International Rectifier introduced the IR3823 SupIRBuck integrated voltage regulator designed for space-constrained, energy efficient netcom, server and storage applications.The IC delivers up to 3A a 3.5×3.5mm package. Efficiencies in excess of 97.5% are obtainable for designs converting power from a 6V input to a 4.8V output.
The extremely high initial efficiency allows switching at up to 1.5MHz from a 12V supply to enable a complete 3A power supply solution in less than 130mm2. Featuring constant frequency and virtually jitter-free operation with synchronization capability, the new device is well suited to noise-sensitive applications, while the higher bandwidth reduces component count to shrink PCB footprint. A tri-level selectable soft-start feature is also offered for ease of sequencing.
The regulator features programmable switching frequency from 300kHz to 1.5MHz. Other key functions include thermally compensated over-current protection, output over-voltage protection and thermal shutdown.
Voltage loop compensator design
Since the regulator uses a voltage mode control, an input voltage feedforward architecture, the feedback loop design is independent of the input voltage. An RC network needs to be connected between the FB pin and the COMP pin to form a feedback compensator. This allows a high control bandwidth with a phase margin of 45o or more. This allows the design to use fewer of output capacitors as well as ensuring solid stability in the circuit.
For more detail: IR’s integrated voltage regulator with 97.5% efficiency