Designed for factory automation and automotive sensor applications requiring high efficiency, two 65V, 150mA synchronous DC/DC buck converters have been unveiled by Texas Instruments. The industrial-grade LM5165 and automotive-grade LM5165-Q1 micro-power step-down regulators feature a 10.5µA quiescent current, claimed to be the industry's lowest.
The regulators feature a wide input voltage range and dual control modes for optimising efficiency and PCB area. By using the regulators together with TI's WEBENCH Power Design tool, engineers can get their factory and process automation designs to market faster.
The wide 3 to 65V operating range enables the LM5165 and LM5165-Q1 micro-power regulators to handle the highest transients in industrial sensor and PLC applications, as well as start-stop and load-dump conditions for 12/24V lead-acid and emerging 48V Li-ion automotive batteries. Integrated dual MOSFETs reduce PCB area, while a programmable current-limit scheme reduces inductor size. Both regulators operate at junction temperatures up to 150°C for higher temperature environments. The LM5165-Q1 is AEC-Q100 qualified for automotive applications.
The regulator's low standby quiescent current (operating with no load) enables 90% conversion efficiency at 1 to 10mA loads to extend battery life in 'always on' applications. 100% duty cycle enables low-dropout operation, while a P-channel high-side MOSFET eliminates the bootstrap diode and capacitor. The fixed 3.3 and 5V options eliminate external feedback resistor dividers to lower BoM while the programmable current limit optimises inductor size and cost. A pulse frequency modulation control mode enables the highest efficiency power supply design, while a constant on-time control mode provides higher output current and better EMI performance.
The regulators are available in volume now from TI and its authorised distributors. Packaged in a 10-pin, 3x3mm VSON package, the industrial-grade LM5165 is priced at $1.35 and the automotive-grade LM5165-Q1 at $1.58, both in 1,000 unit quantities. Evaluation modules for both regulators are also available.