To reach 90 percent of the final value takes about 2.3 time constants. Cutoff clamping reduces the output voltage swing but makes the transition faster. Clamping the collector voltage to 63 percent of the final value allows a factor of two speed increase. The Baker clamp introduces a nonlinear negative feedback into a common-emitter stage (BJT switch), with the purpose to avoid saturation by decreasing the gain near the saturation point. While the transistor is in active mode and it is far away enough from the saturation point, the negative feedback is turned off and the gain is maximal; when the transistor approaches the saturation point, the negative feedback gradually turns on, and the gain quickly drops. To decrease the gain, the transistor acts as a shunt regulator with regard to its own base–emitter junction: it diverts a part of the base current to ground by connecting a voltage-stable element in parallel to the base–emitter junction. The two-diode Baker clamp circuit is shown in the figure from Baker's patent and in many other publications. The feedback diode (D1) between the collector and the input limits the collector voltage to approximately "V"BE by diverting the excessive input current through the collector to ground. An additional silicon diode is connected in series with the base terminal to raise the effective input voltage; the clamp diode in the collector–base feedback is sometimes made from germanium to minimize the voltage drop across it. The base diode allows a Si diode clamp to be used with a Si transistor and keeps "V"CE around a diode drop and much greater than "V"CE(sat). Unfortunately, it turns off and creates a high-impedance return path when trying to turn the transistor off. Although the base charge has been minimized, it is now more difficult to draw charge out of the base. A second base diode connected antiparallel to the base diode (D2 in Baker's schematic) will provide a low-impedance return path for removing stored base charge in the transistor. This three-diode circuit is still referred to as a Baker clamp by some sources, while others only call the two-diode circuit a Baker clamp. A simple alternative to the Baker clamp is a single low-voltage diode from the collector to the base. To work well, the forward drop of the diode must be less than the base–emitter drop, so low-voltage-drop germanium and Schottky diodes can be used with silicon transistors (the forward voltage drop of a Schottky diode is much less than the "V"BE bias voltage of a silicon transistor and it switches rapidly).