Renesas Dual Sync Buck Controllers Perfectly Tailored for Automotive Always-On Applications

Renesas Electronics has just introduced two new 42V dual synchronous controllers, designed to deliver primary power for their R-Car H3 and M3 SoCs. These controllers feature a very low quiescent current of only 6µA and include built-in 2A source and 3A sink MOSFET drivers.

The first controller, ISL78264, is a dual synchronous buck controller that converts a 12V battery system down to 5V and 3.3V, making it suitable for powering the vehicle’s ECU, in-vehicle infotainment systems, and digital cockpits. It can handle power levels from 50W to 200W.

The second controller, ISL78263, is a dual synchronous boost and buck controller. It supports power levels from 25W to 100W and offers a pre-boost feature that helps maintain a stable voltage even if the battery’s voltage drops to as low as 2.1V during events like engine cranking or start-stop scenarios.

According to Niall Lyne, vice president at Renesas, these controllers are perfect for managing the primary power regulation in Renesas’ automotive SoCs. They bring new electronic architectures to the table that enhance vehicle performance, efficiency, safety, and reliability. Their low quiescent current is a standout feature, allowing power system designers to meet strict power budgets of down to 50µA or 100µA.

Both controllers make power supply design easier by integrating FET drivers that offer 96% peak efficiency and can manage output currents exceeding 10A. They come with built-in feedback resistors, supply blocking diodes for cranking support, and programmable spread spectrum to mitigate EMI interference.

Tolerating VBAT load dumps lowers surge protection costs and space, while supporting cranking transients reduces the need for large input capacitance. They also feature built-in EMI mitigation with switching frequencies up to 2.2MHz, which further cuts down the cost and size of EMI filtering and shielding.

The controllers are protected against overvoltage, undervoltage, overcurrent, and overtemperature conditions. They also feature a bootstrap supply undervoltage detection and refresh circuit to safeguard the high-side MOSFET. Additionally, both controllers meet the AEC-Q100 grade-one qualification for ambient operations ranging from -40 to +125 degrees Celsius.

Key features of the ISL78264 include:
– Input voltage range from 3.75V to 42V
– Fixed output voltages of 3.3V and 5V, adjustable from 0.8V to 5V
– Adjustable second buck output from 0.8V to 32V
– Typical 6µA quiescent current over a single buck channel
– 25ns on-times for low duty-cycle operation and 180-degree phase shift between channels
– No need for pre-boost during start-stop cranking down to 5.5V at 2MHz

Key features of the ISL78263 include:
– Input voltage range from 2.1V to 42V
– Fixed buck outputs of 3.3V and 5V, adjustable
– Maintains regulation through cold-crank transients down to 2.1V
– Boost frequency at either 1x or 0.2x the buck frequency
– Drop-out mode for high duty-cycle operations
– 25ns on-times for low duty-cycle operation

These controllers are available in mass production quantities in compact 5x5mm, 32-lead QFN packages.