65-V micro-power buck converters optimize light-load efficiency

Texas Instruments today introduced two 65-V, 150-mA synchronous DC/DC buck converters with the industry’s lowest 10.5-uA quiescent current (I_Q) for powering factory automation and automotive sensor applications requiring high efficiency. The industrial-grade LM5165 and automotive-grade LM5165-Q1 micro-power step-down regulators feature a wide input voltage (V_IN) range and dual control modes for optimizing efficiency and printed circuit board (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-V to 65-V operating range enables the LM5165 and LM5165-Q1 micro-power regulators to handle the highest transients in industrial sensor and programmable logic controller (PLC) applications, as well as start-stop and load-dump conditions for 12-V/24-V lead-acid and emerging 48-V lithium-ion automotive batteries. Integrated dual metal-oxide semiconductor field-effect transistors (MOSFETs) reduce PCB area, while a programmable current-limit scheme reduces inductor size. Both regulators operate at junction temperatures up to 150ºC for higher temperature environments. The LM5165-Q1 is AEC-Q100 qualified for automotive applications.

LM5165 and LM5165-Q1 key features and benefits

• Low 10.5-uA standby I_Q (operating with no load) enables 90-percent conversion efficiency at 1-mA to 10-mA loads to extend battery life in “always on” applications. Read the blog post “Powering smart sensor transmitters in industrial applications.”
• 100-percent duty cycle enables low-dropout operation, while a P-channel high-side MOSFET eliminates the bootstrap diode and capacitor.
• Dual-mode operation: a pulse frequency modulation (PFM) control mode enables the highest efficiency power supply design, while a constant on-time (COT) control mode provides higher output current and better electromagnetic interference (EMI) performance. Read the application note “Simple success with conducted EMI from DC/DC converters.”
• Fixed 3.3-V and 5-V options eliminate external feedback resistor dividers to lower bill of materials (BOM).
• Programmable current limit optimizes inductor size and cost.

The LM5165 and LM5165-Q1 join TI’s family of wide V_IN DC/DC step-down regulators that include the LM5017, LM5160 and TPS54062. Get more information on TI’s high-performance DC/DC converter portfolio for any power supply design.

Availability, packaging and pricing

The regulators are available in volume now from TI and its authorized distributors. Packaged in a 10-pin, 3-mm-by-3-mm VSON, the industrial-grade LM5165 is priced at US$1.35 in 1,000-unit quantities and the automotive-grade LM5165-Q1 is priced at US$1.58. 

Texas Instruments
www.ti.com