TTL Digital Circuit | Electronic Project Circuits

Posts Tagged ‘TTL digital circuit’

LED status TTL logic high low circuit

This is a cycle high or low status of the digital logic signal. Since the 5V power supply is ideal for TTL digital And the circuit to clearly display text. Is easy to see the value.
Operation of the circuit is in normal state or input into Low. And it IC1 to a High state to stimulate Q1 to work with the pressure to drop across R2. That the diodes D1,D2, D3, and connect the LED 7 Segment to display the letter “L” out. If the input is marked High, it makes IC1 return status is Low the Q1 does not work, but will flow from the input through R5, R6 entry. 7 Segment and through R3, R4, D4, D5 to 7 Segment as well. the 7 Segment display letters “H” up. and the cycle will have a resistor R7 is connected with to help reduce the current flow to LED 7 Segment. It prevents damage crash.

Be the first to comment - What do you think? Posted by admin - November 30, 2010 at 7:39 am

Categories: Digital, Meter Tags: digital logic probe, state logic, TTL digital circuit

Sine Wave To TTL Converter

As the title implies, the present circuit is intended to convert sinusoidal input signals to TTL output signals. It can handle inputs of more than 100 mV and is suitable for use at frequencies up to about 80 MHz. Transistor T1, configured in a common-emitter circuit, is biased by voltage divider R3–R5 such that the potential across output resistor R1 is about half the supply voltage. When the circuit is driven by a signal whose amplitude is between 100 mV and TTL level (about 2 V r.m.s.), the circuit generates rectangular signals. The lowest frequencies that could be processed by the prototype were around 100 kHz at an input level of 100 mV, and about 10 kHz when the input signals were TTL level.
Resistor R6 holds the input resistance at about 50 ?, which is the normal value in measurement techniques. It ensures that the effects of long coaxial cables on the signal are negligible. If the converter is used in a circuit with ample limits, R6 may be omitted, whereupon the input resistance rises to 300 ?.
Source: http://www.extremecircuits.net/2010/06/sine-wave-to-ttl-converter.html

Be the first to comment - What do you think? Posted by admin - August 30, 2010 at 10:48 pm

Categories: Converter Circuit, Digital Tags: analog to digital converter, sine wave converter square wave, TTL digital circuit

Digital Isolation up to 100 Mbits

When it is necessary to send a digital signal between two electrically isolated circuits you would normally choose an optoisolator or some form of transformer coupling. Neither of these solutions is ideal; optocouplers run out of steam beyond about 10 MHz and transformers do not have a good low frequency (in the region of Hertz) response. The company NVE Corporation (www.nve.com) produces a range of coupler devices using an innovative ‘IsoLoop’ technology allowing data rates up to 110 Mbaud. The example shown here uses the IL715 type coupler providing four TTL or CMOS compatible channels with a data rate of 100 Mbit/s. Inputs and outputs are compatible with 3.3 V or 5 V systems. The maximum isolation voltage is 2.5 kV and the device can cope with input transients up to 20 kV/µs.
The company produce many other configurations including bidirectional versions that would be suitable for RS485 interfacing. The IsoLoop coupler is based on relatively new GMR (GiantMagnetoResistive) technology. The input signal produces a current in a planar coil. This current generates a magnetic field that produces a change in resistance of the GMR material. This material is isolated from the planar coil by a thin film high voltage insulating layer. The change in resistance is amplified and fed to a comparator to produce a digital output signal. Differences in the ground potential of either the input or output stage will not produce any current flow in the planar coil and therefore no magnetic field changes to affect the GMR material. Altogether the circuit provides a good electrical isolation between input and output and also protects against input signal transients (EMV).
Author: Gregor Kleine – Copyright: Elektor July-August 2004
Source: http://www.extremecircuits.net/