This brief presents a 25-Mbps 4-amplitude-shiftkeying (4-ASK) receiver front-end (RFE) for biomedical data telemetry via a series-resonant capacitive link. The RFE incorporates low-power clock and data recovery (CDR) circuitry for synchronization in which a novel highly linear trans conductance (Gm) cell is employed in the phase detector (PD) to mitigate any possible error decisions while comparing the phase difference between the input and feedback signals. The proposed RFE is fabricated in 65 nm 1P8M standard CMOS, the core circuit occupies 0.11 mm2, and consumes 2.9 mA from 1 V. While conducting ex vivo measurements using beef tissue and a series-resonant capacitive link, the proposed RFE is capable of processing 4-ASK data patterns up to 25 Mbps with bit error rate (BER) less than 10−3 and total jitter of ∼42 ns. Index Terms Amplitude-shift-keying (ASK), capacitive wireless data transfer (C–WDT), clock and data recovery (CDR), receiver front-end (RFE), series-resonant capacitive link.