Low Iq 65-V Micro-Power Buck Converters

Texas Instruments (TI) today introduced two 65-V, 150-mA synchronous dc-dc buck converters claiming the industry's lowest 10.5-uA quiescent current (IQ) 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 (VIN) range and dual control modes for optimizing efficiency and printed circuit board (PCB) area.

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 150 degrees C for higher temperature environments. The LM5165-Q1 is AEC-Q100 qualified for automotive applications.

LM5165 and LM5165-Q1 key features and benefits include: Low 10.5-uA standby IQ (operating with no load) enables 90-percent conversion efficiency at 1-mA to 10-mA loads to extend battery life in "always on" 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. Fixed 3.3-V and 5-V options eliminate external feedback resistor dividers to lower bill of materials. And programmable current limit optimizes inductor size and cost.

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.