Tiny µModule boost regulator for low voltage optical systems

Analog Devices has launched the Power by Linear LTM4661, a low power step-up µModule regulator in a 6.25mm x 6.25mm x 2.42mm BGA package. Only a few capacitors and one resistor are required to complete the design, and the solution occupies less than 1cm² single-sided or 0.5cm² on double-sided PCBs.

The LTM4661 incorporates a switching DC/DC controller, MOSFETs, inductors and supporting components. It operates from a 1.8V to 5.5V input supply, and continues to operate down to 0.7V after start-up. The output voltage can be set by a single resistor ranging from 2.5V to 15V.

The device is designed for optical modules, battery-powered equipment, battery-based backup systems, bias voltage for power amps or laser diodes and small DC motors.

The LTM4661 can deliver 4A continuously under 3.3VINto 5VOUT, and 0.7A continuously under 3.3VINto 12VOUT. It also employs synchronous rectification, which Analog says delivers as high as 92% conversion efficiency (3.3VINto 5VOUT).

The switching frequency is 1MHz, and can also be synchronised to an external clock ranging from 500kHz to 1.5MHz. Analog adds that its 1MHz switching frequency and dual phase single output architecture enable fast transient response to line and load changes and a significant reduction of output ripple voltage. The device operates from –40℃to 125℃operating temperature.

There are three operation modes: Burst Mode operation, forced continuous mode and external sync mode. The quiescent current in Burst Mode operation is only 25µA, which provides extended battery run time. For applications demanding the lowest possible noise operation, the forced continuous mode or external sync mode minimize possible interference of switching noise.

The LTM4661 features an output disconnect during shutdown and inrush current limit at start-up. Fault protection features include short-circuit, overvoltage and overtemperature protection.

Author
Bethan Grylls