Maxim dc/dc converters deliver up to 400mA output

The MAX1920/MAX1921 step-down dc/dc converters provide 400mA at outputs down to 1.25V and can switch at up to 1.2MHz. The devices fit in 6-pin SOT23 packages and are used to generate low-voltage core supplies.

The chips use a proprietary current-limited control scheme that operates at up to a 100 percent duty cycle to ensure LDO while maintaining a 505A quiescent supply current. An internal synchronous rectifier eliminates an external diode and provides 97 percent efficiency at 50mA and 87 percent efficiency at 1mA.

The MAX1920/21 have an input voltage range of 2V to 5.5V and output tolerance of 1.5 percent. The MAX1921 output is preset with internal resistors at voltages of 1.5, 1.8, 2.5, 3 and 3.3V. The MAX1920 output is adjustable from 1.25V to 5V using an external resistor-divider. Built-in soft-start limits startup currents.

The MAX1920/21 operate at the extended-industrial temperature range of -40°C to 85°C. Prices start at $1.35 for quantities of 2,500 and up.