New Industry Products

Panasonic Develops LSI Series DC-DC Converters with a Voltage Step-down Type Hysteretic Control System

December 18, 2011 by Jeff Shepard

The Semiconductor Company of Panasonic Corp. has developed the LSI series dc-dc converters with a voltage step-down type hysteretic control system (part numbers: NN3019 and NN3031 series) to provide high-efficiency and high-speed response. These Panasonic converter LSIs can support a wide-range of output voltages, and they are ideal for the power supplies of personal computers and servers. Panasonic will begin shipping samples in January 2012 (sample unit price: 100 to 200 yen).

The conventional control systems, such as those using voltage mode or current mode, were unable to respond to rapid changes in the output load at high speed. Furthermore, in conventional monolithic ICs, large switching devices were required to cope with a large current output, making it very difficult to miniaturize dc-dc converters. In order to resolve these issues, there has been demand for dc-dc converter LSIs that can achieve high-efficiency, high-speed response for miniaturized power supply circuits.

The new Panasonic LSI series will improve the efficiency of power supplies capable of handling large current capacity (up to 10A) for personal computers and servers. The series will also help to achieve greater energy conservation in the equipment’s operation. The high-performance power supplies in a small package will also permit equipment to be further miniaturized.

Panasonic’s high-efficiency and high-speed LSIs offer important advantages:

1. Thanks to the built-in field effect transistors with a low-loss trench-gate metal-oxide semiconductor (MOS) structure, the power conversion efficiency has reached 95%. This will contribute to the equipment’s energy conservation and low heat generation.

2. The LSIs can respond to rapid changes in the output load at high speed and significantly suppress variations in the output voltage. Undershoot: 9mV Overshoot: 11mV

These characteristics ensure a large margin in the operating voltage range of the Field Programmable Gate Arrays (FPGA), memories, digital signal processors (DSP), and other components installed in personal computers and servers.

3. The number of components to be mounted on a power supply board can be reduced. The adoption of small packages (4 mm/6 mm square) can reduce the mounting dimension by approximately 25%.

These products have been achieved through key technologies:

1. Trench-gate metal-oxide semiconductor field-effect transistors (MOSFET) control-circuit technologies balance high-speed switching and low loss.

2. Technologies for controlling specified pulse width modulation (PWM) ON/OFF time can speed up the hysteretic control system’s operation and respond to rapid changes in the output load at high speed.

3. Multi-chip mounting technologies for trench-gate MOSFET and controller ICs for mounting onto small quad flat non-leaded (QFN) packages help to reduce the number of mounted components.