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What type of this IC part number? [need help]

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coolpixs4

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Dear Expert,

Is there anyone who knows or has knowledge about this IC ?, I want to know its part number or a similar IC function (it doesn't have silk screen name on top of the IC so I don't know its name, but I know its functions)

Its function is a one-shot random pulse generation IC which is used in "Remote keyless control" device.

Pin 1: Vcc
Pin 2: LED
pin 3: DO (random Clk data pattern output based on SW1~SW4 one-shot pressed)
pin 4: SW1 (H/L level -H=3V, L=0V)
pin 5: SW2 (pin 4~pin 7 standby are at H level, when pressed button it short to ground => L level, then the DO (data output) is at pin 3
pin 6: SW3
pin 7: SW4
pin 8: Vss(Gnd)

I have attached some screenshots below
The clock data output has different patterns (0010010011010010010011...)based on which SW is pressed width the pulse with is about 360ms (~3kHz)

Thank in advance.

* I am looking for an IC with the data output has its pulse width of about ~8KHz or more
 

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Last edited:

Hi,

Sounds like an 8 pin microcontroller. Maybe PIC 12Fxxx.

So even if you knew it's exact type you still need the according code.

Klaus
 
Dear Expert,

Is there anyone who knows or has knowledge about this IC ?, I want to know its part number or a similar IC function (it doesn't have silk screen name on top of the IC so I don't know its name, but I know its functions)

Its function is a one-shot random pulse generation IC which is used in "Remote keyless control" device.

Pin 1: Vcc
Pin 2: LED
pin 3: DO (random Clk data pattern output based on SW1~SW4 one-shot pressed)
pin 4: SW1 (H/L level -H=3V, L=0V)
pin 5: SW2 (pin 4~pin 7 standby are at H level, when pressed button it short to ground => L level, then the DO (data output) is at pin 3
pin 6: SW3
pin 7: SW4
pin 8: Vss(Gnd)

I have attached some screenshots below
The clock data output has different patterns (0010010011010010010011...)based on which SW is pressed width the pulse with is about 360ms (~3kHz)

Thank in advance.

* I am looking for an IC with the data output has its pulse width of about ~8KHz or more
Thank you so much
That's what I need, It doesn't matter. I can reprogram IC to get data output at 8KHz
The IC is

PIC12F683-I/P - PIC12F683 Flash 8-Pin 2kb 8MHz Microcontroller​

 

Functionally it is probably like the HCS200, a code hopping key. The data isn't random, it wouldn't be of much use if it was! They work on the principle of sending a sequence of bits that follow a special algorithm. The decoder checks the sequence is valid after being fed through the algorithm but unless the exact code is known, anyone intercepting the data stream just sees unconnected bits. Each transmission looks random so finding how it relates to the one before it is very difficult.

Brian.
 
Based on the OOK/ASK modulation

1642644797331.png


1642644950124.png


To reduce the Adj channel leakeages (offset 12.5KHz/BW=8.5KHz) ,
it should be ... slower symbols or smoother symbols
1642644878374.png
Or
1642644891179.png


Then, how do I can control OSC2/CLKOUT data rate at lower/higher frequency ? without using extra component such as LTC6993 IC

Recent, the CLKOUT is at T=360us (about 2.778KHz)
I want to make it slower at T=800us (about 1.25kHz), what can I do ?

I have read thru the datasheet of all

PIC12F6xxx Flash 8-Pin Microcontroller

but nowhere to tell how we can control the OSC2/CLKOUT data rate?

Thank for any comments
 

Recent, the CLKOUT is at T=360us (about 2.778KHz)
1642669236011.png

I want to make it slower at T=800us (about 1.25kHz), what can I do ?
 

Hi,
but nowhere to tell how we can control the OSC2/CLKOUT data rate?
What do you mean with "data rate"?

According datasheet Table 1-1 it says:
* OSC2: Output of oscillator for XTAL/Resonator
* CLKOUT: Output of Fosc/4

--> It is no "data", it is just a square wave..

Klaus
 

Recent, the CLKOUT is at T=360us (about 2.778KHz)
I want to make it slower at T=800us (about 1.25kHz), what can I do ?
You are asking how to modify the code flashed into the PIC processor. Presumed you don't have the source or at least a hex file and the flash is protected - there's no way, unfortunately.
 
Hi,

What do you mean with "data rate"?

According datasheet Table 1-1 it says:
* OSC2: Output of oscillator for XTAL/Resonator
* CLKOUT: Output of Fosc/4

--> It is no "data", it is just a square wave..

Klaus
You are right, it is a square wave at the OSC2/CLKOUT (the pulse width of duaration T=360us for 'one symbol') but it is not a simple squarewave of a series '1' & '0' : 0101010101010101...

It is hardcoded to include data, such as if GP0/GP1/GP2/GP3 (equivalent to 4 buttons) at standby mode (H-level ~3V) => no CLKOUT
if GP3 is short to ground (L-level ~0V) => the CLKOUT will be a form of 0011010100011... (a pattern of '1' & '0')
if GP2 is short to ground (L-level ~0V) => the CLKOUT will be a form of 0101101101101... (yeah, I though that's not a randomly)
...

As I checked the IC above, the pulse width is T=360us (f=2.778KHz for symbol 1)
But, by reviewing several MCU 8-pins 8-bits IC datasheet, the internal OSC with minimum Fosc =32KHz ~10MHz, * CLKOUT: Output of Fosc/4 => how did it get 2.778KHz/symbol ? Except for that is not PIC12F6xxx

I want to slow down the symbol rate to get better adj-channel leakage, for example pulse duaration T=800us (f=1.25KHz)

Thanks !

Of course, I can use extra IC such as LTC6993 for this purpose
1642725130261.png
 
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