Torex Introduces Dual Output Step-Up/Inverting DC-DC Converter Series

Torex Semiconductor Ltd. has developed a dual output step-up/inverting dc-dc converter, called the XC9519 series.

The XC9519 series is 2-ch step-up/inverting dc-dc converter. Using external components, the step-up dc-dc converter can be set to any desired voltage up to 18V, and the inverting dc-dc converter can be set to any desired voltage down to -15V. The switching frequency is a high 1.2MHz, enabling the use of small external components.

The input voltage range is 2.7 to 5.5V. The output current is 500mA (VIN=3.7V, VOUTP=5.0V, VOUTN=-5.0V). PWM control and automatic PWM/PFM switching control can be selected for the operation modes. The switching frequency of PWM control is fixed, thereby reducing noise. Automatic PWM/PFM switching control switches from PWM control to PFM control when the load is light to achieve high efficiency across the entire load range, from light loads to high output currents.

The step-up dc-dc converter has a built-in soft start time of 2.5ms (TYP.), while the inverting dc-dc converter’s soft start time is 2.2ms (TYP.). The supply current is 1.0µA or less in standby. A gate control circuit for an external P-ch MOSFET for load cut-off is incorporated. By adding an external P-ch MOS FET, the load can easily be cut-off in standby. Protective circuits include driver Tr current limiting (2A MIN.) and thermal shutdown. A UVLO function that forces the driver Tr. off at an input voltage of 2.2V or less is also incorporated. The IC is housed in a small QFN-24 (4.0 x 4.0 x h0.8 mm) package.