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For the working of TTL nand with totempole
When both inputs are LOW
The emitter base junctions at A and B gets forward biased, base -collector junction gets reverse biased for Q1.So maximum current flows through forward biased junction. As base -collector junction of Q1 gets reverse-biased, base current through the Q2 is ZERO, which makes Q2 OFF. As Q2 is in OFF state, base current through Q4 is ZERO, which makes Q4 OFF.As Q2 is in OFF state the current through R2 flows through base of Q3 which makes Q3 and diode D to ON.As Q4 is in OFF state the current flows through the load, which make output to go HIGH state
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What is active pull up in TTL NAND gate?
All standard TTL devices use a two transistor "totempole" output, one transistor provides an active pull down and the other an active pull up. Only one of these transistors is on at a time and one or the other is always on. Open collector TTL devices omit the active pull up transistor so that several outputs can be "wired" together and an external resistor provides a passive pull up. The only problem with this is the risetime of a passive pullup is much longer than the risetime of an active pull up, making the circuit slower. Tristate TTL devices have the same two transistor "totempole" output as standard TTL devices, but the circuits that control these transistors are more complex allowing a "third state" in which both transistors are turned off, leaving the output of the device floating. This allows many tristate TTL devices to be connected to a single line with only one actually driving it at a time (preventing conflicts with one device pulling up and another pulling down).
Ttl nand gate?
The TTL Nand gate is usually used in the design of various electric circuits.
Why an open ttl gate behaves as a logic high input?
because TTL have a bias input setup to eliminate noise therefore the output will follow the logic one input if left open
What is a TTL-compatible output?
Compatibility in TTL means that the output of one TTL device can be used to drive the Input of the other TTL device , This because the low and high output window fit inside the low and high input window/profile TTL stand for Transistor Transistor Logic, so any voltage between 0 and 5 volt is compatible where any voltage between 3V and 5V is logic 1 and zero volt is logic 0
What is a TTL compatible output?
A: TTL gates operates on the premise of having +5 dc on the rail therefore the output will be in the range +5 volts. A cmos gate while similar to a TTL function is not really compatible since the output volts can be 12 volts or more. Besides that TTL gates require some input current for it to operate
How NAND gate works?
A: NAND implies not and to be true both input must be hi or true <> There are two flavors of NAND gate. The positive input/negative output NAND will have a low output if and only if both inputs are high. The negative input/positive output NAND will have a high output if and only if both inputs are low.
Why is a TTL logic gate faster than a CMOS logic gate?
The switching time (on and off) of the TTL logic gate is very fast in comparison with CMOS logic gate. However, they could not tolerate higher range of power supply.
What are the advantage of schottky TTL?
High speed operation.
What is 7432 ic?
The 7432 is a quad two input OR gate with TTL levels.
Ic number of or gate?
Ttl: 7432, 744075cmos: 4071
Ttl logic family has an output state known as?
true and false
What type of gate is the 74LS00?
The 74LS00 is a quad two input NAND gate with low power schottkey TTL implementation.
