Transparent power management mode, integrated MMU and TTL compatible inputs ( only 386SXSA ).

The designation TTL is sometimes used to mean TTL-compatible logic levels, even when not associated directly with TTL integrated circuits, for example as a label on the inputs and outputs of electronic instruments.

TTL inputs are the emitters of a multiple-emitter transistor.

Like DTL, TTL is a current-sinking logic since a current must be drawn from inputs to bring them to a logic 0 level.

TTL is particularly well suited to bipolar integrated circuits because additional inputs to a gate merely required additional emitters on a shared base region of the input transistor.

* Schottky TTL ( S ), introduced in 1969, which used Schottky diode clamps at gate inputs to prevent charge storage and improve switching time.

Although all semiconductors can be damaged by electrostatic discharge, the high impedance of CMOS inputs makes them more susceptible than bipolar transistor-based, TTL, devices.

In contrast to TTL, CMOS uses almost no power in the static state ( that is, when inputs are not changing ).

One major improvement was to combine CMOS inputs and TTL drivers to form of a new type of logic devices called BiCMOS logic, of which the LVT and ALVT logic families are the most important.

TTL logic inputs that are left un-connected inherently float high, thus they require a much lower valued pull-down resistor to force the input low.

The tracert ( traceroute ), Pathping commands are implemented by transmitting UDP datagrams with specially set IP TTL header fields, and looking for ICMP Time to live exceeded in transit ( above ) and " Destination unreachable " messages generated in response.

* The TTL field of IPv4 has been renamed to Hop Limit, reflecting the fact that routers are no longer expected to compute the time a packet has spent in a queue.

They are activated by AC control signals or DC control signals from Programmable logic controller ( PLCs ), PCs, Transistor-transistor logic ( TTL ) sources, or other microprocessor and microcontroller controls.

Nameservers may also have a TTL set for NXDOMAIN ( acknowledgment that a domain does not exist ); but they are generally short in duration ( three hours at most ).

Newer DNS methods that are part of a DR ( Disaster Recovery ) system may have some records deliberately set extremely low on TTL.

For example a 300 second TTL would help key records expire in 5 minutes to help ensure these records are flushed world wide quickly.

TTL values are " per record " and setting this value on specific records is normally honored automatically by all standard DNS systems world-wide.

Mutable ( and therefore unauthenticated ) IPv4 header fields are DSCP / TOS, ECN, Flags, Fragment Offset, TTL and Header Checksum.

TTL chips are now are also made in surface-mount packages.

Successors to the original bipolar TTL logic often are interchangeable in function with the original circuits, but with improved speed or lower power dissipation.

TTL outputs are typically restricted to narrower limits of between 0 V and 0. 4 V for a " low " and between 2. 6 V and 5 V for a " high ", providing 0. 4V of noise immunity.

Designers can combine ECL and TTL devices in the same system to achieve best overall performance and economy, but level-shifting devices are required between the two logic families.

The TTL " totem-pole " output structure often has a momentary overlap when both the upper and lower transistors are conducting, resulting in a substantial pulse of current drawn from the power supply.

V < sub > CC </ sub > and Ground are carryovers from TTL logic and that nomenclature has been retained with the introduction of the 54C / 74C line of CMOS.

The increased low output level can cause troubles when TTL logic circuits are driven.

Schottky metal – semiconductor junctions are featured in the successors to the 7400 TTL family of logic devices, the 74S, 74LS and 74ALS series, where they are employed as clamps in parallel with the collector-base junctions of the bipolar transistors to prevent their saturation, thereby greatly reducing their turn-off delays.

Going on these figures alone TTL logic gates are limited to perhaps 2 to 10, depending on the type of gate, while CMOS gates have DC fan-outs that are generally far higher than is likely to occur in practical circuits ( e. g. using NXP Semiconductor specifications for their HEF4000 series CMOS chips at 25 ° C and 15 V gives a fan-out of 34 thousand ).

The 7400 series of transistor-transistor logic ( TTL ) integrated circuits are historically important as the first widespread family of TTL integrated circuit logic.

An integrated circuit made in CMOS is not a TTL chip since it uses field-effect transistors ( FETs ) and not bipolar junction transistors, but similar part numbers are retained to identify similar logic functions and electrical ( power and I / O voltage ) compatibility in the different subfamilies.

