New Industry Products

Ultra-Low-Power Step-Up DC-DC Converter with Integrated Coil

March 05, 2014 by Jeff Shepard

Torex Semiconductor, Ltd. has introduced the XCL101 series, the first step-up type converter in the XCL series of micro dc-dc converters with an integrated coil. The XCL101 dc-dc converters are in an ultra-small CL-2025 package (dimensions: 2.5mm x 2.0mm x h1.0mm). A stable and efficient 330mW power supply circuit can be configured by simply adding only two ceramic capacitors externally thereby contributing to PCB space saving and the shortening of development time. Integration of the coil simplifies the board layout and minimizes any unwanted radiated noise.

With an operating voltage range of 0.9V to 5.5V, this series is ideal for applications that run on a single alkaline or nickel-hydrogen battery. An output voltage of 1.8V to 5.0V can be selected in steps of 0.1V (±2.0% accuracy). The device is rated for an output current of 100 mA. Synchronous rectification PFM control is used for the control method which minimizes the quiescent current to only 6.3μA as well as achieving high efficiency. The XCL101 series has an internal inrush current prevention circuit to reduce any potential device instability that can be caused by inrush current when the IC starts.

The XCL101 series also features a soft-start circuit and an enable pin to turn the IC on and off and a load disconnect function that prevents the battery charge from leaking to the output while the IC is not operating (XCL101A). An optional CL discharge function can quickly discharge the output capacitor when the IC is turned off and an Input by-pass mode function type is also available to keep the connection between the input and output side during shutdown (XCL101C).

Current limit PFM control is used for the control method to make it difficult for the output voltage ripple to increase even when the switching current is superimposed, so the product can be used within a wide voltage and current range. Further, because PFM control is used, it has excellent transient response to support low capacity ceramic capacitors to realize a compact, high-performance boost DC/DC converter. The synchronous driver and rectifier switch Tr efficiently sends the coil energy to the capacitor connected to the VOUT pin to achieve highly efficient operation from low to high loads.

The XCL series has an operating temperature range of -40 to +85 degrees C and is an environmentally-friendly product that complies with the EU RoHS Directive and is Pb, halogen and antimony free. In the future, Torex will continue to strengthen its lineup of XCL series coil-integrated “micro dc-dc” converters to meet market needs.