UC1524A: OSC External Circuit

Hi,

OSC is for oscillator pulse monitoring - you can use an oscilloscope to check the clock, if you do not need external frequency synchronization.

To set up the oscillator frequency, you just need to have one resistor for RT and one capacitor for CT, tie each from the pin to GND. The values of RT and CT can be found on page 5 of the datasheet, so when you know your frequency, then you can pick up RT and CT values from the chart on that page. It is better to pick up RT and CT with good tolerances with respect to your operation temperature range.

Hi,

You need to design a circuit to generate clock signal to be used for synchronize the devices with its pulse peak about 3.5V and its pulse width about 50% duty of the clock period, the device to be synchronized needs to have RT and CT setup its frequency lower than the external clock frequency about10 to 15%.

Hi,

You can use a typical timer 555 circuit for your intended frequency then connect that circuit to OSC.

Hi,

Please make sure the peak voltage is about 3.5V. No other concerns.

Hi,

(1) if peak voltage at about 3.5V then ok.

(2) No need in general, if the sync signal connection is very far away, I suggest to use twisted pair wire Y and GND.

(3)  OSC to GND has a resistance 2kΩ. For a 3.5V peak, the current OSC requires is 3.5V/2k = 1.75mA.

Yes, based what I know and that is why I mentioned several times to keep it at about 3.5V

Hi,

I suggest change R3 with a 3.3V zener with 2% zener voltage tolerance.

You can also use 3.6V zener but make sure it’s tolerance with max 3.7V

OSC has an internal resistance not a specified parameter so a fixed R3 may not work.