The highly integrated LM5170-Q1 analogue controller features an average current-mode control method that overcomes the challenges of high-component-count, full digital control schemes.
48-V battery and standard 12-V automotive batteries in HEVs are typically managed using a digital control scheme, which includes multiple discrete components such as current-sense amplifiers, gate drivers and protection circuits. These full digital control schemes are bulky and expensive. To solve this challenge while improving performance and system reliability, TI offers a mixed architecture in which the microcontroller handles higher-level intelligent management, and the highly integrated LM5170-Q1 analogue controller provides the power conversion.
The LM5170-Q1’s average current-mode control method improves performance, simplifies implementation and reduces cost, described in “Selecting a bidirectional converter control scheme”. The controller’s 1%-accurate bidirectional current regulation ensures precise power transfer, with greater than 97 percent efficiency and current monitoring of up to 99% accuracy. Integrated 5-A peak half-bridge gate drivers offer high power capability, and diode emulation mode of the synchronous rectifier MOSFETs prevents negative current and enhances light load efficiency. The LM5170-Q1 is AEC-Q100 qualified.
The LM5170-Q1 in a 48-pin, 9 x 9-mm quad flat package (QFP) is priced at $5.84 (1,000). Support includes the LM5170EVM-BIDIR evaluation module, PSpice transient model and LM5170-Q1 quick-start DC/DC synchronous buck converter design tool.
TI has a blog post, “Interconnecting automotive 48V and 12V rails in dual battery systems” on the challenges of designing a power supply for hybrid electric vehicles.