NXP Dual Tuner RF System Brings Integration Breakthrough to Satellite Set-top Boxes

The pre-tuner circuitry provides the flexibility that allows set-top boxes to be used in dissimilar installation scenarios - either with a single cable input, splitting the signal internally to the device, or in legacy mode with two separated inputs. In both cases, an optional dual loopthrough function is available.

The most common use case for the single input setting is when the set-top box is used with a Single Cable Reception outdoor unit (ODU). In this case, signals from multiple Low Noise Blocks (LNBs) are multiplexed onto a single cable at the ODU. This single cable can then provide the required signals for many set top boxes in a single home or multi-dwelling unit (MDU). With no hardware changes, a set-top box using this IC can also be used in an installation with a legacy multi-LNB, multi-cable ODU. In this legacy installation, each tuner gets its signal from a separate cable.

“The industry trend towards Single Cable Reception has the potential to dramatically reduce installation costs because there are fewer cables to install, but implementing SCR circuitry in a set-top box using a standard satellite tuner is complex and expensive,” said Tim Kirstein, NXP Semiconductors. “We have created the TDA20136 with the highest levels of RF integration to directly address these problems, while also providing the set-top box maker with the flexibility to be backwards compatible with traditional multi-LNB, multi-cable ODUs.”

The TDA20136 system is based on NXP’s proven superior-performance dual-tuner technology, the CX24132. This unique second-generation complete dual 8PSK tuner offers outstanding performance and low power consumption. It includes all necessary Low Noise Amplifiers (LNAs), Voltage-Controlled Oscillators (VCOs), synthesizers, mixers and filters required for common applications, and its small (7mm x 7mm) size allows system designers to reduce the size of front-ends.