Page 1

OCT. 26, 2001

GENERAL DESCRIPTION

SM5272B is a remote control decoder paired
with SM5262B utilizing CMOS Technology.
It has 12-bit tri-state address pins providing a
maximum of 531,411 (or 3

) address codes;

thereby, drastically reducing any code
collision and unauthorized code scanning
possibilities. SM5272B is available in
several options to suit every application
needs : variable number of data output pins,
latch or momentary output type.

FEATURES

* CMOS Technology
* Low power consumption
* Very high noise immunity
* Up to 12 tri-State code address pins
* Up to 6 data pins
* Wide range of operating voltage:
Vcc= 2.5 ~ 9 Volts
* Single resistor oscillator
* Latch or momentary output type
* Available in DIP and SOP package

APPLICATIONS

* Garage door
* Toys
* Remote control for industrial use

BLOCK DIAGRAM

Signal

Re-Shap

DIN

OSC1

Timing

Generator

OSC

OSC2

Address

Data

A6/D5 A11/D0

Address

Compare

Data

Compare

Decode

SM5272B

RF DECODER

Microelectronics Corp.

Page 2

OCT. 26, 2001

PIN ASSIGNMENTS ( DIP )

18 Vcc
17 VT
16 OSC1
15 OSC2
14 DIN
13 A11
12 A10
11 A9
10 A8

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

SM5272B

18 Vcc
17 VT
16 OSC1
15 OSC2
14 DIN
13 D0
12 D1
11 A9
10 A8

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

SM5272B-M2/L2

Vcc

OSC1

OSC2

DIN

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

SM5272B-M3/L3

18 Vcc
17 VT
16 OSC1
15 OSC2
14 DIN
13 D0
12 D1
11 D2
10 D3

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

SM5272B-M4/L4

18 Vcc
17 VT
16 OSC1
15 OSC2
14 DIN
13 D0
12 D1
11 D2
10 D3

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7

D4 8

SM5272B-M5/L5

18 Vcc
17 VT
16 OSC1
15 OSC2
14 DIN
13 D0
12 D1
11 D2
10 D3

Vss 9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6

D5 7
D4 8

SM5272BM6/L6

SM5272B

RF DECODER

Microelectronics Corp.

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 D0
14 D1
13 D2
12 D3
11 NC

SM5272BS-M5/L5

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7

D4 8

Vss 9

NC 10

Page 3

OCT. 26, 2001

PIN CONFIGURATION ( SOP )

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6

D5 7
D4 8

Vss 9

NC 10

SM5272BS

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 A11
14 A10
13 A9

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

12 A8

Vss 9

11 NC

NC 10

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

Vss 9

NC 10

SM5272BS-M2/L2

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 D0
14 D1
13 A9
12 A8
11 NC

SM5272BS-M4/L4

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 D0
14 D1
13 D2

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

12 D3

Vss 9

11 NC

NC 10

SM5272BS-M6/L6

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 D0
14 D1
13 D2
12 D3
11 NC

SM5272BS-M3/L3

A0 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8

Vss 9

NC 10

20 Vcc
19 VT
18 OSC1
17 OSC2
16 DIN
15 D0
14 D1
13 D2
12 A8
11 NC

SM5272B

RF DECODER

Microelectronics Corp.

A6/D5

I / O

Address input, each pin can be set to "0",
"1" , or floating.

Address input or data output.

A7/D4

Vss

A8/D3

I / O

POWER

I / O

A9/D2

A10/D1

I / O

A11/D0

I / O

DIN

Receive from Rf module.

Page 4

OCT. 26, 2001

OSC1

Resistor connected between these two pins
determine the system clock.

OSC2

Valid transmission indication.

Positive power supply.

POWER

PIN FUNCTION

No.

Pin Name

I/O

Function

Negative power supply.

SM5272B

RF DECODER

Microelectronics Corp.

Page 5

OCT. 26, 2001

Code Word

A group of Code Bits is called a code Word. A Code Word consists of 12 Address plus Data
bits followed by one Sync Bit. The 12 AD bits are interpreted as either address or data bits
depending on the SM5272B version used. Please refer to the diagrams below:

SM5272B

SM5272B-M2/L2

A10 A11

SYNC

SM5272B-M4/L4

SYNC

SM5272B-M5/L5

SYNC

SM5272B-M6/L6

SYNC

One Complete Code Word

SM5272B-M3/L3

SYNC

SM5272B

RF DECODER

Microelectronics Corp.

Page 6

Valid Transmission

After Power On SM5272B enters the Search Address mode, if SM5272B finds 2 consecutive
Address that matches the Address Pin setting of SM5272B then it will set VT high.

