| 327 / | HD | MISCELLANEOUS ACTIVE ELECTRICAL NONLINEAR DEVICES, CIRCUITS, AND SYSTEMS |
| 100 | DF | SIGNAL CONVERTING, SHAPING, OR GENERATING {29} |
| 185 | DF | .~ Particular stable state circuit (e.g., tristable, etc.) {12} |
| 199 | DF | .~.~ Circuit having only two stable states (i.e., bistable) {11} |
| 224 | | .~.~.~ With single semiconductor device |