The LM61440-Q1 is a wide input, synchronous peak-current mode buck regulator designed for a wide variety of automotive applications. The regulator can operate over a wide range of switching frequencies including sub-AM band at 400 kHz and above the AM band at 2.1 MHz. This device operates over a wide range of conversion ratios. If minimum on-time or minimum off-time does not support the desired conversion ratio, the frequency is reduced automatically, allowing output voltage regulation to be maintained during input voltage transients with a high operating-frequency setting.

The LM61440-Q1 has been designed for low EMI and is optimized for both above and below AM band operation:

• Meets CISPR25 class 5 standard
• Hotrod™ package minimizes switch node ringing
• Parallel input path minimizes parasitic inductance
• Spread spectrum reduces peak emissions
• Adjustable SW node rise time

These features together can eliminate shielding and other expensive EMI mitigation measures.

This device is designed to minimize end-product cost and size while operating in demanding automotive environments. The LM61440-Q1 can be set to operate in the range of 200 kHz through 2.2 MHz using its RT pin. Operation at 2.1 MHz allows for the use of small passive components. State-of-the-art current limit function allows the use of the inductors that are optimized for 4-A regulators. In addition, this device has low unloaded current consumption, which is desirable for off-battery, always on applications. The low shutdown current and high maximum operating voltage also allow for the elimination of an external load switch and input transient protection. To further reduce system cost, an advanced PGOOD output is provided, which can often eliminate the use of an external reset or supervisory device.

The LM61440-Q1 devices are AEC-Q100-qualified and have electrical characteristics ensured up to a maximum junction temperature of 150°C.