修正PCB短路与浮铜
Worked for 4 mins 46 sec
已按“模块接口”完成输出级原理图骨架，没有放入任何错误的三脚 MOSFET 替代件。
已添加并连接：
CELL_DC_P / CELL_DC_N：输出单元直流母线接口CELL_OUT：半桥/多电平单元输出节点HS_GATE / HS_KS：高边未来 CI90N120SM4 的 Gate / Kelvin Source 接口LS_GATE / LS_KS：低边未来 CI90N120SM4 的 Gate / Kelvin Source 接口HS_GATE_DRV / LS_GATE_DRV：栅极驱动输入接口RGH_CELL / RGL_CELL = 2.5Ω：门极串联电阻占位RGH_PD / RGL_PD = 10kΩ：Gate-Kelvin Source 下拉CDCELL_HF = 100nF / 1200V：输出单元高频母线旁路占位
检查结果：原理图接口网络已建立；当前报错主要是 PCB 尚未为新增模块接口放置/布线产生的 airwires，以及已有布局中的一个 overlapping copper。下一步应导入/创建 CI90N120SM4 四引脚器件 后，把这些接口替换为真实 MOSFET 符号并继续完善栅极驱动和保护。
备选方案 Microchip MSC025SMA120B4N怎么样
Thought for 33 sec
我会把 Microchip MSC025SMA120B4N 作为非国产备选来评估：重点核对耐压、电流、RDS(on)、Qg、Kelvin 源极、驱动电压和开关损耗，再判断是否适合作为临时原理图器件或最终备选。
Working for 2 days 17 hrs...
Thought for 6 sec
Reading MSC025SMA120B4N datasheet for absolute maximum ratings VDS VGS continu.
Reading MSC025SMA120B4N datasheet for electrical characteristics RDS on gate t.
Reading MSC025SMA120B4N datasheet for switching characteristics turn on energy.
Reading MSC025SMA120B4N datasheet for pin configuration package TO-247-4 Kelvi...
与外界的联系只有供电输入，信号输入输出
Pulling up the datasheet...
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Preliminary Component Selection
Selection Rule
Use China-made / China-supply-chain parts when they satisfy electrical, thermal, safety, and reliability requirements. For high-voltage and safety-critical parts, datasheet ratings and safety certification override sourcing preference.
Library Search Findings
Output Power Switches
Initial Flux library searches did not find an exact 1200 V Tokmas CI90N120SM4 / LCSC C5364637 part. The exact part must be imported/created before final schematic capture. A non-China fallback with a ready Flux footprint exists, Microchip MSC025SMA120B4N, but it does not meet the China-made preference and is therefore not selected as the primary device.
Selected Tokmas / LCSC 1200 V SiC MOSFET
Primary Selected Device: Tokmas CI90N120SM4
Table
| Parameter | Value |
|---|---|
| Manufacturer | Tokmas / 托克马斯 |
| MPN | CI90N120SM4 |
| LCSC Part Number | C5364637 |
| Package | TO-247-4L |
| Device type | N-channel SiC MOSFET |
| VDS max | 1200 V |
| Continuous drain current | 90 A at TC=25°C, 60 A at TC=100°C |
| Pulsed drain current | 250 A |
| RDS(on) | 27 mΩ typ, 38 mΩ max at VGS=20 V, ID=50 A |
| Recommended VGS | -5 V / +20 V |
| Absolute VGS max | -10 V / +25 V |
| VGS(th) | 2.0 V min, 2.5 V typ, 4.0 V max |
| Total gate charge Qg | 185 nC at VDS=800 V, VGS=-5/+20 V, ID=50 A |
| Ciss / Coss / Crss | 4700 pF / 220 pF or 231 pF / 42.8 pF |
| Switching energy | EON 2.2 mJ, EOFF 0.5 mJ at VDS=800 V, ID=50 A, RG=2.5 Ω |
| Thermal resistance | RθJC 0.24°C/W typ, 0.27°C/W max |
| Junction temperature | -55°C to +150°C |
| Pinout | Pin 1 Drain, Pin 2 Source, Pin 3 Kelvin Source, Pin 4 Gate |
| LCSC stock observed | Low stock: 2 units reported at time of lookup |
Why CI90N120SM4 is preferred over CI90N120SM
CI90N120SM is the TO-247-3 version and had better observed stock, but CI90N120SM4 has a Kelvin source terminal. For a high-slew-rate, 500 kHz-class multilevel output stage, the Kelvin source is important because it separates gate-drive return from the high-current power source lead, reducing common-source inductance, gate ringing, false turn-on, and switching loss sensitivity.
