Hi Everyone,

I recently made a 3 stage amplifier on dotted pcb with TLV9002 opamps. However the circuit didn't work. I have a doubt whether i made a currect connection with the opamp pin. I have provided the image of the opamp below.

The opamp has white line instead of dot notation. How to identity the pins (especially pin 1)? Does the line represent the top side of opamp with pin1 on the top left corner?

Thankyou

 

I would think so.
Is that how you connected it?
Where did you purchase these chips?
Post schematic of this amplifier.

 

Yes, i have connected it assuming the line represents the top side of the IC.

 

What about my other questions.

 

There are only two possible orientations. As there are ESD diodes on all signal input and output pins (the other end of the diode connected to VCC or GND). You may try using a Ohm-meter to check the resistance between any signal pin to an unkown VCC-or-GND pin, in both directions. The two readings are different based on the ESD direction, and thus telling whether the unknown pin is VCC or GND.

 

 

What the manufacturer dathasheet says?

 

A supply voltage of 1.8 - 5.5 is recommended.
The datasheets gives tests were conducted with plus and minus 2.75 V or 5.5V, could be less.
A safe input less than 10mA through a 5K resistor is recommended.
The output should look like the graphs provided.
TLV900x Low-Power, RRIO, 1-MHz Operational Amplifier for Cost-Sensitive Systems datasheet (Rev. R)

 

Hi Everyone,

I recently made a 3 stage amplifier on dotted pcb with TLV9002 opamps. However the circuit didn't work. I have a doubt whether i made a currect connection with the opamp pin. I have provided the image of the opamp below.

The opamp has white line instead of dot notation. How to identity the pins (especially pin 1)? Does the line represent the top side of opamp with pin1 on the top left corner?

Thankyou

The chamfer on the left side in your image also denotes the low numbered pins, starting from pin 1 at the top left. See the bottom of the datasheet for the SOIC package outline.

 

Where did you buy it? It could be a counterfeit that has had its markings removed.

 

TI uses/used a white line instead of some dot. (Others may have done the same, I just recently stumbled over a TI PCN notifying about a change from the white line to a pin 1 dot for some devices.) On SO* packages the white line is from pin 1 to the pin with the maximum number. Rasmussons' image shows the scheme for an 8-pin device correctly.