High-voltage inrush/overcurrent input protection device

December 15, 2014 // By Graham Prophet
Analog Devices has posted details of the ADM1270, a current-limiting controller that provides inrush current limiting and overcurrent protection for modular or battery-powered systems.

The ADM1270 is designed to control the inrush current, when powering-on a system, via an external P-channel field effect transistor (FET); it manages the currents that charge bypass capacitors when circuit boards are inserted into a live backplane. These transient currents can cause permanent damage to connector pins, as well as dips on the backplane supply that can reset other boards in the system.

To protect a system from a reverse polarity input supply, there is a provision made to control an additional external P-channel FET. This feature prevents reverse current flow in case of a reverse polarity connection, which can damage the load or the ADM1270. The device comes in a 3 × 3 mm, 16-lead LFCSP and a 16-lead QSOP; use it in industrial modules, and in battery powered/portable instrumentation.

Features include;

  1. Controls supply voltages from 4 V to 60 V;
  2. Gate drive for low voltage drop reverse supply protection;
  3. Gate drive for P-channel FETs;
  4. Inrush current limiting control;
  5. Adjustable current limit;
  6. Foldback current limiting;
  7. Automatic retry or latch-off on current fault;
  8. Programmable current-limit timer for SOA;
  9. Power-good and Fault outputs;
  10. Analogue undervoltage (UV) and overvoltage (OV) protection.