If VT is set high, SM5272B is still in search Address. After 2 consecutive Address that do not
match the setting on SM5272B, SM5272B will disable VT.

The timing are shown in the following diagram.

Latch or Momentary Data Output Type

After Power On SM5272B is set in Address search mode, if SM5272B finds 2 consecutive
Address that matches the Address setting of SM5272B. SM5272B will enter Data Compare
mode. It will compare perviously 2 receive data, if they match each then SM5272B will set VT
high and send data O/P.

SM5272B re-enters Address search mode, after 2 consecutive Address that do not match the
setting on SM5272B will disable VT and momentary's data but keep Latch's data intact.

1st Address

2nd Address

DIN

OCT. 26, 2001

DIN

DATA WORDS

DATA OUTPUT X

DATA OUTPUT Y

DATA PINS

(Momentary)

DATA OUTPUT X

DATA OUTPUT Y

DATA PINS

(Latch)

T= 2 CODE WORD WIDTH

SM5272B

RF DECODER

Microelectronics Corp.

Page 7

OCT. 26, 2001

OPERATION FLOWCHART

After Power On SM5272B enters the Search
Address mode, if SM5272B finds 2 consecutive
Address that matches the Address Pin setting
of SM5272B, it will set VT high.

It VT is set high, SM5272B is still in search
Address. After 2 consecutive Address that do
not match the setting on SM5272B, SM5272B
will disable VT.

Power ON

Address

match?

Set VT

Address

match?

Address

match?

Address

match?

Disable VT

YES

SM5272B

RF DECODER

Microelectronics Corp.

Page 8

OCT. 26, 2001

DECODER WITH DATA OUTPUT PINS

After Power On SM5272B is set in Address
search mode, if SM5272B finds 2 consecutive
Address that matches the Address setting of
SM5272B.
SM5272B will enter Data Compare mod. It will
compare previously 2 received data, if they
match then SM5272B will set VT high and send
data O/P.

SM5272B re-enters Address search mode, after
2 consecutive Address that do not match
setting on SM5272B will disable VT and
momentary's data but keep Latch's data intact.

Power ON

Address

match?

Address

match?

YES

Data match?

Address

match?

Address

match?

Disable VT and Remove the

Momentary data.

But keep the Latch Type

data intact.

YES

Active VT and

O/P data

YES

SM5272B

RF DECODER

Microelectronics Corp.

Page 9

OCT. 26, 2001

Single Resistor Oscillator

SM5272B's oscillator be constructed by connecting a resistor between OSC1 and OSC2 pin.
SM5272B's OSC frequency must be 1.4 to 6.8 times more than SM5262B.

Encoder OSC Frequency

SM5272B

RF DECODER

Microelectronics Corp.

Decoder OSC Frequency

Suggested oscillator resistor of SM5262B/ SM5272B:

SM5262B

SM5272B

4.7M OHM

750K OHM

3.0M OHM

390K OHM

2.2M OHM

270K OHM

1.2M OHM

160K OHM

R = 510K

R = 1.2 M

R = 2.7 M

R = 3.0 M

R = 3.3 M

R = 4.3 M

100

KHz

15 VOLTAGE

2.5

VOLTAGE

R = 100 K

R = 300 K

R = 620 K

R = 680 K

R = 820 K

R = 1.0 M

300

200

100

250

2.5

180

KHz

Page 10

DC ELECTRICAL CHARACTERISTICS

OCT. 26, 2001

Conditions

Unit

Limit

Symbol

Min. Typ. Max.

2.5

Vcc = 12 V
OSC stop
A0 ~ A11 open

STB

0.02

0.3

Parameter

Supply Voltage

Standby Current

Data Output
Driving Current

Data Output
Sinking Current

SM5272B

RF DECODER

Microelectronics Corp.

Vcc = 5V
V

= 1V

Vcc = 9V
V

= 1.8V

Vcc = 5V
V

= 4V

-3.5

Vcc = 9V
V

= 7.2V

-7.1

Page 12

ORDERING INFORMATION

Part No.

Package

SM5272B

18 Pin DIP

Part No.

Package

SM5272BS

20 Pin SOP

OCT. 26, 2001

SM5272B S

- X X

Logo

Empty: DIP TYPE
S: SO Package

M:Momentary type
L: Latch type

None: 0 Data Bits
2:Two Data Bits
3:Three Data Bits
4:Four Data Bits
5:Five Data Bits
6:Six Data Bits

Product No.

SM5272B

RF DECODER

Microelectronics Corp.

Date Code

Serial Number

ESD Protection Mark

xxx xx

Электронный компонент: SM5272B-4