Control44 is a 4 bit address, 4 bit data encoder and decoder combined in a single IC. This device can operate in either Encode or Decode mode. It uses 1kbps differential Manchester bit balancing with preamble and checksum. CTR44 is specifically designed to be used in RF remote control applications. It is available in 20pin SSOP, 18pin SOIC and PDIP packages.


Figure 1: Control44 in DIL package

Features

  • Operating voltage (temperature):
        3.0V-5.5V for standard version (-40°C to +125°C)
        2.0V-5.5V for low voltage version (-40°C to +85°C)
  • Draws <2mA without external load
  • 4 bit address and 4 bit data
  • 16different remotes with 4 controls each
  • Single packetised transmission for fast activation
  • Maximum usuage of the range capability of an RF module
  • Adequate preamble to settle data slicer in the receiver
  • Extra wake up preamble to allow for transmitter power up time requirements
  • Differential Manchester encoding of address, data and checksum
  • Synchronisation codes and checksum to reduce false triggering on noise
  • Suitable to be used with Narrow Band FM radio modules
  • Ceramic resonator or crystal oscillator up to 20MHz
  • Data rate up to 5.6kbps
  • Minimum external component requirement
  • 4 wire, push button and latched push button modes
  • Custom address, data bit variations available subject to minimum order quantity
Applications
  • Security and Alarm systems
  • Emergency assistance call system
  • Status reporting and monitoring systems
  • RF Remote control systems
  • Industrial controls
  • HVAC controls
  • Simple On/Off switching
  • Long range telecontrol with narrow band FM radios
Evaluation Platform: Control44 Evaluation Kit
 
 

Encoder Mode

Control44 can be put into Encoder Mode by connecting Mode (pin 2) to supply.
 
Figure 2: Control44 in Encoder Mode
 

Pin

Name

Input/Output

Description

1

NC

 

 

2

Mode

Input

RX=0V, TX=Vdd (no pull-up, only read at reset/power up)

3

TXE

Output

Active Low RF Transmitter Enable (Open drain, require 10k pull-up)4,6

4

RST

Input

Active Low Reset (Connect to user system reset or tie to Vdd)

5

VSS

Supply

Supply Ground

6-9

A3:A0

Input

Least significant 4 bits of Address (Internal pull-ups to Vdd)1,5

10-13
DB3:DB0 Input Least significant 4 bits of Data B (Internal pull-ups to Vdd)5

14

Vdd

Supply

4.5-5.5V supply (decouple with 100nF close to IC)

15

OSC2

Output

3.58MHz resonator2

16

OSC1

Input

3.58MHz resonator2

17

SEND

Input

Active Low Send Packet (Encoder Enable)3

18

TXD

Output

Encoded Address and Data to TXD input of RF Transmitter

Decoder Mode

Control44 can be put into Decoder Mode by connecting Mode (pin 2) to Ground.
 
Figure 3: Control44 in Decoder Mode
 

Pin

Name

Input/Output

Description

1

STB

Output

Positive going pulse on reception of valid data packet. 10ms duration

2

Mode

Input

RX=0V, TX=Vdd (no pull-up, only read at reset/power up)

3

NC

 

 

4

RST

Input

Active Low Reset (Connect to user system reset or tie to Vdd)

5

VSS

Supply

Supply Ground

6-9

A3:A0

Input

Least significant 4 bits of Address (Internal pull-ups to Vdd)1,5

10-13

DB3:DB0

Output

Least significant 4 bits of Data B5

14

Vdd

Supply

4.5-5.5V supply (decouple with 100nF close to IC)

15

OSC2

Output

3.58MHz resonator2

16

OSC1

Input

3.58MHz resonator2

17

Latch

Input

0V = latch DB3:DB0 until next packet
Vdd = clear DB3:DB0 after 150ms (no pull-up)

18

RXD

Input

Encoded Address and Data from RXD Output of RF Receiver

 

Notes:

  1. Only 4 of the 6 address bits are accessible. A5, A4 are set to 0 in CTR44
  2. OSC1,2 require a 3.58MHz ceramic resonator with internal capacitors like Murata CSTLA3M58G55-B). If a 2 pin resonator or crystal is used, then two 15pF caps are needed: one from OSC1 to 0V; one from OSC2 to 0V . 100W series resistor between OSC2 and crystal may be required when driving low frequency crystal with High Speed (H) CTR44H version
  3. If a low going pulse of between 10ms and 50ms is applied to SEND pin then a single packet will be transmitted
  4. After asserting TXE low (active), the coder allows 55ms for NBFM TX to power up and settle
  5. Absolute maximum source/sink current from each DB3:DB0 pin is 25mA
  6. TXE is an open drain output (no pull-up). Connect it to Vdd via a 10kW pull-up resistor
  7. MODE pin is only read at reset/power up. Connect to either Vdd (Encoder) or 0V (Decoder)
  8. Without external loads the CTR44 draws <2mA from 5V supply
  9. Standard version can be used down to 3V for <10MHz oscillator.
    Low voltage version can be used down to 2V for <4MHz oscillator
  10. High speed, CTR44H, version should not be used with Narrow Band FM radio modules

