RC5 Decoder with µC

by Martin Clausen (mc AT rotgradpsi DOT de)

The SAA3049A from Philips Semiconductor has been discontinued. Therefor arises the need for a equivalent replacement. This page describes a solution using a 8051 MCU.

Table of contents:


Comparison SAA3049A - MCU solution

ParameterSAA3049AMCU solution
Vcc2.5V - 5.5V2.7V - 6.0V
Icc max. @ 3V0.7mA2mA
Iol sink pin-12mA-20mA
Iol sink chip-100mA-80mA
pullup resistorexternalweak internal, except P1.0 & P1.1
some application may require an additional stronger external pullup
reset circuitresistor, cap, diodecap
mode selectionvia ack pin circuitdedicated mode pin
  • Low: output of address and data
  • High: comparison of given address and output of data
address inputnon invertedinverted (closed switch to GND = 1)
IR-codeREC80 or RC5RC5 only, no code selection pin


Download of Program and Circuit

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The part description in schematics is read as follows:
part type + value in exponential form + package description + subpart number in package
for example: C1040805,1 means Capacitor, 100nF, package SMD 0805, first subpart in package

Disclaimer: No warranty at all!
Copyright by Martin Clausen, Germany.
Contact the author: mc AT rotgradpsi DOT de