Products - Step-Down

XCL219 World's Smallest 1A Buck Micro DC/DC

World's Smallest 1A Buck Micro DC/DC image


Property XCL219
Output Current 1.0A
Input Voltage 2.5 ~ 5.5V
Output Voltage 0.8 ~ 3.6V
Oscillation Frequency 3MHz
Quiescent Current 400µA
Packages CL-2025-02

Product Description

World's Smallest 1A Buck Micro DC/DC

Application Notes

This Step-Down micro DC/DC Converters measure only 2.5mm x 2.0mm x 1.0mm and are designed to minimize EMI emissions and maximize efficiency, while delivering a very stable output with low peak to peak ripple Voltage (<10mV).

Utilising HiSAT-COT, Torex’s Constant ON Time architecture, the XCL219 provides extremely fast load transient response performance in comparison to standard DC/DC solutions. HiSAT-COT also provides less fluctuation in oscillation frequency against load and input voltage when compared to traditional COT control architectures.

Operating from input voltages as low as 2.5V up to 5.5V and consuming only 25μA when operating with no load, the XCL219 is a perfect fit for applications where PCB space is at a premium. Internally, the XCL utilizes a simple package construction with low production costs resulting in a truly cost effective solution for high volume consumer applications.

The XCL219 has been designed to minimize this unwanted noise, making it ideal for sensitive RF applications. When tested and compared with a conventional DC/DC circuit with an external coil, the XCL219, with its integrated coil, shows a significant reduction in radiated noise achieved across all frequency bands.

The small size and simple circuit architecture makes the XCL219 an ideal replacement for inefficient LDO voltage regulators and by integrating the coil, it has simplified the circuit layout for the designer and reduced the number of external components normally needed to implement this type of DC/DC solution.

The smaller circuit layout also means less PCB tracking, which helps further reduce the radiated noise. The XCL219 operates with fixed frequency PWM control  providing fast response, low ripple and high efficiency over the full range of load conditions (from light load to heavy load).

The XCL219 series include a 0.25ms (typ.) high speed soft-start function for quick turn-on, a chip enable pin to turn the IC on and off and an optional CL discharge function to quickly discharge the output capacitor when the IC is turned off. A thermal shutdown circuit is also built in which shuts down the IC when the chip’s temperature reaches 150°C and re-starts it when the temperature drops to 120°C (TYP.) or less.

Other features include a built-in UVLO (Under Voltage Lock Out) circuit whose threshold is 1.6V (typ). The XCL219 will stop operating when the input voltage decreases below this threshold, and will resume normal operation when the input voltage rises above this threshold.

XCL219 Typical Application Circuit

XCL219 Oscillation Frequency vs Output