The LM5166 is a compact, easy-to-use, 3-V to 65-V, ultra-low IQ synchronous buck converter with high efficiency over wide input voltage and load current ranges. With integrated high-side and low-side power MOSFETs, up to 500 mA of output current can be delivered at fixed output voltages of 3.3 V or 5 V, or an adjustable output. The converter is designed to simplify implementation while providing options to optimize the performance for 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. Both control schemes do not require loop compensation while 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 setpoint 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 LM5166 is available in a VSON-10 package with 0.5-mm pin pitch. To create a custom regulator design, use the LM5166 with WEBENCH®_Power Designer_.
● Wide 3-V to 65-V Input Voltage Range
● 9.7-µA No-Load Quiescent Current
● –40°C to 150°C Junction Temperature Range
● Meets EN55022 and CISPR 22 EMI Standards
● Integrated 1-Ω PFET Buck Switch
● Supports 100% Duty Cycle for Low Dropout
● Integrated 0.5-Ω NFET Synchronous Rectifier
● Eliminates External Schottky Diode
● Programmable Peak Current Limit Supports:
● 500 mA, 300 mA, or 200 mA Loads
● Fixed (5 V, 3.3 V) or Adjustable VOUT Options
● Two Selectable Control Options:
● COT for Nearly Constant Frequency
● PFM for Maximum Efficiency
● 1.223-V ±1.2% Internal Voltage Reference
● Switching Frequency up to 600 kHz
● 900-µs Internal or Externally Adjustable Soft-Start
● Diode Emulation and Pulse Skipping for Ultra-High Light-Load Efficiency
● No Loop Compensation or Bootstrap Components
● Precision Enable/Input UVLO with Hysteresis
● Open-Drain Power Good Indicator
● Thermal Shutdown Protection with Hysteresis
● Pin-to-pin Compatible with the LM5165
● 10-Pin, 3-mm × 3-mm VSON Package