This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM231: Minimum Pulse Width

Part Number: LM231

The data sheet does not really describe in detail the minimum pulse width that the device can see in a frequency to voltage mode. It appears that the frequency is rather low (~10k), but do we have any information on the minimum pulse width that the customer can use?

Thanks for your help with this!

Richard Elmquist

  • Hi Richard,

    The only information we have for the LM231 is the datasheet. Based on the datasheet F-V applications (Figs. 18 and 19) and typical characteristics curves it is certainly usable up to 10 kHz. The Electrical Characteristics table lists the Rated Full-Scale Frequency with is 10.0 kHz, with VIN = −10 V (V-F mode).

    Figure 7. provides a graph of 100 kHz Non-Linearity Error implying that the device is usable to 100 kHz, as one of the opening page bullets also indicates. Other F-V converters I have worked with have similar F-V and V-F high end frequencies so the LM231 might be able to be able to support 100 kHz F-V operation. The electrical performances are likely degraded compared to 10 kHz and lower operation.

    Since the datasheet doesn't provide much information about operating the LM231 at frequencies above 10 kHz , it may be best to err to the conservative side when it comes to a minimum pulse width. Using 100 kHz as the maximum F-V frequency and assuming a 50 % duty cycle, the pulse high (and low) time would be 50 us. That should be usable when the F-V conversion frequency is lower than 100 kHz.

    Regards, Thomas
    Precision Amplifiers Applications Engineering

  • Thomas,
    Thanks for your help with this!
    Have a great weekend.
    Richard Elmquist