Southchip has introduced industrial-grade high-voltage ultra-low quiescent current buck converter series. With a remarkably low quiescent current of only 10μA, the series supports a maximum voltage withstand of 120V and a continuous current of up to 5A. The high voltage tolerance significantly reduces the need for external voltage spike suppression components, lowering both solution size and cost. The ultra-low quiescent power consumption greatly extends the standby time of battery-powered devices. This product series offers a stable and high-performance alternative for applications such as robotics, communication power supplies, E-bikes, power tools, energy storage, and BMS.

The series adopts SOP8/ESOP8 packaging, with pin compatibility mainstream international manufacturers’ products. No PCB redesign is required—direct pin-to-pin (P2P) replacement ensures compatibility with existing solutions, facilitating localized alternatives and effectively reducing R&D costs.

In high-voltage scenarios, even relatively low quiescent currents can lead to significant power losses. For battery-powered devices, low power consumption substantially reduces self-discharge losses and extends battery life. The new series employs a low-power design, reducing the IC’s quiescent current to 10μA, effectively minimizing standby losses during light-load conditions and improving light-load efficiency. Additionally, the SC81XXE series provides an EXT pin for IC power supply. Connecting the EXT pin to the output or an external 5–12V power source further enhances light-load energy efficiency.

 

Standby current comparison

Low power conversion efficiency not only wastes energy and shortens battery runtime but also generates high temperatures that challenge the reliability and lifespan of electronic products. Southchip’s series features built-in MOSFETs with significantly lower on-resistance than industry counterparts, improving heavy-load efficiency and reducing system temperature rise.

Efficiency comparison: VIN=72V,VO=12V

 

SC81A30’s MOSFET on-resistance is only 40% of competing products, with a measured temperature rise 15.2°C lower under the same conditions. (Test conditions: TA=27°C, VIN=72V, VO=12V, IO=3.5A, 300kHz.)

The series adopts a Constant On-Time (COT) control topology. An external RCC ripple injection circuit ensures stable DCDC operation across a wide range of applications while delivering optimal transient response. No external VCC capacitor is needed, simplifying PCB layout and aligning with the trend of miniaturization and high performance in industrial equipment. Compared to traditional peak current control modes, this design enables faster transient response.

VIN=48V, VO=12V, IO=1.5A to 3A in 1μs, with consistent peripheral parameters.

 

To ensure the safety and reliability of industrial systems, the series provides full protection features, including input undervoltage protection, cycle-by-cycle peak current limiting, short-circuit protection with auto-frequency reduction and hiccup mode, and overtemperature shutdown protection.

The series offers a wide range of product options, allowing users to select the most suitable voltage and current specifications for their applications, optimizing cost-effectiveness.

Southchip has established a comprehensive DC-DC product family covering general-purpose DC-DC, charge pump DC-DC, and load switches. The 120V voltage withstand capability of this series supports a broad range of industrial applications, while achieving low quiescent current and sustained high load currents, further expanding the usage scenarios of Southchip’s power management ICs. Currently, the product is undergoing sample testing at multiple client sites.