Two-Phase, Dual DC-DC Converter Gives Batteries Legs

The LTC1628 is claimed as the world’s first two-phase, current-mode switching regulator. Unlike traditional single-phase dual switching regulators, the device interleaves the current pulses coming from the switches by operating its switch drivers 180° out of phase. This minimizes the overlap time when the current pulses add together, thus reducing RMS input current. As a result, the two-phase technique decreases input capacitance ESR requirements by 50% compared with single-phase regulators, reduces radiated and conducted EMI, and improves efficiency. The device also provides OPTI-LOOP compensation, which enables optimization of transient response with minimal output capacitance. These and other features are said to enable the LTC1628 to shrink design size and extend battery life in portable systems.Output regulation is 0.2% over line and load variations. Protection circuits include foldback current limiting.