LM5166XDRCR

The LM5166 is an easy-to-use, compact 3V to 65V, ultra-low IQ synchronous buck converter that provides high efficiency over a wide input voltage and load current range. The device integrates high-side and low-side power metal-oxide-semiconductor field-effect transistors (MOSFETs) and can deliver an output current of up to 500mA. The output voltage is available in both fixed (3.3V or 5V) and adjustable options. This converter is designed to simplify implementation while optimizing the performance of target applications. The pulse frequency modulation (PFM) mode ensures optimal efficiency under light load conditions, and the constant on-time (COT) control enables an approximately constant operating frequency. Both control schemes do not require loop compensation and can achieve excellent line and load transient responses and short pulse-width modulation (PWM) on-times for high step-down conversion ratios. The high-side P-channel MOSFET can operate at a 100% duty cycle to ensure the lowest dropout voltage and does not require a bootstrap capacitor for gate drive. Additionally, the current limit setting can be adjusted to optimize inductor selection to meet specific load current requirements. The optional and adjustable startup timing options include the shortest delay (no soft start), an internal fixed value (900μs), and soft start that can be externally programmed using a capacitor. An open-drain PGOOD indicator can be used for sequencing, fault reporting, and output voltage monitoring. The LM5166 is available in a 10-pin VSON package with a 0.5mm pin pitch.

Applications

• Factory and building automation
• Automotive and battery-powered applications
• High-voltage LDO replacement
• Low-power bias supply

Key features

• 3V to 65V wide input voltage range
• 9.7μA no-load quiescent current
• -40°C to 150°C junction temperature range
• Fixed (3.3V, 5V) or adjustable output voltage options
• Compliant with EN55022/CISPR 22 EMI standards
• Integrated 1Ω PFET buck switch with 100% duty cycle support for low dropout
• Integrated 0.5Ω NFET synchronous rectifier, no external Schottky diode required
• Programmable peak current limit: 500mA, 300mA, or 200mA load
• Selectable PFM or COT mode operation
• 1.223V ±1.2% internal voltage reference
• Switching frequency up to 600kHz
• 900μs internal or externally adjustable soft-start
• Diode emulation and pulse-skipping mode for ultra-high efficiency at light load
• No loop compensation or bootstrap components required
• Precision enable and input UVLO with hysteresis
• Open-drain power-good indicator
• Thermal shutdown protection with hysteresis
• Pin-to-pin compatible with LM5165
• 10-pin 3mm×3mm SON package
• Create custom regulator designs using WEBENCH Power Designer