help with IC name

[TuralH]

Hi everyone,
I have a circuit board with two ICs on it. One of them is a 555 timer. The second IC has its markings erased. The 555 generates a PWM signal, which is fed into pin 13 of the unknown IC.
On pin 1 of this unknown IC, I get a sawtooth waveform.
There is a capacitor connected between pins 1 and 2. Additionally:

• Pin 1 is connected through a resistor to 5V (pull-up).
• Pin 2 is connected through a resistor to ground.

The unknown IC is in a TSSOP-14 package. Pin 7 is ground (GND) and pin 14 is VCC (power supply).
At first, I thought it might be a CD4066, but this IC usually works as an analog switch, and not quite in the way I'm observing here.
Does anyone have an idea what this IC could be?

 

[danadakk]

Sounds like OpAmp used as an integrator used to convert timer output to triangle
wave.....?

OpAmp package, if thats what it is, could be a quad in a 14 pin package.

 

[TuralH]

Sounds like OpAmp used as an integrator used to convert timer output to triangle
wave.....?

OpAmp package, if thats what it is, could be a quad in a 14 pin package.

yes the package is tssop-14 but I dug through the entire internet and did not find an operational amplifier that would have a connection at least 1 2 and 13 pins, i stoped at cd4066 but i dont know can it work in this case

 

[danadakk]

Could be a LM3900 or OpAmp Transconductance amp like a LM13700....

You could look at package top under UV light, might reveal, hard to say.

 

[TuralH]

Could be a LM3900 or OpAmp Transconductance amp like a LM13700....

You could look at package top under UV light, might reveal, hard to say.

yes, I'll try under UV but they erased it so it will be hard to understand but I'll try

 

[danadakk]

yes, I'll try under UV but they erased it so it will be hard to understand but I'll try

Do you know overall function of design, what was object of interest used for ?

 

[TuralH]

Do you know overall function of design, what was object of interest used for ?

for control VCO, first PWM to Sawtooth and sawtooth drives VCO