Operating from an input voltage ranging from 2.375 to 20V, the part regulates two output voltages adjustable from 0.6 to 5.5V. Each output is a synchronous buck converter operating at high efficiency. When delivering full current at a 1.8V load from input supplies of 12V, 5V and 3.3V, the device is said to have an efficienciy of 88%, 91% and 93%, respectively.
The two 4A outputs can be current shared as one 8A output, with precision voltage regulation of ±1.5% over line and load variations guaranteed from -40 to 125°C.
The LTM4642 can be synchronised to a supplied clock with a frequency ranging from 600kHz to 1.4MHz. Output ripple voltage is reduced because of the device’s 180° out-of-phase operation. Low package thermal impedance enables full load current up to 95°C ambient temperature with no airflow, or 100°C with 200ft/min cooling, when converting a 12V input into a 1V output.
