Synchronous DC/DC Converter for two-wire Sensor Systems
Sensors which are supplied via a two-wire connection in most cases only require a very low current, and in most cases have two main requirements: They often need high input voltages (due to the bus systems used, and due to crosstalk on the supply line), and high efficiency (due to the limited input power).
It was for these applications in particular that MPS developed the MPQ4568 step-down converter. It operates at input voltages of between 4.5 and 45V, which means it can even tolerate transients of 60V. Maximum output current is 100mA.
A shutdown mode, with very low current consumption (5µA), allows for this module to be used with battery-driven applications.
An adjustable current limitation allows for optimization of the circuit with regard to efficiency or output ripple voltage.
But the really special feature is the behavior under light load. For example, with converting from 10V to 3.3V at 10mA, 91.2% efficiency can still be achieved, and at 3mA it s still 90.1%. This puts the MPQ4568 more than 2% ahead of the competition in these ranges.
In order to achieve problem-free operation with high-Ohmic sources, the MPQ4568 has an adjustable start time (soft-start), as well as an adjustable start threshold with adjustable hysteresis.
The MPQ4568 comes in a small 3x3mm QFN package, and is immediately available.