BLASTbus electronics: general-purpose readout and control for balloon-borne experiments

TL;DR

The paper introduces the second-generation BLASTbus electronics system designed for balloon-borne telescopes, enabling detector readout, attitude control, and cryogenic housekeeping with a flexible, synchronous architecture.

Contribution

It presents a versatile motherboard-daughterboard architecture with integrated DSP and FPGA, adaptable for various sensor and control applications in balloon experiments.

Findings

Successfully deployed at the South Pole

Flown on stratospheric balloons

Supports low-noise detector readout

Abstract

We present the second generation BLASTbus electronics. The primary purposes of this system are detector readout, attitude control, and cryogenic housekeeping, for balloon-borne telescopes. Readout of neutron transmutation doped germanium (NTD-Ge) bolometers requires low noise and parallel acquisition of hundreds of analog signals. Controlling a telescope's attitude requires the capability to interface to a wide variety of sensors and motors, and to use them together in a fast, closed loop. To achieve these different goals, the BLASTbus system employs a flexible motherboard-daughterboard architecture. The programmable motherboard features a digital signal processor (DSP) and field-programmable gate array (FPGA), as well as slots for three daughterboards. The daughterboards provide the interface to the outside world, with versions for analog to digital conversion, and optoisolated digital input/output. With the versatility afforded by this design, the BLASTbus also finds uses in cryogenic, thermometry, and power systems. For accurate timing control to tie everything together, the system operates in a fully synchronous manner. BLASTbus electronics have been successfully deployed to the South Pole, and flown on stratospheric balloons.