New Industry Products

Compact 600mA Synchronous Step-Down DC-DC with P-Ch High-Side Switch

July 15, 2019 by Scott McMahan

The XC9267/68 from Torex Semiconductor is a synchronous step-down dc-dc with P-channel high-side switch to ensure low voltage operation with 100% max duty ratio.

It can operate from 3.0V to 36.0V and deliver loads up to 600mA making it a suitable replacement for inefficient linear regulators used in many industrial applications. Typical applications include electric meters, gas detectors, various sensors, industrial equipment, and home appliances. (See typical application diagram above).

Available in the ultra-small USP-6C package, measuring 2.0mm x 1.8mm x 0.6mm, the dc-dc circuit needs only a minimal number of external components.

Torex designed the dc-dc converter for very high efficiencies at low output loads. It features low quiescent current and automatic PFM/PWM mode. The XC9267/68 also works with low ESR ceramic capacitors and comes with a choice of two switching frequencies, adjustable soft-start, and a power-good output.

A 0.75V reference voltage source is incorporated, and the output voltage can be set to a value from 1.0V to 25.0V using external resistors. A switching frequency of 1.2MHz or 2.2MHz can be selected. The soft-start time is internally set to 2.0ms (typ.), but it can be adjusted to a longer time using an external resistor and capacitor. With the built-in UVLO function, the driver transistor is forced OFF when the input voltage becomes 2.7V or lower.

An included fold-back type current limit circuit enables the device to automatically resume regular operation as soon as the over-current condition disappears.


  • Input Voltage Range: 3.0V to 36V (Absolute Max 40V)
  • Output Voltage Range: 1.0V to 25V
  • FB Voltage: 0.75V±1.5%
  • Oscillation Frequency: 1.2MHz, 2.2MHz
  • Output Current: 600mA
  • Control Methods: PWM control
    • Efficiency: 88%@12V→5V, 300mA
    • Soft-start Time: Adjustable by RC
  • Protection Circuits:
    • Over-Current Protection: Thermal Shutdown
    • Output Capacitor: Ceramic Capacitor
  • Operating Ambient Temperature: - 40℃ to + 105℃
  • Packages:
    • SOT-89-5 (Without Power Good)
    • USP-6C (With Power Good)
  • Environmentally Friendly EU RoHS Compliant, Pb Free

Samples and evaluation boards are now available.