The HD-6409 Manchester Encoder-Decoder (MED) is a high

speed, low power device manufactured using self-aligned

silicon gate technology. The device is intended for use in

serial data communication, and can be operated in either of

two modes. In the converter mode, the MED converts Non

return-to-Zero code (NRZ) into Manchester code and

decodes Manchester code into Nonreturn-to-Zero code. For

serial data communication, Manchester code does not have

some of the deficiencies inherent in Nonreturn-to-Zero code.

For instance, use of the MED on a serial line eliminates DC

components, provides clock recovery, and gives a relatively

high degree of noise immunity. Because the MED converts

the most commonly used code (NRZ) to Manchester code,

the advantages of using Manchester code are easily realized

in a serial data link.

In the Repeater mode, the MED accepts Manchester code

input and reconstructs it with a recovered clock. This

minimizes the effects of noise on a serial data link. A digital

phase lock loop generates the recovered clock. A maximum

data rate of 1MHz requires only 50mW of power.

Manchester code is used in magnetic tape recording and in

fiber optic communication, and generally is used where data

accuracy is imperative. Because it frames blocks of data, the

HD-6409 easily interfaces to protocol controllers.

Features

• Converter or Repeater Mode

• Independent Manchester Encoder and Decoder

Operation

• Static to One Megabit/sec Data Rate Guaranteed

• Low Bit Error Rate

• Digital PLL Clock Recovery

• On Chip Oscillator

• Low Operating Power: 50mW Typical at +5V

• Pb-Free Available (RoHS Compliant)