LM5123QRGRRQ1

The LM5123-Q1 is a wide input range synchronous boost controller with peak current mode control. The device features a low shutdown IQ and low IQ sleep mode to minimize battery drain under no-load and light-load conditions. It also supports an ultra-low IQ deep sleep mode with bypass mode, eliminating the need for an external bypass switch when the supply voltage exceeds the boost output regulation target. The output voltage can be dynamically programmed using the tracking function. The wide input range supports automotive cold crank and load dump. When BIAS is at or above 3.8V, the minimum input voltage can be as low as 0.8V. The switching frequency can be dynamically programmed via an external resistor over a range of 100kHz to 2.2MHz. The 2.2MHz switching frequency minimizes AM band interference while enabling a small solution size and fast transient response. Compared to a converter architecture, the controller architecture simplifies thermal management under harsh ambient temperature conditions. The device incorporates built-in protection features such as constant peak current limiting across the VIN range, overvoltage protection, and thermal shutdown. External clock synchronization, programmable spread spectrum modulation, and a leadless package with ultra-low parasitics help reduce EMI and avoid crosstalk issues. Additional features include line UVLO, FPWM, diode emulation, DCR inductor current sensing, programmable soft-start, and a power-good indicator.

Applications

• Automotive audio power supply with tracking function
• Automotive LED bias power supply
• Automotive HVAC controller power supply
• Automotive motor power supply

Key features

• AEC-Q100 qualified for automotive applications – Temperature Grade 1: -40°C to +125°C, TA
• Functional safety support
• Documentation to assist functional safety system design for automotive battery-powered applications with wide operating voltage range
• 3.8V to 42V input voltage operating range
• Dynamically programmable VOUT of 5V to 20V or 15V to 57V
• Minimum boost input of 0.8V when BIAS voltage ≥3.8V
• Bypass operation when VSUPPLY > VLOAD
• Minimum battery consumption
• Shutdown current ≤3μA
• Automatic mode transition
• Battery consumption ≤11μA in sleep mode (bypass operation, charge pump off)
• Battery consumption ≤38μA in sleep mode (bypass operation, charge pump on)
• Bias current IQ ≤13μA in sleep mode (skip mode)
• Robust 5V MOSFET driver
• Small solution size and low cost
• Maximum switching frequency: 2.2MHz
• Internal bootstrap diode
• Constant peak current limit across VIN range
• DCR inductor current sensing support
• QFN-20 package with wettable flanks
• AM band interference and crosstalk avoidance
• Optional clock synchronization
• Switching frequency range: 100kHz to 2.2MHz
• Selectable switching modes (FPWM, diode emulation, and skip mode)
• Reduced EMI
• Optional programmable spread spectrum
• Leadless package
• Programmability and flexibility
• Dynamic VOUT tracking
• Dynamic switching frequency programming
• Programmable line UVLO
• Adjustable soft-start
• Adaptive dead time
• PGOOD indicator
• Integrated protection features
• Cycle-by-cycle peak current limiting
• Overvoltage protection
• HB-SW short-circuit protection
• Thermal shutdown