Rev. 1.00

4

May 07, 2012

HT62104

Functional Description

TheHT62104Infraredremotecontrolencoderpro-

videsameansforeasyremotecontrolsignalencod-

ing.Asallfunctions,includingthesystemoscillator,

areintegratedwithinthedevice,theadditionofexter-

nalswitchesandanIRLEDisallthatisrequiredto

implementafullInfraredremotecontroltransmitter

function.

Thedevicewillgenerateanencodedsignalonitsout-

putpin,DOUT,composedofaStartcode,aCustom

codeandaDatacode.Thesignalisautomatically

K1~K8,changesstatefromhightolow.Theinternal

pull-highresistorskeepthesedatainputpinsina

normallyhighcondition.Theoutputsignalonthe

DOUTpincanbeinterfacedtoanexternalIRLED

forwirelesssignaltransmission.

Signal Generation

ThedevicewillencodeandtransmitaStartcode,a

CustomcodeandaDatacodeuponreceiptofatrigger

signal.Thetriggersignalisahightolowtransition

onanyofthedatainputpins,K1~K8.Thepinsare

normallykeptatahighlevelbytheinternalpull-high

resistors.

Key Input Trigger

TheSignaltransmissionisinitiatedwhenanyofthe

keydatainputpinschangesstatefromhightolow.

Ifthepulsewidthofthetriggersignalderivedfrom

thekeyinputs,K1~K8,islessthanorequalto32ms,

therewillnosignaloutputontheDOUTpin.Ifthe

pulsewidthofthetriggersignalisgreaterthan32ms

andlessthanorequalto4-framewidths,thenaframe

coderepeated4times,dependinguponwhichkey

inputispulledfromahighstatetoalowstate,will

begeneratedontheDOUTpin.Ifthetriggeredsignal

pulsewidthisgreaterthan4-framewidthsandless

thanorequalto8-framewidths,thenaframecodewill

begeneratedandrepeated8timesontheDOUTpin.

K1 ~K8

DOUT

32 ms

32 ms < active

4 Frame

4 Frame < active

8 Frame

Note:1.Thekeydatainputlowsignalpulsewidthmustbegreaterthana32msdurationforafullsignal

transmission,whichconsistsofaspecificrepeatedframecode,tooccur.Iftheinputlowsignalislessthan

orequalto32ms,thennosignalwillbetransmitted.

2.“Frame”indicatesaspecificframecodewhichisdeterminedbythetriggeringkey.

Frame Format

Therearefourframesthattheencodergeneratesforeachavailablesendingtrigger.Theframecodecontainsthree

fieldsincludinga3-bitStartcode(110),a2-bitCustomcode(C1,C2)anda7-bitDatacode.Eachkeydatainput

correspondstoaspecifictransmissioncodeshowninthefollowingtable.

Frame Code Table

Key

Start Code (S)

Custom Code (C)

Data Code (D)

S2

S1

S0

C1

C2

D6

D5

D4

D3

D2

D1

D0

K1

1

1

0

C1

C2

0

0

0

0

0

0

1

K2

1

1

0

C1

C2

0

0

0

0

0

1

0

K3

1

1

0

C1

C2

0

0

0

0

1

0

0

K4

1

1

0

C1

C2

0

0

0

1

0

0

0

K5

1

1

0

C1

C2

0

0

1

0

0

0

0

K6

1

1

0

C1

C2

0

1

0

0

0

0

0

K7

1

1

0

C1

C2

1

0

0

0

0

1

1

K8

1

1

0

C1

C2

1

0

0

0

1

1

0

TheC1andC2pinsareinternallyconnectedtopull-highresistorswhosestatusaredecidedbycustomers.

ConnectingtoGNDrepresentsa“0”whileconnectingtoVDDorkeepinginafloatingstaterepresentsa“1”.