While the modern HDTV’s main feature is its big screen, the tuner determines its performance. The tuner is the system front end that selects the channel and provides the initial sensitivity and selectivity for the input signal.
Tuners used to be small, shielded metal boxes. Today, modern TVs mostly use single-chip tuners. Such tuners also are used in portable TVs, DVD and Blu-ray players and recorders, and cable set-top boxes (STBs).
Based on Silicon Labs’ patented TV tuner architecture, the company’s Si21x8 line of TV tuners further improves performance with best-in-class RF performance and support for all worldwide TV standards while delivering the lowest bill of materials.
The devices represent the state of the art in TV tuner technology based on four generations of patented architectural enhancements. The Si21x8 family includes five TV tuner devices optimized for every TV format—analog, digital, or hybrid.
The tuners improve sensitivity and selectivity performance. RF enhancements enable them to offer the highest tolerance to Wi-Fi and Long-Term Evolution (LTE) cell-phone interference without external filtering components. In addition, the reduced noise floor of the tuner IF output improves the video signal-to-noise ratio (SNR) for analog TV reception.
High-quality analog TV support continues to be an important feature for the TV tuner market. Although a few countries have successfully switched to digital-only broadcasts, more than 95% of today’s TVs must continue to support analog broadcast reception.
In addition, analog-only TVs prevalent in China, India, and Southeast Asia represent about 20% of the global TV market. Analog TV tuners in these regions often require a high tolerance to non-standard analog TV signal conditions. The Si21x8 family’s superior RF performance enables robust analog TV reception, even in the presence of non-standard signal conditions.
The Si21x8 tuners produce a lower bill of materials than all other TV tuners available today because they only require a very low number of inexpensive passive external components. Unlike competing products, they require no balun on the RF input, which helps reduce system cost and complexity.
A new integrated power-on reset monitor and the ability to operate with a single 3.3-V power supply further reduce system cost. In addition, enhanced on-chip electrostatic discharge (ESD) protection saves costs for high-performance TV modules that demand higher ESD immunity. And, the Si21x8 family doesn’t require any external wire-wound inductors, loop filter capacitors, tracking filter inductors, or crystal load capacitors.
The Si21x8 family offers low power consumption (less than 500 mW), so TV and STB makers can meet Energy Star and other energy efficiency standards. These mandates are continually evolving and becoming a more critical factor in component selection. Lower power consumption reduces heat dissipation and power supply requirements, which is especially useful for multi-tuner TV and STB designs.
As with all TV tuner products from Silicon Labs, the Si21x8 family supports all worldwide TV broadcast standards, including NTSC and PAL/SECAM for analog TV and DVB-T2/C2/T/C, ISDB-T/C, ATSC/QAM, and DTMB for digital TV.
For unparalleled flexibility in matching TV tuners with various system architectures, all of the tuners in the Si21x8 tuner family are pin-to-pin compatible and share a single software application programming interface (API). A single module or printed-circuit board (PCB) design, then, can address multiple TV and STB applications for both digital and analog TV.
The lineup includes the Si2128, which is an analog-only tuner that meets NTSC and PAL/SECAM. It uses an external demodulator. The analog-only Si2138 meets NTSC and PAL/SECAM. It uses an internal demodulator. The digital-only Si2148 meets all standards with an external demodulator. The Si2158 digital and analog tuner meets all standards, using external demodulators. And, the Si2178 hybrid digital and analog tuner for all standards includes an analog demodulator (see the figure).
The top-of-the-line Si2178 hybrid analog and digital TV tuner from Silicon Labs covers from 42 to 1002 MHz and handles all of the world’s TV standards. The analog demodulator is internal, while an external digital demodulator for the target standard is needed.
Samples and production quantities of the Si21x8 TV tuners are available now. The Si2178 costs $1.40 in 10,000-unit quantities. The Si2178-A-EVB, Si2158-A-EVB, and Si2148-A-EVB evaluation kits, each priced at $495, provide comprehensive platforms for evaluating Silicon Labs’ TV tuners for TV and STB applications.
