The SC1548 is identical to the SC1538, except it provides only a single linear FET controller. Since the FETs being controlled are not switching, they need not be located close to the SC1538 or SC1548 devices, enabling them to be placed in any convenient location which simplifies printed circuit board layout. The new devices provide separate Enable inputs for each linear FET controller, and offer over current protection via feedback through external Sense inputs. Under typical conditions, if any output drops below one volt for more than four milliseconds, the output is shut down. This over current feature is blanked for approximately 5ms at startup to avoid false triggering due to output capacitor inrush currents.
Devices are available in production quantities immediately.
Key applications such as computer systems, telecommunications systems and DSP-based systems require power supplies with superior voltage regulation capabilities over wide load, line, and temperature variations. Other features such as over current protection, low power dissipation, and undervoltage lockout are desirable in many applications. Semtech has introduced a couple of linear FET controllers that offer those features and many more. The SC1538 and SC1548, along with external FETs, offer well regulated output voltages with over current protection. Comprehensive design support is offered by Semtech in an effort to make the life of many engineers and designers easier.