Introduction

A Silan IPM brings the three-phase power stage, the high-voltage gate drive and the protection together in one package, which simplifies the drive design but still leaves several decisions to the designer: the control supply, the current-sense resistor, the protection thresholds and the thermal path. This application note explains those decisions for compact appliance, pump and industrial drives, so a design moves quickly from concept to a reliable board.

Control Supply and Interface

A Silan IPM is designed to be driven directly by a microcontroller. It uses a single 15 V control supply and accepts a 3.3 V or 5 V logic input, so it connects without level shifting. The control supply must be clean and well decoupled close to the module, because noise on the supply can disturb the gate drivers. The module's bootstrap supply monitoring guards the high-side drive, so the designer does not need a separate isolated supply for the upper switches.

Input Logic and Dead Time

Inside the IPM, the dead time between the high-side and low-side switches is fixed and factory-tuned, so the designer does not generate it in software. This removes a common source of shoot-through failures in discrete designs and simplifies the microcontroller code. The input signals still need to respect the module's minimum pulse timing, so check the datasheet for the switching timing and the propagation delay before finalizing the control loop.

Overcurrent Protection

An IPM detects overcurrent by sensing the current through the low-side switches. The designer selects an external current-sense resistor that sets the trip level. Size the resistor so the trip current sits above the motor's peak operating current with margin, but below the module's safe limit. A trip that is too low nuisance-trips on normal acceleration; a trip that is too high does not protect the module. After a trip, the module asserts a fault and latches off until the fault is cleared, so the controller should read the fault and shut down the motor cleanly before re-enabling.

Thermal Shutdown

The module also monitors its own temperature and shuts down if it exceeds a safe threshold. A thermal-shutdown event means the thermal design or the load is outside the intended range, so treat it as a design signal rather than a transient and improve the heatsink or reduce the load. The thermal-shutdown protection is a last line of defence, not a normal operating condition.

Board Layout

Even with integrated protection, layout decides reliability and EMI. Mount the IPM flat against a clean, flat heatsink with a thin, uniform interface, and verify the case temperature at full load. Keep the DC-link capacitor close to the module power terminals to minimize the commutation loop, route the current-sense resistor with short leads, and keep high-current paths away from the low-level control signals. These habits keep EMI low and the protection reliable.

Cooling and Mounting

The IPM must dissipate the inverter loss through its case, so the thermal interface and the heatsink are as important as for a discrete design. Use the specified mounting torque, avoid an uneven or contaminated interface, and confirm the case temperature under the worst-case load and ambient. A marginal thermal path does not necessarily destroy the part because the module protects itself, but it limits output and hurts reliability.

Scaling Across the Family

The Silan IPM family shares a common interface across 10 A, 15 A, 20 A and 30 A ratings, so a design can scale from a small appliance to a larger compressor without changing the control side. When you move to a higher rating, re-check the current-sense resistor, the DC-link capacitor and the thermal design, but the microcontroller interface and firmware stay essentially the same. That consistency shortens development and reduces the risk of a redesign when the product range grows.

Conclusion

A Silan IPM removes most of the power-stage engineering from the designer's task, leaving the control supply, the trip level and the thermal path to specify. Get those right, respect the layout and thermal rules, and the result is a compact, reliable drive that reaches production quickly.