STs PWM controllers now include the standard current-mode (UC family) and voltage mode (SG family). Both product families are highly flexible because it can support isolated and non-isolated AC-DC and DC-DC power supplies with the use of the most advanced and reliable topologies, both single-ended and double-ended. Generally, the current-mode is ideally used for applications with substansial load transient requirements because of its faster vigorous response and lower audio susceptibility. In comparison, the voltage mode provides a more basic solution when the duty cycle exceeds 50% or when the noise sensitivity is crucial. ST's controllers are considered as the top of the line compared to the others. ST controllers are widely known for its world class quality and high efficiency.