qwen-spice-lora-v2

Qwen2.5-Coder-3B SPICE Netlist Generator (LoRA v2)

Fine-tuned LoRA adapter on unsloth/qwen2.5-coder-3b-instruct-bnb-4bit that generates simulation-ready SPICE netlists from natural language circuit descriptions.

Trained 2x faster with Unsloth

<img src="https://raw.githubusercontent.com/unslothai/unsloth/main/images/unsloth%20made%20with%20love.png" width="200"/>

• Developed by: ADI2005
• License: apache-2.0
• Finetuned from: unsloth/qwen2.5-coder-3b-instruct-bnb-4bit

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Model Details

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What It Does

Given a plain English description of an analog or digital circuit, the model generates a complete, valid SPICE netlist including:

• Component definitions and node connections
• .MODEL statements for transistors, diodes, and MOSFETs
• Appropriate analysis commands (.AC, .DC, .TRAN, .OP)
• .END termination

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Validation Results

Tested on 5 circuit types after training — 5/5 passed PySpice syntax validation:

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Usage

from unsloth import FastLanguageModel

model, tokenizer = FastLanguageModel.from_pretrained(
    model_name="ADI2005/qwen-spice-lora-v2",
    max_seq_length=2048,
    dtype=None,
    load_in_4bit=True,
)
FastLanguageModel.for_inference(model)

SYSTEM_PROMPT = """You are an expert analog circuit designer and SPICE netlist generator. 
When given a circuit description, you generate a complete, valid, simulation-ready SPICE netlist 
compatible with ngspice. Always include component definitions, node connections, model statements 
where needed, and an analysis command. End every netlist with .END"""

messages = [
    {"role": "system", "content": SYSTEM_PROMPT},
    {"role": "user", "content": "Design a low-pass RC filter with a cutoff frequency of 1kHz."},
]

input_ids = tokenizer.apply_chat_template(
    messages, tokenize=True, add_generation_prompt=True, return_tensors="pt"
).to("cuda")

outputs = model.generate(
    input_ids=input_ids,
    max_new_tokens=512,
    temperature=0.1,
    do_sample=True,
    pad_token_id=tokenizer.eos_token_id,
)

response = tokenizer.decode(outputs[0][input_ids.shape[1]:], skip_special_tokens=True)
print(response)

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Training Dataset

Trained on ADI2005/spice-circuits-finetune-v2 — 7,410 instruction-output pairs covering 7 circuit families:

• Resistive networks
• RC circuits (low-pass, high-pass, band-pass filters)
• RLC circuits
• Diode circuits (rectifiers, clippers, clamps)
• BJT amplifiers and switches
• MOSFET circuits (CMOS logic, amplifiers)
• Op-amp circuits (inverting, non-inverting, integrators, comparators)

All entries validated with PySpice before training.

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Limitations

• Component values are not always calculated precisely for a given specification (e.g., exact cutoff frequency). The topology will be correct but values may need tuning.
• Best results on circuit types covered by the training set. Novel or exotic topologies may produce lower quality outputs.
• Designed for ngspice compatibility. LTSpice-specific syntax is not guaranteed.

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Roadmap

• V3 dataset with spec-to-value calculated entries for filter and amplifier circuits
• PySpice validation + retry loop at inference time
• RAG layer for out-of-distribution prompts
• Schematic generation via Weave integration