Project Overview and Analysis
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Project
Schematic
Using Schematic Tool.
Planning to use tools.
Identifying existing components.
Responding in Chinese.
Linking components cautiously.
Preparing to ask about adding components.
下面是对当前工程中“功率级定位”的核查结果（按你提出的四项：三相桥、门极驱动、母线电容、分流电阻）。本项目为单页原理图，未拆分多页。
功率级元素定位结果
- 三相桥功率级（6×MOSFET/三相桥模块）
- 结果：未找到匹配器件
- 位置/页：当前工程仅一页，未放置
- 门极驱动器（半桥/三相门极驱动）
- 结果：未找到匹配器件
- 位置/页：当前工程仅一页，未放置
- 直流母线电容（DC-Link，大容量低ESR电容并MLCC去耦）
- 结果：未找到典型“母线电容”用途与封装（现有电容均为小容量去耦/补偿）
- 位置/页：当前工程仅一页，未放置
- 分流电阻（母线/相电流取样用低阻分流器）
- 结果：未找到低阻、开尔文引脚类分流电阻
- 位置/页：当前工程仅一页，未放置
与功率级无关但可能混淆的已存在器件（用于本工程的模拟前端与数字系统）
- 高速运放（模拟前端，±6 V 供电）
- 小容量电容（去耦/补偿，非DC-Link）
- 电阻网络（偏置/反馈，非分流取样）
- 数字与外设（与电机控制无关）
结论
- 当前工程（环境辐射记录器示例）未包含你要查找的电机功率级相关器件：三相桥、门极驱动、母线电容与分流电阻均未放置。
需要我在此工程中新建并放置“PMSM三相桥功率级+门极驱动+DC-Link去耦+电流采样（两分流/三分流/母线分流）”模块吗？如果确认，我可以为你准备执行计划并按你的采样方案与功率等级（300 W）放置相应器件与接口。
确认工程不对
按“电机功率”网络找
按封装/器件类型找
定位±6V电源用途
13 days
Ready to start.
Show Plan
Is the microcontroller wired correctly?
@copilot Is the microcontroller wired correctly?
2y
Yes, the microcontroller (U3, STM32F030C6T6) appears to be wired correctly. Here are some of the connections:
- VDD pins are connected to the +3.3V power supply (Net 0).
- VSS and VSSA pins are connected to the ground (Net 4).
- I2C1_SCL (PB10) and I2C1_SDA (PB11) are connected to Net 9 and Net 10, respectively, for I2C communication.
- UART1_RX (PA10) and UART1_TX (PA9) are connected to Net 2 and Net 17, respectively, for UART communication.
- SPI1 signals, SCK (PA5), COPI (PA7), CIPO (PA6), and CS (PA4), are connected to their respective nets (Net 26, Net 1, Net 19, and Net 7).
Other control and monitoring pins like PA1, PA2, PA3, PA8, PA11, PA12, and PA13 are also connected appropriately. Overall, the microcontroller appears to be wired correctly based on the provided schematic.
2y
I'm worried about BOOT0, what does that do on the MCU?
2y
BOOT0 is a pin on the STM32F030C6T6 microcontroller used to select the boot mode during the startup process. By setting the BOOT0 pin state (either high or low), you can choose whether the MCU boots from its internal Flash memory, or an alternate boot source like system memory or bootloader for programming/firmware update purposes.
In the provided schematic, BOOT0 is connected to U3:PB8. For normal operation, you would generally connect BOOT0 to ground (low) so that the MCU boots from the internal Flash memory. However, if you ever need to update the firmware or use an alternate memory source, you can control the BOOT0 pin using the GPIO PB8 on the MCU. Keep in mind that this might require additional software configuration to ensure proper functionality.
2y
thanks! I'll tie it low then
2y
You're welcome! Tying BOOT0 low is a good choice for normal operation, as it ensures that the STM32F030C6T6 microcontroller boots from its internal Flash memory. If you need to update firmware or use an alternate memory source in the future, you can always modify the connections and software configuration to account for those changes. If you have any more questions or need further assistance, feel free to ask. Good luck with your project!
2y
4
I just built this circuit and I'm seeing -4V on the output of the op amp cascade...
@copilot I just built this circuit and I'm seeing -4V on the output of the op amp cascade. Any ideas what could've gone wrong?
2y
There could be several reasons for the -4V output on the op-amp cascade. Some possible causes include:
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Incorrect component values: Double-check the resistor and capacitor values in the circuit to ensure they match the schematic.
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Soldering issues: Inspect the solder joints for any shorts or cold solder joints that could affect the circuit performance.
