The BCM4752 family is Broadcom’s third-generation multi-constellation GNSS receiver, supporting GPS + GLONASS + QZSS.
The BCM47522 was used in the Samsung Galaxy A8 (Exynos) which was released in 2016.
It is also mentioned on websites such as Jotrin Electronics and Yole Group.
The BCM47521 was announced on 20 Feb 2013 in Electronic Specifier.
The BCM47521 appears in several Samsung phones, tablets, and watches:
The BCM4752 was announced on 21 Mar 2012 in The Verge, then in Apr 2012 by Azertac and Coordinates.
An old page from the Broadcom website can be found on the Wayback Machine.