Backup Device: Tokmas CI90N120SM
Table
| Parameter | Value |
|---|---|
| MPN | CI90N120SM |
| LCSC Part Number | C5364636 |
| Package | TO-247-3 |
| VDS max | 1200 V |
| Continuous drain current | 90 A at TC=25°C, 60 A at TC=100°C |
| RDS(on) | 27 mΩ typ, 38 mΩ max |
| Qg | 185 nC |
| Pinout | Pin 1 Gate, Pin 2 Drain, Pin 3 Source, tab/drain pin 4 Drain |
| LCSC stock observed | 125 units reported at time of lookup |
Use CI90N120SM only if CI90N120SM4 is unavailable or cannot be imported with a correct 4-lead footprint.
Suitability Check Against Project Requirement
The device voltage and current ratings exceed the amplifier target of ±1000 V peak and ≥10 A peak output current when used in an appropriately derated multilevel topology. However, the switching-loss data shows that hard-switching this device at hundreds of kHz with large voltage/current overlap is not acceptable: the datasheet switching-energy test at 800 V and 50 A gives EON+EOFF ≈ 2.7 mJ. At 500 kHz this would imply extreme loss if operated as a hard-switched single-stage bridge.
Therefore the selected device is suitable only if the output stage uses one or more of the following:
- Multilevel/cascaded cells to reduce per-device voltage swing.
- Soft-switching or resonant/transition-assisted modulation where possible.
- Carefully limited dv/dt and current as already specified.
- Very low-inductance gate and power layout using the Kelvin source pin.
- Thermal design based on actual switching waveform and duty cycle, not only DC current rating.
Isolated Gate Driver Candidates
Flux library candidates:
Table
| Candidate | Notes | Status |
|---|---|---|
| STGAP2SCM | Galvanically isolated 4 A single gate driver with Miller clamp, SOIC-8; LCSC availability shown in Flux result | Candidate for per-switch isolated drive |
| 2ED1324S12P | 1200 V half-bridge gate driver with active Miller clamp/OCP/SCC/bootstrap diode | Strong function match, but not China-made and no LCSC availability shown |
| STGAP1AS | Isolated 5 A advanced gate driver with DESAT/UVLO/OVLO/SPI | Feature-rich candidate, availability not shown |
For CI90N120SM4, the selected gate driver must support -5 V / +20 V gate drive or an equivalent safe bias strategy, local isolated supply, Miller clamp or negative turn-off, and very short gate loop routing to the Kelvin source pin.
Waveform / Control Candidates
Flux library candidates:
Table
| Candidate | Notes | Status |
|---|---|---|
| DAC80501ZDGSR | 16-bit single-channel DAC, LCSC/Mouser availability shown | Candidate for low-voltage reference / waveform path |
| DAC43401DSGRQ1 | Compact DAC, LCSC part shown | Candidate for control/reference generation |
| AD7606BSTZ | 8-channel 16-bit ADC, 200 kS/s, LCSC availability shown | Useful for monitoring, too slow for direct 500 kHz waveform feedback if sampled full-band |
A dedicated high-speed ADC/FPGA/DSP selection is still required for closed-loop arbitrary waveform control at 500 kHz.
Mains Input / Protection Candidates
Flux library candidates:
Table
| Candidate | Notes | Status |
|---|---|---|
| V275LA10P | 275 VAC MOV, LCSC listed | Candidate surge protection for 220 VAC mains |
| CM3440Z171R-10 | 20 A common-mode choke/filter, 170 ohm @ 100 MHz | Candidate EMI common-mode filter, safety ratings must be verified |
| GBP310(70MIL) | Bridge rectifier candidate | Current rating likely below final need; exact 600 V / 10 A bridge not found in returned results |
Updated Design Decision
Select Tokmas CI90N120SM4 as the primary 1200 V SiC MOSFET for the multilevel output-cell design because it is China-supply-chain, LCSC-listed, has a TO-247-4 Kelvin-source package, and has sufficient voltage/current margin. Do not finalize the power-cell schematic until the exact part is imported/created in Flux with correct pinout and TO-247-4L footprint.
Required Before Final Schematic
- Import/create Tokmas CI90N120SM4 with 4 terminals: D, S, KS, G.
- Verify or create TO-247-4L footprint with correct pin order: Pin 1 Drain, Pin 2 Source, Pin 3 Kelvin Source, Pin 4 Gate.
- Confirm available stock or procure samples; observed LCSC stock was very low.
- Verify isolated gate-driver supply design for -5 V / +20 V gate drive.
- Define number of output cells and per-cell bus voltage to keep switching losses practical.
- Simulate representative multilevel switching waveforms with 2.5 nF load before PCB layout.
Selection Rule
Library Search Findings
Output Power Switches
Selected Tokmas / LCSC 1200 V SiC MOSFET
Primary Selected Device: Tokmas CI90N120SM4
Why CI90N120SM4 is preferred over CI90N120SM
Backup Device: Tokmas CI90N120SM
Suitability Check Against Project Requirement
Isolated Gate Driver Candidates
Waveform / Control Candidates
Mains Input / Protection Candidates
Updated Design Decision
Required Before Final Schematic
