LM51261AQRHBRQ1

LM51261A-Q1 is a synchronous boost controller with an I2C interface. The device provides regulated output when the input voltage is lower than or equal to the output voltage, and supports input-to-output bypass mode to reduce power consumption. It can be combined and stacked with LM51251A-Q1 for 3-phase operation. The output voltage can be dynamically set via analog or digital ATRK/DTRK functions or I2C programming. After startup, the minimum supported input voltage is 2.5V; when VBIAS drops below 4.5V, the internal VCC supply automatically switches from VBIAS to VOUT. The fixed switching frequency can be set between 100kHz and 2.2MHz via a resistor on the RT pin or a SYNCIN clock. The switching mode — FPWM or diode emulation — can be changed during operation. The device integrates peak current limiting, average input current limiting, average inductor current monitoring, overvoltage and undervoltage protection, and thermal shutdown to protect the device and application.

Applications

• High-end audio power supplies
• Voltage regulator modules
• Start-stop applications

Key features

• AEC-Q100 qualified for automotive applications
• Temperature Grade 1: TA = -40℃ to +125℃
• Functional Safety support with documentation to assist functional safety system design
• Input voltage range: 4.5V to 42V
• Minimum input voltage down to 2.5V when VBIAS ≥ 4.5V or VOUT ≥ 6V
• Output voltage range: 6V to 60V
• Output voltage adjustable in 1V steps via resistor or I2C
• Programmable slew rate via I2C
• Integrated feedback resistors with 2% accuracy
• Bypass operation supported when VI > VOUT
• Dynamic output voltage tracking
• Digital PWM tracking (DTRK)
• Analog tracking (ATRK)
• Overvoltage protection with selectable thresholds: 64V, 50V, 35V, 28.5V
• Shutdown quiescent IQ as low as 2μA
• Operating quiescent IQ as low as 1mA
• 3-phase operation with LM51251A-Q1
• Switching frequency range: 100kHz to 2.2MHz
• External clock synchronization (SYNCIN)
• Dynamically selectable switching modes (FPWM, diode emulation)
• Spread spectrum (DRSS)
• I2C interface with 8 selectable addresses
• I2C programmable dead time: 14ns to 200ns
• Current sense resistor or DCR sensing
• Average inductor current monitoring
• Average input current limiting
• Programmable current limit
• Selectable blanking time
• nFAULT indication
• Programmable input UVLO
• Leadless QFN-32 package with wettable flanks