Synchronous Buck Converter Reference Design for Infotainment Applications
Description
This reference design is a Synchronous Buck Converter circuit using the LM63625-Q1 controller integrated circuit (IC). The design accepts an input voltage of 9.8 VIN to 16 VIN and provides a regulated output voltage of 9.3 VOUT capable of delivering up to 2.1 A of current. The design is built on a 4-layer FR-4 PCB, with 1 oz copper for each of the four layers. The board is 29.2 mm × 12.5 mm. See LM636xx-Q1 Functional Safety FIT Rate, FMD, and Pin FMA for any safety concerns.
Features
- Very small design size with single-sided component assembly
- Regulator includes integrated FETs
- High efficiency
- Optimized for automotive applications
- Regulator features spread-spectrum switching (dithering) for improved EMI performance
Applications
Waveforms gathered for Section 3.4 (Start-up and Shutdown) were performed with 6 × 22-μF output capacitors installed and with a 100-kΩ top feedback divider resistor and 12.1-kΩ bottom feedback divider resistor. All other tests were performed using the 2 × 22-μF output capacitors and 24.9-kΩ top feedback divider resistor and 3.01-kΩ bottom feedback divider resistor.
No significant change is anticipated during start-up, except for a lower input current during the soft-start period when using 2 × 22-μF output capacitors.
No significant change is anticipated during shutdown, except for a faster output voltage decay when using 2 × 22-μF output capacitors.
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