Linear – Latest micro regulator protects inputs and supports asymmetric power sharing (LTM8026)Mar 19 2012 - Power [More Power Articles]
The LTM8026 is a new 36V input, 5A step-down µModule regulator from Linear Technology, offering an adjustable and precise (+/-10%) accurate current limit. The current limit enables designers to set the maximum amount of power drawn from the supply, preventing input voltage droop caused by over-current conditions.
When multiple LTM8026 are configured with the outputs tied together, each converter can be programmed with a ‘unique’ maximum current limit to meet its specific input supply limitations for greater output power, a technique known as asymmetric power sharing. In contrast, common regulators must current share, a feature where each input supply contributes equally to the load, which is restricted by the least powerful input rail. Applications for the LTM8026 include point of load regulation in systems with 24V and 12V supplies such as VXI bus, for automotive, medical and industrial end-markets.
Like other Linear Technology µModule regulators, the LTM8026 includes the DC-DC controller, power switches, power inductor, compensation and a modest amount of input and output capacitance in a surface mount package. The current limit is adjustable by applying a voltage or resistor divider and can be automatically decreased with rising junction or ambient temperature using a thermistor to prevent the LTM8026 or load from overheating.
The LTM8026 operates from an input voltage between 6V to 36V and regulates an output voltage between 1.2V to 24V set by a single resistor. In a 12V to 3.3V output application, the LTM8026 achieves an operating efficiency of 89% at 2A. For noise-sensitive applications, the µModule regulator can be synchronized to an external clock frequency in the range of 100kHz to 1MHz. Additional features include externally adjustable soft start, adjustable switching frequency and thermal shutdown.
The LTM8026 is packaged in a thermally efficient 11.25mm x 15mm x 2.82mm LGA package. Two temperature grades, E and I for the -40C to +125C temperature range, are available, says the company.More news from Linear