The LM5123-Q1 device is a wide input range synchronous boost controller that employs peak current mode control. The device features a low shutdown I_Q and a low I_Q sleep mode, which minimizes battery drain at no/light load condition. The device also supports an ultra-low I_Q deep sleep mode with bypass operation, which eliminates the need for an external bypass switch when the supply voltage is greater than the boost output regulation target. The output voltage can be dynamically programmed by using the tracking function.

The wide input range of the device supports automotive cold-crank and load dump. The minimum input voltage can be as low as 0.8 V when BIAS is equal to or greater than 3.8 V. The switching frequency is dynamically programmed with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response. Controller architecture simplifies thermal management at harsh ambient temperature conditions when compared to converter architectures.

The device has built-in protection features such as peak current limit, which is constant over VIN, overvoltage protection, and thermal shutdown. External clock synchronization, programmable spread spectrum modulation, and a lead-less package with minimal parasitic, help reduce EMI and avoid cross talk. Additional features include the following:

• Line UVLO
• FPWM
• Diode emulation
• DCR inductor current sensing
• Programmable soft start
• Power-good indicator