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Damaged components: It's possible that one or more components, such as the op-amps, could be damaged. Verify that the components are functioning correctly.
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Power supply issues: Ensure that the power supply is providing the correct voltage levels to the circuit.
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Oscillation or instability: The op-amp cascade might be oscillating or unstable, causing unexpected output voltages. Check for proper compensation and stability.
I recommend going through these steps to identify and resolve the issue.
2y
i checked all of these and none are the problem. I'm seeing a 500kHz ripple on the output overlayed over the -4V output.
2y
If you're seeing a 500kHz ripple on the output, it could be due to oscillation or noise coupling into the circuit. Here are some suggestions to address this issue:
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Bypass capacitors: Ensure that proper bypass capacitors are placed close to the op-amp power supply pins to filter out high-frequency noise.
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Grounding and layout: Verify that the PCB layout has a proper ground plane and that the signal traces are routed away from noisy components or traces.
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Compensation: Check the op-amp compensation and feedback network to ensure stability. You may need to adjust the component values or add additional components to stabilize the circuit.
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Shielding: If the circuit is sensitive to external noise, consider adding shielding around the op-amp cascade to minimize interference.
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Input filtering: If the noise is coming from the input signal, consider adding a low-pass filter to the input to reduce high-frequency noise.
Investigate these areas to identify and resolve the ripple issue.
2y
what else could be causing the -4V on the output?
2y
One possible cause of the -4V output could be output voltage phase-reversal, which occurs in some op-amps when the input common-mode voltage is exceeded. This issue is typically caused when one of the internal stages of the op-amp no longer has sufficient bias voltage across it and subsequently turns off, causing the output voltage to swing to the opposite rail until the input comes back within the common-mode range. This issue is most often associated with JFET and/or BiFET amplifiers, but some bipolar single-supply amplifiers are also susceptible to it. To address this issue, you may need to ensure that the input common-mode voltage is within the specified limits for the op-amp you are using. Source
2y
5
How can I configure this op amp to get 100dB of gain with 20kHz of bandwidth whi...
@copilot How can I configure this op amp to get 100dB of gain with 20kHz of bandwidth while biasing the input at 4V?
2y
To configure the OPA847 (U5) for a gain of 100 dB (~3162 V/V) at a bandwidth of 20 kHz, you can use a two-stage approach with the input biased at 4V. Here's how you can do it:
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First, determine two gains to reach a total gain of 100 dB. For example, you can choose two gains of 50 dB each (316.2 V/V).
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For both stages, you can use a non-inverting amplifier configuration. To set the gain of each stage to 50 dB, you'll need to select appropriate resistor values for the feedback resistors Rf and Rin.
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The gain in a non-inverting amplifier configuration is determined by the resistors' ratio: Gain = 1 + (Rf/Rin). To get a gain of 316.2 V/V, you can choose Rf at 316.2 kΩ and Rin at 1 kΩ.
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To bias the input at 4V, you can create a voltage divider using two equal-value resistors (e.g., 10 kΩ) between the V+ rail (assumed to be 8V) and GND. The midpoint of the voltage divider can be AC-coupled to the non-inverting input of the first-stage op-amp using a series capacitor (e.g., using a 1 µF capacitor).
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The 20 kHz bandwidth can be set by a low-pass filter at the output of the second stage using an RC-filtro (Rf and Cf). The cutoff frequency is given by fc = 1 / (2π * Rf * Cf). For a 20 kHz bandwidth and using Rf = 316.2 kΩ, Cf ≈ 25 pF. You can select the nearest capacitor value available.
Note that this design assumes the OPA847 has sufficient bandwidth and can provide the required output voltage swing for your application. Be sure to check the datasheet for the specific device to ensure its performance characteristics meet your requirements.
2y
would the OPA847 have enough bandwidth to achieve 50dB of gain at 20kHz?
2y
The OPA847 has a gain-bandwidth product (GBP) of 3.9 GHz. To determine if the op-amp has sufficient bandwidth to provide 50 dB of gain at 20 kHz, you can calculate the required bandwidth for the desired gain and compare it to the GBP.
First, let's convert the gain from dB to a linear value:
Gain (linear) = 10^(Gain (dB) / 20) = 10^(50 / 20) = 316.2 V/V
Now, we can calculate the required bandwidth for the gain:
Required bandwidth = Gain * Signal bandwidth = 316.2 * 20,000 Hz = 6.324 MHz
The required bandwidth (6.324 MHz) is much lower than the OPA847's GBP (3.9 GHz), so the OPA847 should have sufficient bandwidth to achieve 50 dB of gain at 20 kHz. However, you should also ensure that the output voltage swing and other device characteristics meet your requirements by referring to the device's datasheet.
