Analysis and Design of a Charge Sampler With 70-GHz 1-dB Bandwidth in 130-nm SiGe BiCMOS
L. Wu, J.C. Scheytt, IEEE Transactions on Circuits and Systems I: Regular Papers 68 (2021) 3668–3681.

Event Driven Modeling and Characterization of the Second Order Voltage Switched Charge Pump PLL
E. Ali, C. Hangmann, C. Hedayat, F. Haddad, W. Rahajandraibe, U. Hilleringmann, IEEE Transactions on Circuits and Systems I: Regular Papers 63 (2016) 347–358.

Stability Analysis of a Charge Pump Phase-Locked Loop Using Autonomous Difference Equations
C. Hangmann, C. Hedayat, U. Hilleringmann, IEEE Transactions on Circuits and Systems I: Regular Papers 61 (2014) 2569–2577.