Standardization of the TTL levels was so ubiquitous that complex circuit boards often contained TTL chips made by many different manufacturers selected for availability and cost, compatibility being assured ; two circuit board units off the same assembly line on different successive days or weeks might have a different mix of brands of chips in the same positions on the board ; repair was possible with chips manufactured years ( sometimes over a decade ) later than original components.

Like most integrated circuits of the period 1965 – 1990, TTL devices were usually packaged in through-hole, dual in-line packages with between 14 and 24 lead wires, usually made of epoxy plastic ( PDIP ) or sometimes of ceramic ( CDIP ).

If a stub resolver queries the caching nameserver for the same record before the TTL has expired, the caching server will simply reply with the already cached resource record rather than retrieve it from the authoritative nameserver again.

The 7407 TTL device, an open collector buffer, simply outputs whatever it receives as input, but as an open collector device, the output is left effectively unconnected when outputting a " 1 ".

The FA also used the ultra-fast, bearing-mounted, honeycomb-patterned, titanium-bladed shutter and through-the-lens ( TTL ) off-the-film ( OTF ) electronic flash automation of the FE2, but added a digital liquid crystal display ( LCD ) information panel at the top left of the viewfinder to indicate the readings of the built-in, open aperture, through-the-lens ( TTL ) light meter versus the actual camera settings.

* Low-power Schottky TTL ( LS ) – used the higher resistance values of low-power TTL and the Schottky diodes to provide a good combination of speed ( 9. 5ns ) and reduced power consumption ( 2 mW ), and PDP of about 20 pJ.

The video system used part of the main memory and TTL logic to provide video and synch to an internal 5-inch monochrome monitor.

TTL is designed to provide a smooth ride while delivering responsive handling and minimizing body lean.

The main disadvantage of TTL with a simple output stage is the relatively high output resistance at output logical " 1 " that is completely determined by the output collector resistor.

The main advantage of TTL with a " totem-pole " output stage is the low output resistance at output logical " 1 ".

In some cases ( e. g., when the output of a TTL logic gate needs to be used for driving the input of a CMOS gate ), the voltage level of the " totem-pole " output stage at output logical " 1 " can be increased up to V < sub > CC </ sub > by connecting an external resistor between the V < sub > 3 </ sub > collector and the positive rail.

The maximum value of this current is about 1. 6 mA for a standard TTL gate.

* Low-power TTL ( L ), which traded switching speed ( 33ns ) for a reduction in power consumption ( 1 mW ) ( now essentially replaced by CMOS logic )

) 1 × TTL serial port 1 × TTL / RS-232 serial port ( configurable )

Has TTL exposure, aperture priority and manual exposure, electronic shutter and two mechanical speeds of 1 / 60 and 1 / 125.

The PALM processor was an entire circuit board containing 13 square metal-can bipolar gate arrays, 3 conventional DIP transistor-transistor logic ( TTL ) parts and 1 round metal can part.

* Flash control: TTL flash control by combined five-segment TTL Multi Sensor with single-component IC and 1, 005-pixel RGB sensor ; i-TTL Balanced Fill-Flash with SB-800 / 600 ; Film speed range in TTL auto flash: ISO 25-1000

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.

* A TTL of 1 means you only can ask the peers you know and they cannot ask further.

* ( fr ) Chamchiev, Tchinguiz ( 2009 ), Stabilité et instabilité monétaire: analyse du processus cumulatif de Wicksell en termes de circulation monétaire, Thèse de doctorat, Université Pierre Mendès France de Grenoble 2, http :// www. sudoc. abes. fr / xslt / DB = 2. 1 / SET = 5 / TTL = 1 / SHW? FRST = 4

Older systems such as TTL used 5 volts, newer computers typically use 3. 3 volts ( LV-TTL ) or even 1. 8 volts.

The major improvements in the FE2 compared to the FE are silicon photodiode light meter sensors, internal printed circuit electronics, provision for through-the-lens ( TTL ) off-the-film ( OTF ) electronic flash automation ( essentially identical to the system introduced in the Nikon FG in 1982 ) and a quartz oscillator timed, bearing-mounted, titanium-bladed shutter reaching an ultra-fast top speed of 1 / 4000th second ( plus world's fastest X-sync to 1 / 250th second ).