2y
thanks copilot!
2y
You're welcome, Mark! If you have any more questions or need further assistance, please don't hesitate to ask. I'm here to help!
2y
@copilot, I just noticed my rail is 6V. How would I make a voltage divider to get 4V out?
2y
To create a voltage divider that outputs 4V with a 6V input, you'll need to choose two resistors with the right ratio. The output voltage (Vout) for a voltage divider is determined by the following equation:
Vout = Vin * (R2 / (R1 + R2)),
where Vin is the input voltage (6V), R1 is the resistor connected to Vin, and R2 is the resistor connected to ground (GND). To find the ratio R2/(R1+R2) that will result in a 4V output:
R2 / (R1 + R2) = 4V / 6V = 2/3 ≈ 0.6667.
You can choose numerous resistor combinations to achieve this ratio, but some standard resistors to consider are R1 = 20 kΩ and R2 = 40 kΩ:
R2 / (R1 + R2) = 40 kΩ / (20 kΩ + 40 kΩ) = 40/60 ≈ 0.6667.
For this configuration, the output voltage will be:
Vout ≈ 6V * (40 kΩ / (20 kΩ + 40 kΩ)) ≈ 4V.
It's important to consider the input impedance of your op-amp stage so that the voltage divider output is not significantly affected. High impedance levels, typically in the MΩ range, are desirable. If necessary, use even larger resistor values for the voltage divider to achieve high input impedance while maintaining the desired ratio.
2y
How much noise is at the output if I configure the op amp for 50dB of gain
2y
To estimate the noise at the output of the op-amp configured for 50 dB of gain, you need to consider the various noise sources associated with the op-amp and the input network, such as input voltage noise, input current noise, and resistor thermal noise.
The OPA847 datasheet provides the following typical values for input voltage and current noise:
- Input voltage noise density: 1.1 nV/√Hz
- Input current noise density: 2.2 pA/√Hz
Assuming your input network consists of resistors RIN and RF, their thermal noise can also contribute to the overall noise. The thermal noise of a resistor can be calculated using:
Noise density = √(4 * k * T * R),
where k is Boltzmann's constant (1.38e-23 J/K), T is the temperature in Kelvin (assume room temperature, 298 K), and R is the resistance.
For RIN = 1 kΩ:
- Thermal noise density ≈ √(4 × 1.38e-23 × 298 × 1e3) ≈ 4.07 nV/√Hz
For RF = 316.2 kΩ:
- Thermal noise density ≈ √(4 × 1.38e-23 × 298 × 316.2e3) ≈ 22.6 nV/√Hz
The total input noise density can be estimated by adding the noise sources (op-amp and resistors) in quadrature:
Total input noise density ≈ √(1.1^2 + 4.07^2 + 22.6^2) ≈ 23.0 nV/√Hz
To get the total output noise, multiply the total input noise density by the gain:
Output noise density ≈ Gain * Total input noise density ≈ 316.2 * 23.0 nV/√Hz ≈ 7.26 µV/√Hz
To calculate the output noise over a specific bandwidth (e.g., 0 to 20 kHz), integrate the noise density over the frequency range:
Output noise (0 to 20 kHz) ≈ Output noise density * √(Bandwidth) ≈ 7.26 µV/√Hz * √(20e3) ≈ 324 µV
Keep in mind that these values are rough estimates based on typical noise densities provided in the datasheet. Actual values may vary depending on the specific device and operating conditions.
2y
8
Reviews
- Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portaljharwinbarrozo43.0M
- Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #powerjharwinbarrozo11.4M
- A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibraryjharwinbarrozo1.5M
- A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibraryjharwinbarrozo1.5M
- A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #genericsjharwinbarrozo15.5k
- An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.Terminal
- 47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlinkjharwinbarrozo1.2M
- 10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcanjharwinbarrozo1.2M
- Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlinkjharwinbarrozo1.1M
Project Outline:
Microcontroller
RTC
Dosimeter Op Amp Stage
See DigiKey BoM for the Analog FrontEnd: www.digikey.com/en/mylists/list/476AJE8R2I
Properties
Properties describe core aspects of the project.
Pricing & Availability
Distributor | Qty 1 |
|---|---|
Digi-Key | $14.23–$14.81 |
LCSC | $16.38–$17.69 |
Mouser | $14.59 |
Assets
IncessantBlabber-Radioactive-symbol.svg
IncessantBlabber-Radioactive-symbolDefaultControls
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markwuflux
copilot
INT/SQW pin (pin 3) of IC1 to an available GPIO pin on the microcontroller, if you plan to use the interrupt/square wave output feature.