Circuit Isolation Technique for Module-In-Place Testing
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
Integrated circuit (I/C) modules are electrically isolated while "in- circuit" on a printed circuit (PC) board. A common technique of PC board testing is Module-In-Place-Testing (MIPT). This requires the ability to electrically isolate every I/C module (or region) on the PC board. Several methods are available to do this, e.g., tri-stating, degating, power plan isolation, etc. However, many commonly available I/C modules do not provide this capability. It still is possible to test some of these devices "in circuit" through overdrive techniques (also known as backdriving). Another method is to insert extra circuitry on the PC board to provide the isolation capability (for increased testability of the PC board).