucleo board; so I did a simple circuit with the STP55NF06L; however, it does not work as expeted, in real ife, even when I am not sending voltage to the gate, the transistor conducts electricity, however in the simulation, it works with a similar Transistor, i want to know if this transistor is correct or if I should use another one

Hi! I need a SPICE model for T2535T-8I. I couldn't find it anywhere. Please help! Thank You!

Hello,I want to use 3x mentioned devices in a usb hub to deliver pover to peripherals.Does anyone has experience with something like this? Can it negotiate with three different devices or it will cuse some trouble.? Best regards, Mrdjoni  

Hello,For the past few days, I’ve been trying to operate the VIPer35 quasi-resonant  offline high-voltage converter, but I haven't been able to get any output. I attempted to bypass or disconnect the output of the PC817 optocoupler and also tried shorting it—still, no pulses were generated. I also connected the ZCD pin directly to ground and then to VDD in another attempt, but there was still no output. Additionally, I tried powering the VDD directly with 15V and even applied 230V AC through a variac, but no pulses appeared.I need guidance on how to generate pulses or how to properly trigger the VIPer35 IC.In the oscilloscope yellow graph is Vds and Blue graph is Vdd

Hi,   We have build a led driver circuit using STP40NF20 -- 2 nos in parallel, the issue i am facing oscillation issue in Drain pin (Vled ), So kindly support in this regards..

I have ST1PS02D1QTR (output discharge disabled variant). However, I am observing that if AUX = low but external 1.2V is applied to VOUT2, I get power dissipation that seems in-line with output discharge resistance on VOUT2. My question is this: does ST1PS02D1QTR still have the VOUT2 Rdisc2 Auxiliary output discharge MOSFET on-resistance (discharger)?

A design I am debugging is utilizing Y5V dielectric capacitors on the input and output of the L4931. There is a 2.2uF capacitor directly at the output and another 2.2uF capacitor on the other side of an ~4 Ohm resistor that analog supplies are used off of.Are there any concerns over temperature for using this dielectric type with this LDO? I know that Y5V tends to have a pretty variable capacitance over the operating temperature range of this LDO. I wanted to check in and see if there is any margin on the LDO for the stability capacitor requirement that would accommodate this capacitor dielectric type.I also wanted to check in and see if there are any suggestions for performing a test for verifying if excessive transients are present due to a potential lapse in stability over temperature of the circuit. 

I have recently designed the STEF01FTR into a design that sits on the main input rail. The input is specified to run from 9V-48V. As a result the output VClamp is set the 52V max by setting R122 to 560K and R126 to 10K. When our initial FAI boards arrived the STEF01 was clamping the output voltage to a maximum of 32V. I have attempted to increase the VClamp voltage by increasing R122 but that didn't seem to have any effect. I attempted to double both R122 and R126 and that also didn't have any effect. I decreased R122 to 200k and was able to drop the VClamp voltage but I can't seem to get it above 32V which seems to contradict the datasheet. Has anyone else experienced this behavior or have any ideas as to what could be causing this? This behavior is consistent across numerous boards and we are operating under very light loads currently.  

Hi I am using STCS1APUR to drive 10LEDS IR, (MTSM5116MT2-BK), circuit belowcurrent should be 1A as of f/b resistance, enable gets turn on as sson as the STM32 MCU comes up, supplying a 3.3VDC PWM though the MCUissue:the voltage drop across the led is only 0.6VDC, and they are dim, when checked the current , its less than 0.04A across the LEDSwhen there is no trigger there is a 4VDC deop cmpared to the +VLED(24VDC)i read the sheep twice and unable to figure out the issueon time is 250msec

Hi,I would like to use the VIPER319HDTR and would like to check the thermal to see if Tj will be an acceptable value.However, the switching losses of the internal FET are not mentioned. Is the switching time of the internal FET known? Or is there another way I can verify the thermals of the device?Thank you in advance!Kind regards,Beau Wilmink

Dear STMicroelectronics Support Team, I have built a custom wireless charger based on the STEVAL-WBC2TX50 evaluation board, following the provided BOM and schematics. I successfully flashed the STSW-WBC2FW_V1300 firmware into the STWBC2-HP controller chip and connected to the STSW-WBC2STUDIO GUI to monitor system behavior. I understand that Qi 1.3 devices will not charge due to authentication requirements. However, I would like to confirm whether I should be able to charge Qi 1.2 and older devices (e.g., iPhone 11) since they do not require authentication. If I should be able the charge Qi1.2 devices, this suggests an underlying hardware issue in my design. Currently, the GUI event window continuously shows "ping_timeout" errors, as seen in the attached screenshot. Could you please provide guidance on potential causes and troubleshooting steps to resolve this issue? Thank you for your support.

Hello STMicroelectronics Community,I'm working on a project using the STEVAL-WBC2TX50 evaluation board and would greatly appreciate any information or insights you can share. I currently have the PDF schematics from https://components101.com/sites/default/files/2024-05/steval-wbc2tx50-datasheet.pdf, but I lack design files, BOM, or additional details, and there seems to be no further information available on STM or online. Any reference designs, schematics, BOM, or troubleshooting tips would be incredibly helpful.Thank you for your support!@willzhou