Matched Balun & Band Pass Filter Johanson Technology 2450BM14E0003 Matched Balun and Band Pass Filter is a 6-pin EIA 0603 ceramic passive device for the Nordic Semiconductor nRF51822 and nRF51422 System on Chip devices (QFN versions). This Johanson front-end passive contains an embedded, specifically designed Band Pass Filter (BPF) to pair with the nRF chipsets for FCC/ETC (+Korea, Japan, China) emissions compliance. This device considerably reduces implementation size area, eliminates RF variability (100% RF tested before T&R), and offers excellent temperature stability (4ppm).