Search results
Results from the WOW.Com Content Network
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors.Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor"), as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logic (DTL).
Often two level shifters are used, one at each system: A line driver converts from internal logic levels to standard interface line levels; a line receiver converts from interface levels to internal voltage levels. For example, TTL levels are different from those of CMOS. Generally, a TTL output does not rise high enough to be reliably ...
TTL logic levels are different from those of CMOS – generally a TTL output does not rise high enough to be reliably recognized as a logic 1 by a CMOS input. This problem was solved by the invention of the 74HCT family of devices that uses CMOS technology but TTL input logic levels.
Higher speed than the original 74 series, at the expense of power dissipation. TTL logic levels. [24]: 6–2 [25]: 3–6 74L Low-Power 5 V ±5% 60 ns 3.6 mA −0.2 mA 1967 [26]: 72 Same technology as the original 74 family, but with larger resistors to lower power consumption at the expense of gate speed. TTL logic levels. Now obsolete.
The logic level on one wire is always the complement of the other. The principle is similar to that of low-voltage differential signaling (LVDS), but with different voltage levels. Differential TTL is used in preference to single-ended TTL for long-distance signaling. [4]
Some TTL logic parts were made with an extended military-specification temperature range. These parts are prefixed with 54 instead of 74 in the part number. [1]A short-lived 64 prefix on Texas Instruments parts indicated an industrial temperature range; this prefix had been dropped from the TI literature by 1973.
In digital electronics, a level shifter, also called level converter or logic level shifter, or voltage level translator, is a circuit used to translate signals from one logic level or voltage domain to another, allowing compatibility between integrated circuits with different voltage requirements, such as TTL and CMOS.
HCT stands for high-speed CMOS with transistor–transistor logic voltages. These devices are similar to the HCMOS types except they will operate at standard TTL power supply voltages and logic input levels. This allows for direct pin-to-pin compatible CMOS replacements to reduce power consumption without loss of speed.