36-V Regulators enable Low EMI and Deep Drop-out Conditions

Texas Instruments (TI) today introduced two 36-V, 2.1-MHz synchronous buck regulators that eliminate switch-node ringing to reduce electromagnetic interference (EMI), improve power density, and operate in deep drop-out conditions. The 2.5-A LM53625-Q1 and 3.5-A LM53635-Q1 regulators are designed for high-voltage dc-dc step-down applications such as automotive infotainment, high-end cluster, advanced driver assistance systems (ADAS) and body power-supply systems. Wettable flank packaging enables optical inspection to reduce manufacturing costs.

Switch node ringing is inherent in all switch-mode power supplies. By reducing parasitic inductance and capacitance in the LM53625-Q1 and LM53635-Q1 regulators, these power solutions lower noise and EMI emissions by up to 15 dB at the system level, which requires less external EMI filtering, saves printed circuit board area and simplifies compliance with CISPR 25 automotive EMI requirements.

LM53625-Q1 and LM53635-Q1 key features and benefits: Wide 3.5-V to 42-V operating range handles start-stop and load-dump conditions for 12-V lead acid automotive batteries. Provide up to 93 percent efficiency at 2.1-MHz operation to support compact and high-temperature conditions in automotive applications. Low 18-uA quiescent current (IQ) in standby extends battery life in "always on" applications. Deep drop-out performance of less than 0.6 V under full load and temperature conditions enables compliance with stringent cold-crank and start-stop conditions, saving system cost and solution size.

The new dc-dc regulators are available in volume now from TI and its authorized distributors. Offered in a 22-pin, 4-mm-by-5-mm very thin quad flat no-lead (VQFN) package, the LM53625-Q1 is priced at US$2.79 in 1,000-unit quantities and the LM53635-Q1 is priced at US$3.22.