74LS25 Dual 4 - Input NOR Gate IC with Strobe

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74LS25 Dual 4 – Input NOR Gate IC is a member of the 74XXYY IC series. The 74LS25 is a TTL (Transistor to Transistor Logic) which uses low power Shottky transistors to reduce the stored charge and get higher switching speeds than with conventional bipolar transistors. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers. The Strobe input forces the output of the NOR gate to go high when the strobe is low. The strobe input is used to ‘strobe’ or toggle the output.

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What is a NOR Gate?

An OR gate followed by a NOT gate in a cascade is called a NOR gate. The inclusive NOR (Not – OR) gate has an output that is normally at logic level “1” and only goes “LOW” to a logic level “0” when any of its inputs are at logic level “1”. The Logic NOR Gate is the reverse or complementary form of the inclusive OR gate.

74LS25 Key Features & Specs

Technology Family: TTL
Min VCC: 4.75V
VCC (Max): 5.25V
No. of Channels: 2
Inputs per channel: 4
IOL (Max): 16mA
IOH (Max): 0.8mA
Input type: Bipolar
Output type: Push-Pull
Max Speed: (tpd 10-50ns)
Max Data rate: 70Mbps
Rating: Catalog
Operating temperature range: 0°C to 70°C

74LS25 Pinout

Pin No	Pin Name	Description
1	A1	INPUT 1 of GATE 1
2	B1	INPUT 2 of GATE 1
3	1ST	Strobe Input of Gate 1
4	C1	INPUT 3 of GATE 1
5	D1	INPUT 4 of GATE 1
6	Q1	OUTPUT of GATE 1
7	GND	Ground
8	Q2	OUTPUT of GATE 2
9	A2	INPUT 1 of GATE 2
10	B2	INPUT 2 of GATE 2
11	2ST	Strobe Input of Gate 2
12	C2	INPUT 3 of GATE 2
13	D2	INPUT 4 of GATE 2
14	Vcc	Chip Supply Voltage