Power supply unit:
It is responsible to provide a power supply to the set-top box by using various standalone adapters. These adapters convert input AC (110 to 220 volt) to DC (5 to 12 volt) and distribute this supply to different inner units of set-top box.
Smart card slot:
This unit holds a smart card. The smart card is also used to decrypt different channels.
Receiver front end:
This part of STB (Set-Top Box) is mainly responsible to perform the below functions:
- Receiving the broadcasted signal from the satellite
- Demodulate the received signal
- Send this demodulated signal to the STB decoder circuit
It is a central processing part of the STB. As per the current generation of set-top boxes, most of the features are integrated with STB decoder chips. It is a kind of system integration that is also known as a system on chip (SOC). Set-top box SOCs have a large number of inbuilt video decoders, de-multiplexers, demodulators, etc. and some peripherals like USBs.
As we are already aware with RAM (Random Access Memory). In STB RAM is responsible to hold data like audio and video information in buffer memory to provide continuous streaming or flow of your favorite programs. In normal set-top boxes, the RAM size limit is 32 MB whereas in HD set-top boxes its size is 256 MB. Some of the set-top boxes also provide ROM memory or a hard disc to record your programs.
RF modulator is mainly used to provide RF signal by using received audio and video signal. It is mainly used to generate RF signal for old Television models those have only RF input.
It stores boot loader, main set-top box applications, and some non-volatile information of viewers. Flash memory sizes in STBs are varying from 8 to 64 MB.
This slot provides to support different CAS (Conditional Access Schemes). DVB-CI card slot is responsible to provide several conditional schemes. The DVB-CI card decrypts the channels encrypted by CAS as per their plan or schemes.
Thanks for reading. See you soon with another exploration!