RF Built-In Self-Test for Integrated Cellular Transmitters

A spectral built-in self test (BIST) solution for integrated cellular RF transmitters is presented that enables on-chip verification of PLL spectral performance. Multi-tone FM test signals with a spurious-free dynamic range (SFDR) of 60 dB are generated without compromising the performance of the RF transmitter itself. The RF signal is demodulated and digitized in an on-chip digital FM discriminator, spectral analysis is performed using digital narrowband filtering. The additional BIST blocks are fully digital and have been implemented on a chip area of only 0.05 mm2 in a 130 nm CMOS technology. The test blocks allow fast measurement of PLL frequency response, level of spurious sidebands and in-band phase noise down to -80 dBc without external test equipment. Catastrophic faults and most parametric faults can be detected as long as they influence the loop bandwidth or deteriorate spectral performance.