MC145026

•MC145027•MC145028•SC41343•SC41344

MOTOROLA

1

Encoder and Decoder Pairs

CMOS

These devices are designed to be used as encoder/decoder pairs in remote

control applications.

The MC145026 encodes nine lines of information and serially sends this

information upon receipt of a transmit enable (TE) signal. The nine lines may be

encoded with trinary data (low, high, or open) or binary data (low or high). The

words are transmitted twice per encoding sequence to increase security.

The MC145027 decoder receives the serial stream and interprets five of the

trinary digits as an address code. Thus, 243 addresses are possible. If binary

data is used at the encoder, 32 addresses are possible. The remaining serial

information is interpreted as four bits of binary data. The valid transmission (VT)

output goes high on the MC145027 when two conditions are met. First, two

addresses must be consecutively received (in one encoding sequence) which

both match the local address. Second, the 4 bits of data must match the last

valid data received. The active VT indicates that the information at the Data

output pins has been updated.

The MC145028 decoder treats all nine trinary digits as an address which

allows 19,683 codes. If binary data is encoded, 512 codes are possible. The VT

output goes high on the MC145028 when two addresses are consecutively

received (in one encoding sequence) which both match the local address.

• Operating Temperature Range: – 40 to + 85°C

• Very–Low Standby Current for the Encoder: 300 nA Maximum @ 25°C

• Interfaces with RF, Ultrasonic, or Infrared Modulators and Demodulators

• RC Oscillator, No Crystal Required

• High External Component Tolerance; Can Use ± 5% Components

• Internal Power–On Reset Forces All Decoder Outputs Low

MC145027, MC145028 = 4.5 to 18 V

• Low–Voltage Versions Available:

SC41343 = 2.8 to 10 V Version of the MC145027

SC41344 = 2.8 to 10 V Version of the MC145028

• For Infrared Applications, See Application Note AN1016/D

PIN ASSIGNMENTS

MC145026

ENCODER

MC145028/SC41344

DECODERS

MC145027/SC41343

DECODERS

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

CTC

RTC

TE

Dout

VDD

A8/D8

A9/D9

RS

A4

A3

A2

A1

VSS

A7/D7

A6/D6

A5

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

D9

D8

D7

D6

VDD

Din

R2/C2

VT

A4

A3

A2

A1

VSS

C1

R1

A5

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

A9

A8

A7

A6

VDD

Din

R2/C2

VT

A4

A3

A2

A1

VSS

C1

R1

A5

* All MC145026 devices manufactured after date code 9314 or 314 are guaranteed over this wider voltage range. All previous designs using the

low–voltage SC41342 should convert to the MC145026, which is a drop–in replacement. The SC41342 part number has been discontinued.

Order this document

by MC145026/D

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

MC145026

MC145027

MC145028

SC41343

SC41344

P SUFFIX

PLASTIC DIP

CASE 648

ORDERING INFORMATION

MC145026P

Plastic DIP

MC145026D

SOG Package

MC145027P, SC41343P

Plastic DIP

MC145027DW, SC41343DW

SOG Package

MC145028P, SC41344P

Plastic DIP

MC145028DW, SC41344DW

SOG Package

D SUFFIX

SOG PACKAGE

CASE 751B

DW SUFFIX

SOG PACKAGE

CASE 751G

16

1

16

1

16

1

REV 2

1/98