Motor Driver IC Integrating Dead Time Generation
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Solution Overview
Problem
Conventional semiconductor devices for driving three-phase motors face issues with noise-induced short circuits between top and bottom arms, high temperature malfunctions, and the need for large, costly packages due to the generation of six control signals and dead time, which complicates miniaturization and cost reduction in applications like fan motors.
Innovation Solution
A semiconductor device with six switching elements and three control signal input terminals, sealed as a single package, generates six control signals with a dead time function internally, reducing the need for external control signal generation and minimizing noise susceptibility by shortening signal paths, thus preventing top-bottom arm short circuits and allowing for miniaturization and cost reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If six control signals are generated externally using a separate controlling semiconductor device, then the motor driving function is achieved, but the device size increases and noise susceptibility rises
Solution Approach 1:
The patent combines the motor driving semiconductor chip with the dead time generating function into a single integrated package. The control signal generating circuit is formed within the same package as the switching elements, eliminating the need for a separate controlling semiconductor device. This integration reduces the overall device size and minimizes the length of external wiring, thereby reducing noise susceptibility and improving reliability.
2Ease of operation
If external wiring is used to connect controlling device to motor driver, then control signals are transmitted, but noise-induced short circuits occur between top and bottom arms
Solution Approach 1:
The control signal generating circuit is integrated within the same package as the switching elements, eliminating external wiring between the controlling device and motor driver. The dead time generating function is implemented using internal wiring only, which dramatically reduces noise susceptibility and prevents noise-induced short circuits between top and bottom arms.
3Reliability
If separate controlling semiconductor device is used, then dead time generation is achieved, but temperature differences cause operational issues
Solution Approach 1:
The control signal generating circuit and switching elements are housed in the same package, ensuring they operate at similar temperatures. This thermal coupling eliminates operational issues caused by temperature differences between separate devices, improving reliability in high-temperature environments.
Data Source
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AI summary
In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device (10, 10M, 10R, 10P) for driving a motor, being sealed with resin as one package and comprising: six switching elements (T1 - T6) for driving a three-phase motor (5); three output terminals (P9, P10, P11) for outputting voltages to the three-phase motor; at least one driving circuit (KT, KB) for driving the six switching elements; three control signal input terminals (P21, P22, P23); and a function (LG6, Fig. 2, Fig. 4) of generating six control signals (VUT, VVT, VWT, VCTB, VVB, VWB) for control of the six switching elements based on three control signals (VU, VV, VW) inputted through the three control signal input terminals.