LM2917-N: LM2917-N for Frequency to Voltage

Hi Rock,

Here's some answers to your questions about the LN2917-N:

1. What are the frequency limits (highest and lowest)?

There is no low frequency limit because the LM2917-N is a dc, direct coupled circuit internally. Although the datasheet doesn't specify a maximum the highest frequency that is referenced in the Electrical Characteristics table is 10 kHz.

2. What is the output type, AC or DC?

The LM2917-N is fundamentally a frequency-to-voltage converter (F-to-V). The output is essentially a dc level that is established by the input frequency. However, as the datasheet explains the output level will have some ripple riding on it. See datasheet pages 14 and and 15. C2 affects the amount of ripple that occurs.

3. If AC output. The Input frequemcy=out frequency? What is the output type? Is it a sine wave or square wave?

The output is a dc level with some small amount of ripple as explained in no. 2. If you configure the LM2917-N as a voltage-to-frequency (V-to-F) converter which can be done, then it produces a pulse type output as the datasheet explains.

Regards, Thomas

Precision Amplifiers Applications Engineering