A relatively fast bipolar logic family, normally produced in integrated-circuit form, whose internal configuration is similar to normal TTL except that Schottky transistors are used. These transistors can be considered as equivalent to a normal bipolar transistor with a Schottky diode connected across the base-collector junction. The Schottky diode is a semiconductor-metal diode that has a low cut-in voltage (forward bias voltage drop), typically 300 millivolts, compared with 600 mV for other common semiconductor diodes. It also has a relatively high switching speed. In Schottky TTL the low cut-in voltage of the diode limits the base-collector voltage to about 400 mV, which prevents the transistor falling into saturation. This results in faster switching times for the transistors constructed in this way.