Acquired Electronics360

Aerospace

Step-Down Supply Dissipates Low Power, Needs No Inductors

12 August 2016

The LTC3256 from Linear Technology Corporation is a highly integrated, high-voltage, low-noise, dual-output power supply, which takes a single positive input and generates 5 V and 3.3 V step-down supplies with high efficiency and no inductors.

LTC3256 step-down dual-output supply. Source: Linear Technology   LTC3256 step-down dual-output supply. Source: Linear Technology

The device features a 5.5 V to 38 V input voltage range and includes independently enabled dual outputs: a 5 V 100 mA supply, and a 250 mA 3.3 V low-dropout (LDO) regulator, for a total of 350 mA available output current. This combination of regulators offers much lower power dissipation than a dual-LDO solution. For example, at 12 V VIN and maximum load on both outputs, power dissipation is decreased by over 2 W with the LTC3256, thus reducing significant heat and input current.

The LTC3256 is engineered for diagnostic coverage in ISO26262 systems and incorporates numerous safety and system-monitoring features. The device is suited for applications requiring low noise, low power rails from a high-voltage input such as automotive ECU/CAN transceiver supplies, industrial and telecom housekeeping supplies, and general-purpose, low-power 12 V to 5 V and 3.3 V conversion.

The LTC3256 maximizes efficiency by running the charge pump in 2:1 mode, over as wide an operating range as possible, and automatically switches to 1:1 mode as needed, consistent with VIN and load conditions. Controlled input current and soft switching minimize conducted and radiated EMI. The device offers low quiescent current of only 20 μA with both outputs regulating (no load) and 0.5 μA in shutdown. The integrated watchdog timer, independent power-good outputs, and reset input ensure reliable system operation and enable fault monitoring. A buffered 1.1 V reference output enables system self-testing diagnostics for safety-critical applications.

The LTC3256 also has additional safety features, including over-current fault protection, over-temperature protection and tolerance of 38 V input transients.



Powered by CR4, the Engineering Community

Discussion – 0 comments

By posting a comment you confirm that you have read and accept our Posting Rules and Terms of Use.
Engineering Newsletter Signup
Get the Engineering360
Stay up to date on:
Features the top stories, latest news, charts, insights and more on the end-to-end electronics value chain.
Advertisement
Weekly Newsletter
Get news, research, and analysis
on the Electronics industry in your
inbox every week - for FREE
Sign up for our FREE eNewsletter
Advertisement

CALENDAR OF EVENTS

Date Event Location
23-27 Apr 2018 Oklahoma City, Oklahoma
10 May 2018 Pier 94
22-24 May 2018 Los Angeles, CA
04-07 Jun 2018 Boston, MA
06-08 Jun 2018 Los Angeles, CA
Find Free Electronics Datasheets
Advertisement