LM5165 Synchronous Buck Converters

LM5165 Synchronous Buck Converters

Texas Instruments' LM5165 converters are compact, easy-to-use, 3 V to 65 V, ultra-low IQ synchronous buck converters with high efficiency over wide input voltage and load current ranges. With integrated high-side and low-side power MOSFETs, up to 150 mA of output current can be delivered at fixed output voltages of 3.3 V or 5 V, or at an adjustable output. The converters are designed to simplify implementation while providing options to optimize the performance of the target application. Pulse frequency modulation (PFM) mode is selected for optimal light-load efficiency or constant on-time (COT) control for nearly constant operating frequency. Neither control scheme requires loop compensation while still providing excellent line and load transient response and short PWM on-time for large step-down conversion ratios.

The high-side P-channel MOSFET can operate at 100% duty cycle for lowest dropout voltage and does not require a bootstrap capacitor for gate drive. Also, the current limit set point is adjustable to optimize inductor selection for a particular output current requirement. Selectable/adjustable startup timing options include minimum delay (no soft start), internally fixed (900 µs), and externally programmable soft start via an external capacitor. An open-drain PGOOD indicator can be used for sequencing and output voltage monitoring. The LM5165 converters are qualified to automotive AEC-Q100 Grade 1 and are available in a VSON-10 package with 0.5 mm pin pitch.

Features
  • Wide input voltage range of 3 V to 65 V
  • Fixed (3.3 V, 5 V) or adjustable output voltages
  • Maximum output current as high as 150 mA
  • 10.5 µA no load quiescent current
  • -40°C to 150°C junction temperature range
  • Selectable PFM or COT mode operation
  • Switching frequency as high as 600 kHz
  • Diode emulation mode and pulse skipping for ultra-high light-load efficiency performance
  • Integrated 2 Ω PMOS buck switch
    • Supports 100% duty cycle for low dropout
  • Integrated 1 Ω NMOS synchronous rectifier
    • Eliminates external rectifier diode
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