Oversampled ADC based on pulse frequency modulator and TDC

Oversampled ADC based on pulse frequency modulator and TDC

For access to this article, please select a purchase option:

Buy article PDF
(plus tax if applicable)
Buy Knowledge Pack
10 articles for £75.00
(plus taxes if applicable)

IET members benefit from discounts to all IET publications and free access to E&T Magazine. If you are an IET member, log in to your account and the discounts will automatically be applied.

Learn more about IET membership 

Recommend Title Publication to library

You must fill out fields marked with: *

Librarian details
Your details
Why are you recommending this title?
Select reason:
Electronics Letters — Recommend this title to your library

Thank you

Your recommendation has been sent to your librarian.

Oversampled converters based on voltage controlled ring oscillators are an attractive solution because of their digital implementation and simplicity. However, the voltage-to-frequency conversion of ring oscillators displays a poor linearity. Replacing the ring oscillator by a pulse frequency modulator (PFM) that provides improved linearity at the expense of feedback and analogue amplification is proposed. Compared to the equivalent continuous time sigma–delta modulators, the PFM may be more tolerant to circuit impairments. In addition, the output data of the proposed architecture is a multibit sequence through the use of a time-to-digital converter TDC instead of a Flash quantiser or a multibit digital-to-analogue converter. A high dynamic range can be achieved without severe constraints on analogue mismatch or clock jitter.


    1. 1)
    2. 2)
    3. 3)
      • 3. Hernandez, L., Prefasi, E., Paton, S., Rombouts, P.: ‘Analysis of VCO based noise shaping ADCs linearized by PWM modulation’. IEEE Int. Conf. Electronic, Circuits and Systems (ICECS), Seville, Spain, December, 2012, pp. 352355.
    4. 4)
      • 4. Fitch, E.: ‘The spectrum of modulated pulses’, J. Inst. Electr. Eng., Part IIIA: Radiocommun., 1947, 94, (13), pp. 556564.

Related content

This is a required field
Please enter a valid email address