Leadis Technology Expands Flexible LDO Controller Family To Drive NMOS & NPN Pass Transistors

Leadis Technology, Inc. announced sample availability of the LDS124P and LDS128P, a new family of Low Drop Out linear regulator (LDO) controllers that are designed to drive NMOS or NPN pass transistors.

The LDS124P and LDS128P complement an existing LDO controller, the LDS120P, and are targeted for applications including graphic cards, PC motherboards, switching power supply post-regulation, telecom equipment, and consumer applications such as LCD-TV. The LDS124P and LDS128P are designed to drive NMOS or NPN pass transistors to regulate output voltages from 1.24 to 12V. The LDS124P is a single-channel LDO controller, the LDS128 is a dual-channel LDO controller.

"Leadis is committed to increasing energy efficiency in all the applications we serve," said Paul Greenland, Senior Director of Power Management at Leadis Technology. "As IC loads become complex and sophisticated the number of power rails in a system or on a card increases. Load current scalable solutions reduce inventory costs, eliminating circuit blocks that are redundant in the power chain, increasing power density and reliability. We believe these adaptable point of load regulation solutions will become an industry standard in a diverse range of multi-rail applications."

The LDS124 is a single-channel LDO controller designed to drive an NMOS or NPN pass transistor to regulate output voltages from 1.24 to 12V. At the heart of the LDS124 is a precision temperature compensated 1.24V reference. Its drive pin is capable of 100mA of sink current controlling up to 10A through a pass transistor. An NMOS pass transistor is preferred for load currents greater than 2.5A. This combination, available in SOT-23 or TO-92 packages makes a very flexible regulator in terms of VOUT and IOUT, which can be implemented where space is at a premium.

The LDS128 is a dual-channel LDO controller in a SOT-23-5 package. Designed to drive NMOS or NPN pass transistors, the LDS128 has two independent precision temperature compensated LDO controllers for setting two output voltages from 1.24 to 12V. Each drive pin is capable of sinking 20mA, controlling two separate pass transistors. Ultra-low dropout operation is possible by taking the drive pin bias supply to a higher voltage than VIN, to the 12 V rail in a PCI-Express card for instance. This combination makes two versatile voltage regulators in terms of VOUT and IOUT for applications with many auxiliary power rails.

The LDS120 is a versatile LDO controller. The LDS120 permits the setting of VOUT at load currents up to 2A with the minimum number of external components.

The open collector output is capable of driving an external PNP or PMOS pass transistor. A temperature compensated bandgap reference (1.25V) controls the output voltage, which is programmable through an external potential divider.