A minimally invasive wideband mixed-mode detector for mm-Wave BIST applications

Differential circuits, employed to alleviate performance trade-offs associated with increased levels of system integration, demand leading edge solutions to address testing limitations. As a result, a differential, wideband amplitude detector suitable for built-in-self-test (BIST) applications at RF to millimeterwave (mm-Wave) frequencies is presented. For compatibility with BIST methodologies, a comprehensive analysis, lacking in previous literature, simplifies and classifies the detector´s response into a known type (RMS, Peak) depending on certain operating conditions (operating region, input signal level). Additionally, another novel concept of cross-mode detection error is introduced to supplement characteristics of the differential detector. The detector was implemented in a BiCMOS IBM8HP process and two design variants were characterized. A BJT version features a bandwidth between 100MHz and 17.5GHz. The second design added few improvements to the original topology; innovative common-mode detection capability was included with minimal loading effects to the device-under-test (DUT), the circuit was migrated to MOS transistors, and the bandwidth was extended to 70GHz. Both versions (BJT and MOS) occupy a core area smaller than 0.045mm², with a static power consumption as low as 8μW and exhibit a dynamic range of at least 30dB.