# NE522(High-speed dual-differential comparator/sense amp)

#### karas

Joined Sep 8, 2011
211
What is the function of strobe s and strobe g in this ic,AND HOW THIS CHIP WORKS

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#### tom_s

Joined Jun 27, 2014
288
http://pdf.datasheetcatalog.com/datasheet/philips/NE522N.pdf

been a long long time since i've played with logical gates, ones i've used lately have steel hinges

looking at the ic block diagram - i forget what the triangles are -

strobe 1g and strobe s are 2 parts of a 3 input NAND gate for output 1.

strobe 2g and strobe s are 2 parts of a 3 input NAND gate for output 2.

anyone else feel free to correct, i also get AND's and NAND's mixed

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#### karas

Joined Sep 8, 2011
211
http://pdf.datasheetcatalog.com/datasheet/philips/NE522N.pdf

been a long long time since i've played with logical gates, ones i've used lately have steel hinges

looking at the ic block diagram - i forget what the triangles are -

strobe 1g and strobe s are 2 parts of a 3 input NAND gate for output 1.

strobe 2g and strobe s are 2 parts of a 3 input NAND gate for output 2.

anyone else feel free to correct, i also get AND's and NAND's mixed
if input 2A AND INPUT 2B IS<-VOS THIS MEAN THAT THE OUTPUT OF THE INVERTER WILL BE HIGH AND THE STRS AND STRG ARE HIGH SO THE OUTPUT 2Y WILL BE LOW
AND IF VID (INPUT 2A AND INPUT 2B) ARE (-VOS<VID<VOS) WHAT WILL BE THE OUTPUT OF THEI NVERTER(DIAGRAM IN THE FIRST PAGE)AND WHAT IS THE CASE WHEN THE 2 INPUTARE>VOS

#### tom_s

Joined Jun 27, 2014
288
i do apologies, i don't exactly understand your questions

first thing i would be doing is looking at the truth table. this illustrates what state the output pins are for input conditions.

http://1.bp.blogspot.com/-4ESBWCTs05g/Tmdkg_eMUfI/AAAAAAAAAR4/nwyoVxPWLpU/s1600/NAND2.jpg

there are 2 NAND gates on the IC with 3 inputs in each

all 3 inputs of the NAND gates must be high for the output to be low. if any other state, the output is high.

strobe s is common to both NAND gates meaning both gates will be getting a high or low signal at the same time.

digital is high or low (on/off), there is not 1/2 way point.

is logical spock

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#### ericgibbs

Joined Jan 29, 2010
17,440
hi karas,
The NE522 is a Dual IC, the Outputs are Open collector.

Strobe 1G controls Output 1Y transistor and Strobe2G controls Output 2Y transistor.

Strobe S, controls both 1Y and 2Y outputs.

A High on a Strobe pin 1G will will 'Enable' the Y1 output transistor , a Low will 'Disable' the output transistor. Likewise for the Strobe 2G, Y2 output.

A Low on the Strobe S pin will Disable BOTH Y1 and Y2 output transistors.

E