Description

The PMP9458 reference design is a conducted EMI optimized 2-layer board power supply for automotive cluster units. The power supply has two buck regulators in cascaded connection: the first stage buck generates a 5V: 2A output using the LM26003: and the second stage generates two outputs of 2.8V: 1.5A and 1.8V: 2A using the LM26420 (The max output power in total is 14W). The LM26003 is a wide Vin non-sync buck regulator: and the LM26420 is a 5V input dual 2A: high frequency sync buck regulator. They both have automotive grade versions: qualified in AEC-Q100 Grade 1. The input voltage range of the design is 6.5V to 38V making it suitable for automotive 12V battery systems. The 2-layer board design has the PCB layout optimized and adds an input filter stage to improve the conducted EMI performance. The board is tested under the automotive EMC standard: CISPR 25: and its conducted emissions are in compliance with the CISPR 25 Class 5 requirements.