Power
UltraFast - Digitally Programmable 5A LDO Features 85mV Dropout & 25uVRMS Noise
Linear Technology has announced the LT3070, a digitally programmable linear regulator with the lowest dropout voltage, lowest noise and fastest transient response of any monolithic 5A LDO currently available. Dropout voltage at 5A is an ultralow 85mV. Output voltage noise at 5A is only 25uVRMS over a 10Hz to 100kHz bandwidth. The LT3070's 1MHz unity gain bandwidth, coupled with its minimum 15uF ceramic output capacitance, provides a mere 30mV of overshoot/undershoot in response to a fast 4.5A output load step, saving significant bulk capacitance, space and cost.
The Multiple LT3070 devices can be easily paralleled for higher output current and to spread heat across a PCB. A tracking feature can control a buck regulator powering the LT3070's input. This tracking function drives the upstream buck regulator to maintain the LT3070's input voltage at VOUT + 300mV, minimizing power dissipation. If output voltage is dynamically changed, the tracking function automatically adjusts the output voltage of the buck regulator to maintain efficiency. Internal protection circuitry includes UVLO, reverse-current protection, precision current limiting with power foldback and thermal shutdown with hysteresis.