Encoded Data Packet Format

Transmission format is 1kbps differential Manchester encoding when using 3.58MHz rasonator. Oscillator frequency can be decreased to suit narrow band RF module data rate requirements. CTR44H running at 20MHz can be used with wideband radio modules for fast data transmission.
Figure 4: 1kbpsdifferential Manchester coding of 1 and 0
 
Control44 transmits a 6-byte burst, with 8 bits of preamble and 4 bits postamble. When firing up the Transmitter from cold Control44 puts in an extra 55ms especially for Narrow Band FM transmitter and receiver requiring longer power-up to stable data time.
Figure 5: Push button transmission with 55ms power-up preamble
 
The large amount of sync code, address and checksum reduce the likelihood of false calling on noise to an insignificant degree, while the breaking up of the data sequences with bit7 zeros is to reduce the likelihood of the decoder mistaking particular sequences in the data for sync codes.
 
Differential Manchester encoding coverts the 0000 into 11001100 which is the bit pattern equivalent to preamble required to settle adaptive data slicer in the RF receiver module.
 
Preamble   = 11001100  this byte is not decoded. 
Sync1 = 10111111 
Sync2 = 111100(A7)(B6)
DataA = 0(DA6-DA0) Reserved for future use and custom variants
DataB = 0(DB6-DB0)
Adress = 0(A5-A0)0
Checksum = sum of (DA7-DA0) + (DB7-DB0) + Adr(whole byte) truncated to 8 bits
 

This allows 6 bits of address and 2 data bytes per 60ms burst.

Figure 6: Control44 data packet
 
In the following example, Control44 in Encoder mode is set with the following.
DB3
DB2
DB1
DB0
A3
A2
A1
A0
1
0
1
0
1
0
0
1
 
The Control44 will packetise the address and data into the following format
Preamble
Sync1
Sync2
DataA
DataB
Address
Checksum
Postamble
11001100
10111111
11110000
00000000
00001010
00010010
00011100
0000
Figure 7: Sznchronisation codes, DataA, DataB, Address, Checksum and preamble
Application Modes

Mode

Setup

Description

4 wires

Latch = 0V (connect)
SEND = 0V (connect)

Continuous transmission like wire connection

Pushbutton

Latch = Vdd (connect)
SEND = 0V (push button)

Decoder outputs active only when transmitter is keyed

Latched Pushbutton

Latch = 0V (connect)
SEND = 0V (push button)

Decoder outputs hold state of last transmission

 
Ordering Information:

CTR44-000-SS Control 44 (=<4MHz) - No Frequency - Shrink Small Outline
CTR44-000-SO Control 44 (=<4MHz) - No Frequency - Small Outline
CTR44-000-DIL Control 44 (=<4MHz) - No Frequency - Plastic Dual In Package

CTR44L-000-SS Control 44 Low Voltage (=<4MHz) - No Frequency - Shrink Small Outline
CTR44L-000-SO Control 44 Low Voltage (=<4MHz) - No Frequency - Small Outline
CTR44L-000-DIL Control 44 Low Voltage (=<4MHz) - No Frequency - Plastic Dual In Package

CTR44H-000-SS Control 44 High Speed (4MHz - 20MHz) - No Frequency - Shrink Small Outline
CTR44H-000-SO Control 44 High Speed (4MHz - 20MHz) - No Frequency - Small Outline
CTR44H-000-DIL Control 44 High Speed (4MHz - 20MHz) - No Frequency - Plastic Dual In Package
 

Appendix

Relay circuit using Control44
Figure 8: Relay circuit using control44

It uses Schrack RY610012 or OKO relay which is rated 8A @ 250V AC or 30V DC and runs off at 12V DC / 100mA

Control44 Evaluation Kit is also available to evaluate CTR44 with single frequency Radiometrix radio modules.
 

Limitation of liability

The information furnished by Radiometrix Ltd is believed to be accurate and reliable. Radiometrix Ltd reserves the right to make changes or improvements in the design, specification or manufacture of its subassembly products without notice. Radiometrix Ltd does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. This data sheet neither states nor implies warranty of any kind, including fitness for any particular application. These radio devices may be subject to radio interference and may not function as intended if interference is present. We do NOT recommend their use for life critical applications.
The Intrastat commodity code for this device is: 8542 2145.

R&TTE Directive

After 7 April 2001 the manufacturer can only place finished product on the market under the provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive may demonstrate compliance to the essential requirements specified in Article 3 of the Directive, as appropriate to the particular equipment.
Further details are available on The Office of Communications (Ofcom) web site:
Licensing policy manual