UC2524A: Is there any document or application note that CL+,CL- terminal usage can be known?

Kazuya Nakai59

Part Number: UC2524A
Other Parts Discussed in Thread: UC2524, UC1524A

Hello guys,

One of my customers is looking for any document or application note that CL+,CL- terminal usage can be known because they don't know well how to connect CL+,CL- terminals of UC2524A.

Do you have any document which has whole schematic using UC2524A?

Your reply would be much appreciated.

Best regards,

Kazuya Nakai.

over 6 years ago

0 John Griffin1 over 6 years ago

TI__Mastermind 34465 points

Hello Kazuya Nakai,
The UC2524A uses these pins as the overcurrent comparator to stop the PWM output.
CL+ and CL- are connected to a small current sense resistor,R.
Also connect CL- to GND and connect CL+ to the return path for your DC input power.
This resistor sets the current limit for your application.
The current limit = 0.2/R

Hope this answers your question.
Regards
John

0 Kazuya Nakai59 over 6 years ago in reply to John Griffin1

Guru 21505 points

Hello John,

Thank you for the prompt reply.

Can schematics shown in UC2524 datasheet be applied to UC2524A?
www.ti.com/.../uc2524.pdf

Thank you again and best regards,
Kazuya Nakai.

0 Kazuya Nakai59 over 6 years ago in reply to Kazuya Nakai59

Guru 21505 points

Hello John,

Let me ask you again in other words.

Can UC2524A be used with figure 6 or 7 in UC2524 datasheet?

Also in Figure6, UC1524 CL+ (No.4) is connected to GND (No.8). My understanding is that PWM switching is stopped by pulling OSC OUT signal to GND internally when CL-（No.5) voltage is less 200mV than GND. Is my understanding correct?

Thank you and best regards,
Kazuya Nakai.

0 John Griffin1 over 6 years ago in reply to Kazuya Nakai59

TI__Mastermind 34465 points

Hello Kazuya Nakai,

The UC1524A is an improved version of the UC1524 and is fully interchangeable.

There is an error in the datasheet for the UC1524

Pin 5 is connected to the non inverting input of the current amplifier as shown in the block schematic (attached)

So for the current limit to trip pin 5 is connected to GND and the voltage on pin 4 needs to increase with load.

Use the data sheet for the UC2524A.

Regards

John

0 Kazuya Nakai59 over 6 years ago in reply to John Griffin1

Guru 21505 points

Hello John,

I can see that no.4 pin is connected to non-inverting pin of CL comparator in the connection diagram on page 2 in UC1524 datasheet. You said this connection is an errors, isn't it?

Also two schematics, Figure 6 and 7 in UC1524 datasheet don't have any error, do it?

Thank you and best regards,
Kazuya Nakai.

0 John Griffin1 over 6 years ago in reply to Kazuya Nakai59

TI__Mastermind 34465 points

Hello Kazuya,
Yes that is correct.
The pin labelled "+SENSE" goes to the inverting input.
Regards
John

0 John Griffin1 over 6 years ago in reply to John Griffin1

TI__Mastermind 34465 points

Hello Kazuya,
I am closing this thread because the information you requested has been extensively provided.
If you a have new further question please open a new thread.
Regards
John

0 Kazuya Nakai59 over 6 years ago in reply to John Griffin1

Guru 21505 points

Hello John,

Thank you for your strong support.
I will open a new thread if I have any question.

Thank you again and best regards,
Kazuya Nakai.

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UC2524A: Is there any document or application note that CL+,CL- terminal usage can be known?