First multi-phase current controller handles 500W per phase

March 21, 2017 // By Christoph Hammerschmidt
The introduction of the 48 V electrical system in vehicles to complement the existing 12 V system entails that between the two voltage levels connections have to be created – typically as bi-directional DC/DC converters. This application is Texas Instruments targeting with its LM5170-Q1 current controllers. As an industry’s first, the device is implemented as a multi-phase circuit.

The LM5170-Q1, designed to transfer 500W between the two voltage levels, is a highly-integrated analogue controller. It uses an average current mode control method that avoids the problems of today's purely digital controls with a high level of component complexity.

For the management of this double wiring system design engineers typically resort to digital control procedures. These, however, require several discrete components such as, for example, current measuring amplifiers, gate drivers and protective modules, and are accordingly bulky and expensive. To solve this problem while improving performance and system reliability, TI offers a combined architecture. In this case, a microcontroller is responsible for the superior intelligent management, while the highly integrated analog controller LM5170-Q1 takes over the actual power conversion.

The LM5170-Q1 features a special design to optimize system costs and performance: The chip’s Average Current Mode control method improves performance, simplifies implementation, and reduces costs. Another property of the LM5170-Q1 is its high accuracy: The 1-percent accurate bidirectional current control of the controller ensures accurate power transfer. The energy efficiency is specified as 97% and more – a very high value.

Other features include high accuracy as the controller monitors the current with an accuracy of up to 99%. For deployment in vehicles, the LM5170-Q1 is AEQ-Q100-qualified.

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